forecast showed that they, in general, did not call attention to the fact that a crest forecast had
been revised.

RECOMMENDATION 2-17: Any significant change in the crest forecast from a previous crest
forecast should be highlighted at the beginning of the Flood Warning or Flood Statement.

FINDING 2-18: The forecast for the Flint River at Bainbridge received considerable media and
public attention when the river crested well below the forecasted level.

RECOMMENDATION 2-18: The SERFC must investigate the causes for the Bainbridge
forecast error and make the appropriate changes to the hydrologic forecast model as soon as
possible. When the appropriate modifications to the hydrologic model are completed, NWS
personnel, RFC and/or NEXRAD Weather Service Forecast Office (NWSFO), should make the
necessary effort to brief the Bainbridge public officials (and media) on their findings.

FINDING 2-19: Some communities, and perhaps emergency managers, were not as prepared
for the disastrous floods as they could have been if there were greater personal contact and
education on floods by NWS Warning Coordination Meteorologists (WCM) and Service
Hydrologists (SH).

RECOMMENDATION 2-19: NWS policy should require periodic (annual if possible) personal
visits by the WCMs and/or SHs to emergency management and other action agencies from the
state to the local level. These contacts should include a review of the flood threat to the local
community (emphasizing the threat to vehicular passengers) and a review of the hydrologic
services that the NWS provides. This educational process should specify what products are
available, how they can be used, and where they can most efficiently be obtained.

FINDING 2-20: The public’s perceived threat from Alberto appeared to lessen once it made
landfall.

RECOMMENDATION 2-20: The NWS and NOAA should take maximum advantage of the
recommendations from the 1995 Interdepartmental Hurricane and the NOAA Hurricane
Conferences, which focused on the inland effects of tropical cyclones, in order to enhance the
public’s perception of the dangers associated with landfalling tropical cyclones. In addition, the
WCMs in all areas which might be affected by the aftermath of decaying tropical cyclones
should reenforce the potential for severe flooding from such storms with the user community.

FINDING 2-21: The disaster team believes another possible contributing factor to the high
death count could be that the public was not adequately educated regarding the locations of

A-5


(s) (ay

Figure 2-4. QPF graphics for 24 hours ending 1200 UTC July 6, 1994: (a) observed,
(b) manual forecast, (c) ETA forecast, (d) RAFS forecast, and (e) AVN forecast.

17


Cour Dec.
55, 26! 1 7§

Natural Disaster Survey Report

Tropical Storm Alberto
Heavy Rains and Flooding
Georgia, Alabama, Florida
July 1994

us”

APRO5 1996

December 1995 DEPOSITORY 02444

U.S. DEPARTMENT OF COMMERCE
RONALD H. BROWN, SECRETARY

National Oceanic and Atmospheric Administration

Dr. D. James Baker, Administrator
Property of CSC Library

National Weather Service
Dr. Elbert W. Friday, Jr., Assistant Administrator
US Department of Commerce
NOAA Coastal Services Center Library
2234 South Hobson Avenue
Charleston, SC 29405-2413

QOS TI 144
APR 0” toor


[mi2, square miles; ft, feet above an arbitrary datum; ft?/s, cubic feet per second; *, new peak of record; a, approximately; d, discharge may have been affected by dam break; --, not
determined or not applicable; <, less than; >, greater than; number in ( ) is the ratio of the peak discharge to the 100-year flood discharge. Source: Recurrence intervals calculated
from U.S. Geological Survey data through 1990 water year. Other data from U.S. Geological Survey reports or data bases]

oa

Maximum prior to July 1994 Maximum in July 1994
Discharge
Drain- recurrence
USGS station age area. — Period of, Discharge Stage Discharge _ interval
number Stream and place of determination (mi?) record Year Stage (ft) (ft/s) Day (ft) (fs) (years)
APALACHICOLA RIVER BASIN
02358700 Apalachicola River near Blountstown, Fl 17,600 1920-94 1978 28.6
(1929) 172,000 10 27.39 225,000 50
02359000 —_Cipola River near Altha, Fl 781 1921-94 1926 33.35 25,000 12 29.60 14,200 30
02359170 Apalachicola River at Sumatra, Fl 19,200 1977-94 1990 13.82 179,000 13 15.05 221,000 55
CHOCTAWHATCHEE RIVER BASIN
02360500 Bast Fork Choctawhatchee River near Maryland City, Al 291 1953-63, 66-
70, 90, 94 1990 28.18 35,000 6 29.30 43,000 >100 (2.1)
02360275 Judy Creek near Ozark, Al 102 1951-77,90,94 1990 22.29 25,000 6 19.02 13,000 = 40
02361000 — Choctawhatchee River at Newton, Al 686 1922-27,35-94 1990 40.30 87,500 7 37.78 58,000 >100 (1.4)
02362240 Little Double Bridges Creek near Enterprise, Al 21.4 1986-94 1990 13.90 7,950 6 16.45 #14,200 >100 (2.5)
02365500  Choctawhatchee River at Caryville, Fl 3,499 1929-94 1929 27.10 206,000 9 «23.85 164,000 >100 (1.3)
02366500 — Choctawhatchee River near Bruce, Fl 4,384 1931-82, 85-94 1929 29.20 220,000 11 26.76 | 165,000 >100 (1.5)
YELLOW RIVER BASIN
02368000 Yellow River at Milligan, F1 624 1938-94 1990 19.00 51,500 8 17.55 40,200 40
02369000 Shoal River near Crestview, Fl 474 1938-94 1975 15.58 25,200 8 14.82 22,600 25
ESCAMBIA RIVER BASIN
02371000  Conecuh River near Troy, Al 257 1944-68,90,94 1990 19.41 33,000 7 15.58 17,700 10
02371500  Conecuh River at Brantley, Al 500 1938-94 1990 24.44 25,700 22.37 17,000 10
02421000  Catoma Creek near Montgomery, Al 190 1949, 53-94 1990 29.78 49,100 8 26.07 22,800 10



Table D-3. Chattahoochee River at Columbia L&D TW COLAI, Flood Stage 113 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)

07/04/94 93.0 | Crest near 103 this afternoon 1:00 pm

07/05/94 108.3 | 110-111 tonight 10:35 am
07/06/94 110.0 | Crest 119-120 on 7th 11:05 am
07/07/94 At crest near 120 today 12:45 pm
07/08/94 Fall below FS tonight 12:15 pm
07/9/94 Below FS, Fall below 92 12th 12:25 pm
07/10/94 92-93 next few days 11:25 am

07/11/94 92.0 | 92-93 next few days 11:55 am
07/12/94 92.0 | Falling below 92 today 11:15 am
07/13/94 86.2 | Below 92 and falling

11:45 am

Crest: 123.98 ft, about noon 7/7/94
New record level
Previous Flood of Record: 123.29 ft, 3/19/90

D-5




Stage (ft)

Altamaha River at Baxley Altamaha River at Doctortown

July 1994 July 1994
100 45
80h ees ara
gage”
60 e
o
2
s
40 ao
PO ae
13.5 7 9 11 13 15 17 19 21 23 25 27 29 31 13.5 7 9 11 1315 17 19 21 23 25 27 29 31
Time (days) Previous reocrd : 91.51 ft 1/22/25 Time (days) Previous record: 18.6 ft1/23/25
Peak 2 B41 f7N6194 Peak 21457 ft 79104
Flood stage 1 745 ft Flood stage 214 ft
Oconee River at Penfield
July 1994

Stage (ft)

123.4 5 6 7 8 9 10111213 14 15 16 17 18 19 20

Time (days) Previous record : 23.23 ft 347/90
Peak 24 ft 7/06/94
Flood stage 11 ft

C4


computer systems at NWS offices; these systems were not available at the offices affected by
Alberto. In Stage I, the hourly digital precipitation data from Stage I are combined with
Geostationary Operational Environmental Satellite (GOES) infrared satellite data and rain gage
data to perform additional quality analysis and screen out anomalous data. Stage III Precipitation
Processing involves interactive analysis and assimilation of gridded precipitation estimates from
all WSR-88Ds covering a River Forecast Center (RFC) area of responsibility. The resulting
hourly precipitation product is used as gridded input to the RFC’s hydrologic modeling system.
In the summer of 1994, the WSR-88D Stages II and III Precipitation Processing were being run
on pre-AWIPS workstations at the Arkansas-Red Basin RFC and the North Central RFC for
their areas of responsibility. The gridded precipitation products are then input to the NWS River
Forecasting System (NWSRFS) Interactive Forecast Program (IFP), which is also run on the
workstations.

The consensus of NWS field personnel, cooperating agencies, and the media was that the
WSR-88Ds did a fine job of representing the areal coverage of the precipitation. WSR-88D
images appeared on television and in the newspapers. A WSR-88D storm total precipitation
color graphic is shown on the cover of this report. While the representation of the areal
coverage was good, the WSR-88D underestimated the amount of precipitation associated with
the Alberto warm tropical event.

FINDING 2-3: The WSR-88D Stage I Precipitation Processing, which runs in
the Radar Products Generator, does not currently use rain gage data to provide
potentially better quantitative estimates of the precipitation.

RECOMMENDATION 2-3: Rain gage data must be included in the WSR-88D
Stage I Precipitation Processing as soon as possible, so that the radar-rainfall can
be adjusted to avoid underestimation of rainfall associated with warm tropical
events.

FINDING 2-4; The number of automated rain gages under the umbrellas of
many of the WSR-88Ds in the area affected by Alberto was inadequate to
effectively incorporate rain gage data into the Stage I Precipitation Processing.

RECOMMENDATION 2-4: The rain gage data network must be expanded and
the reporting characteristics of existing sites modified to provide more timely data
to produce a higher quality WSR-88D precipitation estimate.

Because the only usable information available from the WSR-88D was visual, it was only used
to "flavor" SERFC forecasts. The SERFC staff looked for downstream/upstream rainfall
concentrations in the WSR-88D images to manually adjust timing and distribution of the
precipitation. The hourly digital rainfall (HDRAIN) products from Stage I Precipitation
Processing could not be used due to lack of workstations to process data and incorporate them
into hydrologic models at the SERFC.


Additional major flash flooding occurred in numerous counties stretching from central Georgia
westward and southward into southeastern Alabama. Considerable property and road damage
resulted due to this flooding, but the loss of life was restricted to vehicle-related incidents.
Sumter County is out of range of WSO Macon’s NOAA Weather Radio (NWR), which is
68 miles away (the tone alert range is 40 miles). All the Sumter County patrol cars are
equipped to monitor NWR, but it blocks out other radio communications so is not used much.
There is a similar situation in Bainbridge, Georgia. The Emergency Operation Center has NWR
but doesn’t use it nor rely on it. Additionally, emergency operation centers should have the
National Attack Warning System (NAWAS), which is a telephone communication link. But,
again, not every county in Georgia has this system. The Georgia Emergency Management
Agency rebroadcasts NWS forecasts on radio and faxes hard copies of NWS watches/warnings
to its six field offices across the State. Sumter County has no means of direct contact (other
than phone) or automated dissemination from NWS. It does not receive NOAA Weather Wire
Service (NWWS) or NAWAS and is out of range of NWR from WSO Macon. The same
situation applies in Calhoun County, Alabama. Florida now has NAWAS in each county,
however, it is in the Sheriff’s office or connected to a 911 dispatch but not necessarily located
in an emergency management agency/emergency operation center. Word does not always get
through to emergency management agencies.

FINDING 2-11: The Sheriff/Emergency Management Agency Director for
Sumter County, Georgia, receives weather watches and warnings from the public
broadcast media. The county does not receive the NAWAS transmissions and is
on the outside fringe of NWR reception (Americus is 68 miles from the nearest
NWR transmitter). The NWR tone alert does not work reliably in the county
because of this distance.

RECOMMENDATION 2-11: NWS should work with FEMA to ensure that
every county emergency management agency/emergency operation center in
Alabama, Florida, and Georgia has a communication link to NAWAS.
Additionally, the Gore Initiative should be implemented as soon as possible to
expand the NWR network of transmitters to reach 95 percent of the population.

FINDING 2-12: The Sheriff of Sumter County, Georgia, as with many other
emergency management officials in the impacted area, expressed a high degree
of frustration in making residents aware of the danger from the floodwaters and
of the need to evacuate. Some of the deaths that occurred were people who had
been warned (more than once) to evacuate but failed to act until it was no longer
safe to do so. No flash flood/flood anywhere near the magnitude of this event
had ever occurred in this area; and residents were, for the large part, unable to
realize the dangers they faced until it was too late.

RECOMMENDATION 2-12: More emphasis should be placed on public

awareness and preparedness training for flood and flash flood events. The
continued high number of vehicle-related deaths during floods and flash floods

31


APPENDIX B

U.S. GEOLOGICAL SURVEY PEAK FLOWS

The following chart, from U.S. Geological Survey data, shows a summary of the

peak stages and discharges during floods from July 4 to July 16, 1994, in Georgia, Florida,
and Alabama.

B-1


2.2.4 DATA EXCHANGE WITH COOPERATING AGENCIES

The U.S. Army Corps of Engineers reported receiving good information via the RFC
HYDROMET system but wanted access to the WSR-88D data. They had ports allocated on
most WSR-88D systems for their use but at the time did not have their PUP emulator systems
in place to interface with these ports.

2.3 FLOOD FORECASTING SERVICE

The flooding in this event occurred on rivers in Georgia, Alabama, and Florida. The SERFC,
located in Peachtree City, Georgia, has river forecast responsibility for all rivers affected by the
event. Hydrologic Service Area (HSA) responsibility was shared by three offices:

NWSFO Atlanta has HSA responsibility for the rivers in Georgia, including the
Chattahoochee River along the Georgia-Alabama border.

NWSFO Birmingham has HSA responsibility for rivers in Alabama and the
Florida Panhandle west of the Apalachicola River.

NWSO Melbourne has HSA responsibility for rivers in Florida, excluding the
rivers in the Florida Panhandle west of the Apalachicola River but including the
Apalachicola River.

HSAs are defined for the issuance of longer-fused Flood Warnings and Statements, while the
County Warning Area (CWA) determine responsibility for the shorter-fused Flash Flood
Watches and Warnings. Figure 2-8 contains a map with the HSA boundaries and Figure 2-9
contains the CWA boundaries. CWA responsibility in the flooded area was shared by NWSFO
Atlanta, WSO Columbus, WSO Macon, NWSFO Birmingham, WSO Montgomery, NWSO
Tallahassee, and WSO Pensacola.

2.3.1 FLASH FLOODING

All the offices with CWA responsibility were involved in issuing Flash Flood Warnings and
Statements for their areas. RFC flash flood guidance and NMC QPF were used to create the
Flash Flood Watch and Warning products. The local offices did not refine the NMC QPF.
Table 2-1 below shows the number of public products related to Alberto that were issued by
each office.

The early part of this event was marked by major flash flooding, particularly in west-central
Georgia and southeast Alabama. Although several counties suffered major flash flooding, the
loss of life in Sumter County, Georgia, was extremely high compared to surrounding areas.
Sumter County received the heaviest 24-hour rainfall during the storm with 21.10 inches falling
at Americus in the period ending 7 a.m. July 6. The resultant flash flooding and flooding
claimed 15 lives in this county.

27


[mi?, square miles; ft, feet above an arbitrary datum; ft°/s, cubic feet per second; *, new peak of record; a, approximately; d, discharge may have been affected by dam break; --, not
determined or not applicable; <, less than; >, greater than; number in ( ) is the ratio of the peak discharge to the 100-year flood discharge. Source: Recurrence intervals calculated
from U.S. Geological Survey data through 1990 water year, Other data from U.S. Geological Survey reports or data bases]

‘Maximum prior to July 1994 Maximum in July 1994
Discharge
Drain- recurrence
USGS station age area Period of Discharge Stage Discharge interval
number Stream and place of determination (mi?) record Year Stage (ft) —_ (ft/s) Day (ft) (ft/s) (years)

FLINT RIVER BASIN--Continued

02346500 —_ Potato Creek near Thomaston, Ga 186 1938-73, 90,94 1990 9.19 12300 6 120 *28,000 >100 (1.9)
02347500 ‘Flint River near Culloden, Ga 1,850 1913-31, 37-94 1929 38.40 92,000 6 45.73 *100,000 >100 (1.2)
02349030 Cedar Creek near Rupert, Ga 41.1 1979-94 1979 4.72 580 6 7.50 *2,400 >100 (1.1)
02349350 Buck Creek near Ellaville, Ga 146 1929-94 1990 9.67 3,730 6 11.31 *7,800 >100 (1.1)
02349500 Flint River at Montezuma, Ga 2,900 1897, 1905-94 1897 26.00 97,000 8 34.11 *136,000 >100 (1.4)
tg (02349900 Turkey Creek near Byromville, Ga 45.0 1951-94 1981 13.82 4820 6 14.29 *5,820 >100 (1.2)
02350512 —_ Flint River at Oakfield, Ga 3,880 1967-75, 88-94 1990 27.37 50,200 10 401 *112,000 >100 (1.4)

02350520 _Little Abrama Creek near Doles, Ga 3.77 1965-75, 94 1967 5.99 652 «6 7.06 *840 >100 (1.1)
02350600 — Kinchafoonee Creek near Preston, Ga 197 1943, 48-78,

87-94 1990 12.16 14500 6 11.66 12,400 100
02350685  Choctahatchee Creek trib near Plains, Ga 0.32 1977-94 1982 2.42 3 6 9.25 *625 >100 (3.1)
02350900 — Kinchafoonee Creek near Dawson, Ga 527 1943, 48-66,

73, 85-94 1943 23.00 15,000 7 26.56 *29,500 >100 (1.7)
02351500  Muckalee Creek near Americus, Ga 140 1948, 1963-83,

94 1948 12.50 9,000 6 19.50 d ¥33,500 >100 (4.0)
02351890 | Muckalee Creek near Leesburg, Ga 362 1943, 48, 80-94 1943 - 18,000 6 29.1 d*64,400 >100 (5.0)
02352500 ‘Flint River at Albany, Ga 5,310 1893-1994 1925 37.80 92,000 11 43.0 *120,000 >100 (1.3)
02353000 —_—Fiint River at Newton, Ga 5,740 1925, 29,38-94 1925 41.30 94,000 13 45.25 *100,000 >100 (1.2)
02353500 —Ichawaynochaway Creek at Milford, Ga 620 1906-07, 16,

25, 40-94 1916 17.20 15,500 7 23.20 *53,000 >100 (3.0)
02356000 ‘Flint River at Bainbridge, Ga 7,570 1897, 1905-94 1925 101,000 14 37.20 *108,000 >100 (1.1)

02357000 Spring Creek near Iron City, Ga 485 1938-78, 83-94 1975 19.43 17,700 8 19.95 12,900 25



(2) greater emphasis in routine preparedness activities on the dangers posed to passengers in
vehicles in flood situations and posed by heavy rains and flooding, including floods caused by
decaying tropical cyclones.

The two deaths in Alabama involved (1) a man who, in the early hours of Wednesday, July 6,
drove his vehicle around a barricade and then slid into the swollen Choctawhatchee River and
(2) a 13-year-old boy playing in a storm drain, was subsequently swept away by the floodwater
on July 5, and later died from his injuries. Table 2-4 contains a chronicle of the 31 deaths in
Georgia from The Atlanta Constitution newspaper article dated July 31, 1994.

Table 2-4. Georgia flood-related deaths from Tropical Storm Alberto

July 5, 1994

John F. Peavy, male, age 54, truck hydroplaned and hit a wrecker.

Richard Rodgers, male, age 20, car crashed.

Jack S. Shriver, male, age 40, trying to tie down a small bridge in Line Creek.

Teresa Beyahf, female, age 31, car hit a washed-out road.

Gloria Dixon, female, age 16, current pulled her under in a ditch after she rescued dog.

Monty Folsom, male, age 35, truck caught in whirlpool that formed in a flooded parking lot and was pulled through an 8-foot culvert.
Lisa Sheppard, female, age 25, passenger in truck with Folsom.

William Miller, male, age 62, car was swept into the Towaliga River.

July 6, 1994

Eugene Marner, male, age 40, truck and trailer swept away by wall of water.

Kent Marner, male, age 12, passenger in truck and trailer swept away by wall of water.

Roger Cornelius, male, age 40, passenger in truck and trailer swept away by wall of water.

Josephine S. Anderson, female, age 70, car went into a creek.

Walter Davenport Stapleton, III, male, age 17, died stringing telephone lines on Lake Corinth when his boat overturned (upstream
dam break caused log to ram boat; current pulled him over the dam).

Oscar Brown, male, age 84, mobile home crushed by water.

Idell Jackson, female, age 67, home crushed by water.

Gloria Tatum, female, age 28, car washed off bridge into flooded creek.

Tomeko Y. Woodham, female, age 20, car went into a creek.

Chad Jones, male, age 18, trying to rescue animals by using an inner tube on the Towaliga River.

Douglas K. Bassett, male, age 32, trying to cross a train trestle over the Towaliga River.

Hilton Howard, male, age 42, car went into a creek.

Freddie Hawkins, male, age 35, bridge washed out and truck was swept away.

Kedrick Hawkins, male, age 16, passenger in truck that was swept away when bridge washed out.

Kourtney Hawkins, male, age 8, passenger in truck that was swept away when bridge washed out.

Kathy R. Hurley, female, age 28, car was swept into a creek.

John Hurley, male, age 2, car was swept into a creek.

July 7, 1994
William Wallace, male, age 41, died searching for his mother (she was later found in a shelter).

July 8, 1994

Kason Mallory, female, age 4, passenger in father’s car which plunged into the Flint in Albany.
Shabazz Mallory, male, age 2, passenger in father’s car which plunged into the Flint in Albany.

July 10, 1994
Ishkabah T. Linkhomn, male, age 28, swept away by the Flint.

July 13, 1994
Pearlie Mae Brantley, female, age 59, drowned when Flint River floodwaters filled her home.

July 14, 1994
Maureen Johnson, female, age 71, car plunged into a creek in Terrell County.

37


Table D-11. Apalachicola River at Woodruff Dam TW WDRFI, Flood Stage 66 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/05/94 59.3 | 62 66 65 63 60 10:50 am
07/06/94 63.2 | 68 73 72 68 64 Cr 73 8th 10:50 am
07/07/94 67.16 | 73 72 68 64 60 Cr 73 8th 12:40 pm
07/08/94 73.47 | 75 74 72 68 65 Cr 75-76 tonight 12:45 pm
07/09/94 75.77 | 76 75 75 74 72 Cr 77-78 tonight 11:55 am
07/10/94 75.66 | 75 75 73 71 69 Crested...falling 11:55 am
07/11/94 74.40 | 74 73 71 69 67 12:05 pm

Crest: 76.29 ft, 4 am 7/10/94
New record level
Peak discharge 225,000 cfs

Previous Flood of Record: 74.2 ft, 3/21/90

D-13



WSR-88D

NEXRAD Weather Service Forecast Office
National Weather Service River Forecast System
NOAA Weather Wire Service

Office of Atmospheric Research
prognostication chart

Principle User Processors (WSR-88D)
Quantitative Precipitation Forecast
Regional Analysis and Forecast System
River Forecast Center

remote job entry

River Statement

Southeast River Forecast Center

Service Hydrologists

site identification

Universal Generic Code

U.S. Geological Survey

Universal Coordinated Time

Warning Coordination Meteorologist
Weather Forecast Branch

Weather Forecast Office

Weather Service Forecast Office

Weather Service Office

Weather Surveillance Radar-1988 Doppler

xiv


PREFACE

A decaying tropical system, previously known as Tropical Storm Alberto, produced torrential
rainfall which resulted in some of the worst flooding ever observed across portions of the
States of Georgia, Alabama, and Florida during July 1994. The rainfall led to exceptional
flooding across central and western Georgia, eastern Alabama, and the Florida Panhandle.
Five river basins were particularly hard hit: (1) the Flint River Basin in western Georgia,
(2) the Ocmulgee River Basin in central Georgia, (3) the Chattahoochee River Basin along
the Georgia-Alabama state line, (4) the Choctawhatchee River Basin in Alabama, and (5) the
Apalachicola River Basin in Florida. The flooding claimed 33 lives and caused damages
estimated at close to $750 million. A National Oceanic and Atmospheric Administration
(NOAA) disaster survey team assembled for its first meeting in Peachtree City, Georgia, on
the morning of July 18, 1994. All aspects of weather and flood warning systems--from data
acquisition to user response--were surveyed to determine NOAA’s effectiveness and to
recommend improvements if deficiencies were found. This report gives the results and
findings of the survey team.

The survey team consisted of the following individuals:

Dr. William H. Hooke, Team Leader, Program Director for Weather
Research, Office of Atmospheric Research, Silver Spring, Maryland

Christine Alex, Meteorologist, Office of Meteorology, National Weather
Service Headquarters, Silver Spring, Maryland

Aris Georgakakos, Professor of Engineering, Georgia Institute of
Technology, Atlanta, Georgia (independent consultant)

Anton Haffer, Meteorologist in Charge/Area Manager, NEXRAD National
Weather Service Forecast Office, Phoenix, Arizona

Edwin May, Deputy Regional Hydrologist, Hydrologic Services Division,
Southern Region Headquarters, National Weather Service, Fort Worth, Texas

Debra Van Demark, Technical Leader, Hydrologist, Office of Hydrology,
National Weather Service Headquarters, Silver Spring, Maryland


Chattahoochee River - This river is somewhat more controlled by impoundment structures than
the other rivers impacted by Alberto, but the volume of water still caused considerable flooding
along the lower half the river. At Columbia Tailwater, a record crest more than 2 feet higher
than the previous record, and over 12 feet above flood stage, was observed.

Apalachicola River - The Flint and Chattahoochee Rivers join at Lake Seminole, which is
formed by Woodruff Dam. Outflow from Woodruff Dam flows down the Apalachicola River.
The excessive inflow into Lake Seminole forced high discharges from Woodruff Dam (the peak
discharge was 224,486 cfs on July 10th) and caused record flooding at Blountstown.

Choctawhatchee River - Major flooding occurred along this river in Alabama and Florida as
a crest 15-20 feet above flood stage moved down the basin. This crest was about 4 feet below
the record crests. Considerable damage resulted at Newton and Geneva, Alabama, and
Caryville, Florida. Additional major damage occurred in Dale County, Alabama, and Holmes
County, Florida.

FINDING 2-15: The disaster survey team found a high degree of satisfaction
from emergency managers, the media, and the public with the river forecast
services they received during this event. In particular, the impact statements and
relationship to recent and historical flood levels were judged valuable information.

RECOMMENDATION 2-15: NWS HSA offices should make every effort to
include up-to-date and informative impact statements in all Flood Warnings and
Flood Statements.

FINDING 2-16: There were several suggestions from emergency managers and
the media that the public river forecasts be updated more frequently. The normal
procedure presently is to issue the Flood Statements once per day in late morning
or early afternoon. In particular, an early morning update was suggested to
provide current information so the public can make more informed decisions on
commute, daily activities, or evacuation activities.

RECOMMENDATION 2-16: NWS offices should make every attempt to update
Flood Warnings and Flood Statements more than once per day.

FINDING 2-17: Several users suggested that changes in crest forecast values be
highlighted at the beginning of Flood Statements. An analysis by the disaster
survey team of the Flood Statements issued during this event where the crest
forecast was revised from the previous forecast showed that they, in general, did
not call attention to the fact that a crest forecast had been revised.

RECOMMENDATION 2-17: Any significant change in the crest forecast from

a previous crest forecast should be highlighted at the beginning of the Flood
Warning or Flood Statement.

34



Ocmulgee River at Hawkinsville
July 1994

0
123.4 5 6 7 8 8 10111213 14 15 16 17 18 19 20

Time (days) Previous record : 36.5 1/21/25
New record 140.91 70994
Flood stage 25 ft

Ocmulgee River at Lumber City
July 1994

F nee :
123 4 5 6 7 8 9 10111213 14 15 16 17 18 19 20

Time (days) Previous record : 26.3 ft 1/21/25

Peak 1 24.59 ft 715/94
Flood stage: 18 ft

Ocmulgee River at Abbeville
July 1994

25 TT sas a

yp
8S

a

Ss

Stage (f)

8B 9 1011 1213 1415 16 17 18 19 20

Time (days) Previous record : 20.3 ft 1/23/25
Peak 1284 fR7A194
Flood stage =: 12 ft
Altamaha River at Charlotte
July 1994
5
20
a
510
5 :
4 rhe

1 3 5 7 8 11 13 18 17 19 24 23 25 27 29 31

Time (days) Previous record : 31.2 ft 1/22/25
Peak 223.3 7A 6/94
Flood stage 15 ft


Table D-6. Kinchafoonee Creek at Preston PRSG1, Flood Stage 7 ft

Date Forecast (ft)

Issue Time (EDT)

07/04/94 Crest near 7 6th

10:15 am

Crest: 11.66 ft, 5 am 7/06/94
Previous Flood of Record: 12.16 ft, 3/17/90

D-8

07/05/94 5.6 | Crest near 7 6th 10:35 am
07/05/94 6.7 | Crest near 8 6th 3:30 pm

07/06/94 9.4 | Crest near 10 today 11:05 am
07/06/94 10.65 | Falling...below FS on 10th 10:10 pm
07/07/94 8.93 | Falling below FS on 8th 12:45 pm
07/08/94 7.08 | Falling below FS today 12:15 pm



CL. re — A

é

Natural Disaster Survey Report

Tropical Storm Alberto
Heavy Rains and Flooding
Georgia, Alabama, Florida
July 1994

_ rr Q8/88/94 17°57
a STM PRECIP 36 STP
‘ yf 124 NM 1.1 NM RES
G7/G7794 18:29

j CN RDA-KNKX 32-32/13N
Waar aet Laie

rg aU eam et
fen oO Af oe a en 18:31

-

MAG=1X FL= 3 COM=1

°
3
°
Zz

DAE SWONAUAWNHOOZ
VSovTVTAAHG900H

O15 Uo 1787 KIGX
PROD RCVD: STP OT
KJGK 1952

9871164 LINE 3
REQUESTED DSCNCT

, HARDCOPY

HARDCOPY REQUEST
ACCEPTED

ones U.S. DEPARTMENT OF COMMERCE
1995 National Oceanic and Atmospheric Administration

National Weather Service, Silver Spring, Maryland


Chapter 3. Issues Highlighted by the Event ...... 0.2.6... e eee eee 41

3.1. Transition/Staffing/Modernization Vulnerabilities ............... 41
3.1.1 Transition... 1... eee 41 ,
3.1.2 Staffing 2... eee ee eee 43 ‘
3.1.3 Modernization 1... 6... eet 44 4
3.2 Emerging Challenges .. 0.00.00. 0c cece eee eens 45 ‘
3.2.1 Expanding the Use of Improved Communication
Technology 6... 0. ee eee 45 2
3.2.2 Improved Coordination Between NWS and FEMA .......... 46
Appendices: :
A - Summary of Findings and Recommendations ............200000 eee ee Al
B - U.S. Geological Survey Peak Flows... 1... 0. eee ees B-1
C - Selected Hydrographs ©... 0.2... ee eee C-1
D - Forecasts Issued by Southeast River Forecast Center by Forecast Points ........ D-1
E - Disaster Survey Team Contacts... 0... ee eee E-1
:
iv



wT

WSR-88D Coverage as of Jul

= WSR-88D Coverage

7-7-94



Table D-13. Chipola River near Marianna MALFI, Flood Stage 19 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)

07/04/94 10.4 | Crest near 16 7th 10:10 am
07/05/94 10.9 | Crest near 16 7th 10:50 am
07/06/94 12.1 | Crest near 16 7th 10:50 am
07/06/94 Crest near 30 8th 5:30 pm

07/07/94 14.0 | Crest near 30 8th 12:40 pm
07/08/94 18.0 | Crest 24-25 9th pm 12:45 pm
07/09/94 22.8 | Crest near 25 tonight 11:55 am
07/10/94 23.4 | 24-25 next few days 11:55 am
07/11/94 Slow fall 12:05 pm

Crest: near 24 ft, 07/10/94
Previous Flood of Record: E27.0 ft, 4/15/75

D-15



Table D-8. Flint River at Albany ABNGI, Flood Stage 20 ft

Date Latest

Forecast (ft)

Issue Time (EDT)

fall

Report (ft)

07/05/94 7.5 | Crest 30-31 11th 10:35 am
07/05/94 11.0 | Crest 36-37 11th 3:30 pm

07/06/94 19.8 | Crest near 40 9th 11:05 am
07/07/94 32.69 | Crest near 44 10th 12:45 pm
07/07/94 E41.00 | Crest near 45 9th 09:45 pm
07/08/94 F41.95 | Crest 45-46 9th pm 12:15 pm
07/09/94 F41.45 | Crest 45-46 tonight 12:25 pm
07/10/94 F42.09 | Crest 45-46 tonight 11:25 am
07/11/94 F42.65 | Remain 42-43 next few days then slow | 11:55 am

Crest: 43 am 7/11/94
New record level

07/12/94 FA1.77 | 40 38 35 31 28 11:15 am

Previous Flood of Record: 37.80 1/21/25
USGS Measurements: 42.34 ft = 119,000 cfs, about noon 7/10/94
Crest discharge 120,000 to 125,000 cfs

D-10

ee

es


undoubtedly concerned about recurring drought conditions, similar to those which occurred
during the summer of 1993. However, June 1994 brought much wetter conditions over most
of the Southeast. In fact, the rainfall in June resulted in some localized flash flooding and
even some limited, mostly minor river flooding across portions of the Southeast. At the
beginning of June, moderate-to-extreme drought conditions existed across a considerable
portion of the Southeast, especially over Georgia and South Carolina. But due to the wet
June, by the time of Alberto’s arrival in early July, hydrologic conditions across much of the
Southeast had returned to near normal, or just slightly drier than normal. Thus, the wet June
certainly was a factor in the evolution of the July flood.

There is little question as to the cause of the torrential rainfall associated with Alberto and its
remnants. While heavy precipitation accompanies nearly every tropical system, excessive
rainfall was produced by the remnants of Alberto due to two main factors: (1) the slow,
forward motion of the system and (2) the meandering, looping (retrogressive) nature of the
system’s track. These characteristics contributed to rainfall accumulations that, in several
places, exceeded 20 inches. Noteworthy was Americus, Georgia, which received a storm
total of 27.61 inches (July 3-9), including a 24-hour total of 21.1 inches (July 5-6). While
such amounts are certainly not unprecedented, they are nonetheless rare, even with decaying
tropical systems.

Figure 1-4 shows the National Weather Service (NWS) Climate Analysis Center’s storm total
isohyetal analysis. The heaviest rains (16 inches or greater) fell in a relatively narrow band
across southwestern Georgia and southeastern Alabama. Some of the worst flash and urban
flooding occurred in this excessive rainfall area, as evidenced by the 15 fatalities that
occurred in the vicinity of Americus, Georgia. In contrast, a far larger area was inundated
with 8 or more inches of rainfall. It was this heavy precipitation that fell over a fairly large
area that generated tremendous runoff and resulted in the widespread river flooding.

1.3.3. DESCRIPTION OF THE FLOODING

Figure 1-5 is a composite figure combining portions of Figures 1-1 through 1-4. This figure
shows the inland track of Alberto and its remnants, the area enveloped by the 8-inch rainfall
isohyet, the major rivers affected by flooding, and the counties that were Presidentially
declared disaster areas.

As is typical with flood events of this magnitude, widespread major river flooding evolves
from flooding which first manifests itself in the form of urban, small stream, and flash
flooding. Such was the case with this flood. The first reports of flooding included flooded
roads, underpasses, culverts, and the like. Since the heaviest rains were generally close to
the path of the center of Alberto, the pattern of flooding essentially followed the path of the
storm center. Thus, flooding first broke out across portions of the Florida Panhandle and
southeast Alabama, then across southwestern portions of Georgia. Flooding later broke out
across much of the remainder of western and central Georgia. As rainfall persisted and soils
became saturated, small streams and rivers began to overflow; and small dams were



The NWS should also give more emphasis to development of all-hazard telecommunications
capability for NWR. A FEMA representative was concerned about NWS’ capability/staffing
implications to handle FEMA information on "all-hazards" NWR. The essence of this issue is
whether NWS has sufficient ability/staffing to support "all-hazards" operation of NWR since
post-disaster information provided by FEMA is very high-volume traffic.

FINDING 3-11: The limited ability of the NWS to interact with FEMA raised
the concern that the NWS may not be able to synchronize with FEMA and
effectively operate an "all hazards" NWR.

RECOMMENDATION 3-11: The NWS must be careful not to commit to

operating an “all-hazards" NWR without considering issues, such as staffing and
length of the NWR program cycle.

47


Table D-20. Altamaha River near Baxley BAXGI, Flood Stage 74.5 ft

Date

Latest

Report (ft)

Forecast (ft) Issue Time (EDT)

07/06/94

70.8

71 72:72:74.5 75

11:05 am

Crest: 84.10 ft, 8 pm 07/16/94
Previous Flood of Record: 84.2 ft, 3/12/71
USGS Measurement: 84.03 ft = 103,000 cfs about noon 7/16/94

D-22

07/07/94 71.29 | Crest near 81 16th 12:45 pm
07/08/94 71.64 | Crest near 81 17th 12:15 pm
07/09/94 71,90 | Crest near 83 17th 12:25 pm
07/10/94 72.18 | Crest near 83 17th 11:25 am
07/11/94 72.57 | Crest near 83 17th 11:55 am
07/12/94 73.21 | Crest near 83 17th 11:15 am
07/13/94 75.10 | Crest 84-85 17th 11:45 am
07/14/94 80.16 | Crest 84-85 17th 11:50 am
07/15/94 82.82 | Crest 84-85 16th pm 11:40 am
07/16/94 83.97 | Crest 84-85 this evening 10:50 am
07/17/94 83.88 | Crested...began falling 11:10 am

a li



APPENDIX D

FORECASTS ISSUED BY
SOUTHEAST RIVER FORECAST CENTER
BY FORECAST POINTS

Table D-1 shows selected forecast points on the major rivers/creeks throughout the southeastern
United States that were affected by heavy precipitation from Tropical Storm Alberto. The table
identifies (1) the river or creek; (2) the location of the forecast point; (3) the site identifier;
(4) the flood stage, in feet; (5) the date/time and stage of the forecast crest; (6) the issue
date/time of the forecast; and (7) the date/time and stage of the observed crest. Those sites that
had a flood of record are noted with an "*" in the observed crest.

Tables D-2 through D-22 represent the selected forecast(s) issued by the Southeast River
Forecast Center for each forecast point that was shown in Table D-1. The columns show (1) the
date of the forecast; (2) the latest observed stage at the forecast point, in feet, at the time of the
forecast; (3) the forecast, in feet, and river tendency; and (4) the time the forecast was issued.

Note:
cfs = cubic feet per second
Cr = crest
EDT = eastern daylight time
FS = flood stage
ft = feet
sIpD = site identification
TW = tall water of a dam

D-1


Eurek

Alaska

lew Orleans

amt
ry o
° Hawaii Puerto Rico | Legend ‘
J
Honolut Bs ~ «a @ Office Location ‘
5 —NHSA Boundary
—— State Boundary

Figure 2-8. Boundaries of hydrologic service areas of responsibility (the Melbourne office had
HSA responsibility rather than Miami as shown on map).

28


CHAPTER 3

ISSUES HIGHLIGHTED BY THE EVENT

3.1 TRANSITION/STAFFING/MODERNIZATION VULNERABILITIES

This event pointed to several aspects of the NWS modernization of its weather services where
the survey team felt the NWS was vulnerable, risking degradation of these services. These fall
into three general areas: (1) the transition to a modernized state, (2) staffing--both during
transition and after, and (3) several aspects of the NWS modernization and associated
restructuring.

3.1.1 TRANSITION

Two aspects of the transition to a modernized state clearly pose potential pitfalls for the NWS.
First and foremost is the amount of off-site training that is required during the transition.
Second is the increased length of the transition period resulting from budgetary constraints and
the inability of the NWS and its contractors to deliver significantly improved technology to its
field offices according to earlier projections.

The substantial requirement to train its work force often leaves field offices with staffing
situations that threaten their ability to efficiently perform their prime mission. Such was the case
in both NWSFOs and the RFC that were part of this survey. In each case, key personnel were
away from the office attending in-residence training courses for all or a portion of the event.
This, coupled with the fact the remaining staff at these offices included a notable number of
new, inexperienced people, posed a high potential for unacceptable service due to staff overload
during the disaster. This threat was averted in this event because of the extreme dedication and
extra effort of the personnel at the offices involved during the disaster. Nevertheless, the risk
is very real while the NWS undergoes a protracted transition period.

FINDING 3-1: Key members of the staffs of both NWSFOs and the RFC were
attending training away from their home offices during this event.

RECOMMENDATION 3-1: Especially during transition, when we have
extensive training requirements which are not a luxury, we must have adequate
staff to cover operations.

In addition to staffing concerns, the survey team found several potentially vulnerable aspects of
hardware configurations being implemented during the extended NWS transition period. While
the five WSR-88Ds accepted by the Government in this area were operational throughout the
event, use of the data from the radars was notably constrained. For instance, the SERFC had

41


RECOMMENDATION 3-9: The NWS must be more sophisticated in its use of
communication and dissemination technologies. For example, the NWS should
take advantage of aspects of the Information Superhighway (e.g., Internet) to
coordinate with the public and other Federal, state, and local agencies as much
as possible. Through increased electronic dissemination of NWS products, the
NWS staff’s time is more effectively used by allowing direct communication with
many more users/agencies. Additionally, users/agencies getting information
directly from the NWS can then further distribute it automatically without having
to repeat, dictate, or retype the information.

Another approach is to integrate into routine NWS field operations a range of
communications tools (e.g., satellite broadcast, packet radio, teleconferencing) in
order to match the ever-increasing technical capabilities of the NWS’ many
customers.

3.2.2 IMPROVED COORDINATION BETWEEN NWS AND FEMA

Upon arrival in the disaster area, FEMA quickly established elaborate satellite television
communications to continually broadcast important information to its personnel in the field, as
well as FEMA officials in Washington, D.C. Included in the string of information were updates
on current weather and flooding information.

FINDING 3-10: Agencies, like FEMA, have made and continue to make great
advances in their abilities to effectively communicate with their users; however,
the NWS is not fully utilizing the recent advances in information technologies.

RECOMMENDATION 3-10: NWS should create national capabilities that
parallel the capabilities of FEMA for special emergency response and disaster
relief operations. This should be coordinated by the regional or national NWS
offices, as appropriate for the magnitude of the event. For example, the NWS
should institutionalize the capability to provide support for satellite feeds
coordinated by FEMA which are then made available to other Federal and state
government agencies and locally on cable television.

A possible mechanism for such support would be one (or more) centrally located national media
center(s) that would have access to equipment (e.g., a communications uplink; large-screen video
monitors capable of depicting NEXRAD, AFOS, AWIPS data and products; etc.). In addition,
personnel would be available to be rapidly deployed to NWS offices involved in major
meteorological and/or hydrological events.


no way to directly input the WSR-88D precipitation estimates into its hydrologic models.
Additionally, none of the spin-down WSOs with county warning responsibility had any access
to WSR-88D data (other than what was verbally communicated secondhand or via text products).
Due to staffing limitations, one NWSFO and the SERFC chose not to dedicate someone to
monitor the WSR-88D throughout the event. Rather, they chose to make note of the WSR-88D
data on an ad hoc basis. These factors alone could have (but did not in this case) severely
limited the ability of the field offices to determine the magnitude of the event at the earliest
possible time.

FINDING 3-2: One NWSFO and the RFC affected by Alberto did not have
sufficient human resources, and the other NWSFO did not have sufficient
communications resources, to fully utilize data from the WSR-88Ds in the area.
None of the WSOs with warning responsibilities had any access to WSR-88D
data. In addition, the RFC was unable to process the precipitation data from the
WSR-88Ds so they could be input to the hydrologic models.

RECOMMENDATION 3-2: The NWS must recognize that during the transition
it is not able to fully utilize the WSR-88D and should continue to take steps to
accelerate other portions of the modernization and make maximum use of
technology components which are mature enough to warrant deployment.

There is another area where the NWS seems to be very vulnerable during transition and into
modernization: the amount of time available for the WCMs to coordinate with their present and
future emergency management (and other action agency) officials. Due to operational shift
workload requirements that result from staff shortages (because of training requirements),
WCMs often do not have adequate time available to coordinate with their users. The survey
team found this to be the case during its study.

FINDING 3-3: The operational shift and training requirements, coupled with a
large geographic area of responsibility, limited the opportunity for the WCMs to
interact with local users. Consequently, the WCMs did not thoroughly coordinate
with all the users in their CWA.

RECOMMENDATION 3-3: The NWS needs to develop an efficient strategy
to maximize the efficiency of the collective efforts of the WCMs and other staff
members. A WCM team approach should be considered whereby other WFO
(and occasionally RFC) staff members are designated as liaisons with the state
and local agencies involved in such activities as emergency management, water
resources, and public safety.

One aspect of current NWS operations, which becomes a greater problem during transition, is
the flow of information from NWS field offices in one state to emergency managers in an
adjoining state. Some local emergency managers with adequate funding and personnel resources
subscribe to NWWS and receive hard copies of NWS products. However, due to the large

42



Table D-2. Chattahoochee River at WF George L&D TW FOGGI, Flood Stage 134 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/06/94 133.74 | Crest near 146 7th 11:05 am
07/07/94 149.08 | Falling 12:45 pm
07/08/94 146.03 | Falling 12:15 pm
07/09/94 137.6 | Fall below FS 10th 12:25 pm
07/10/94 116.98 | Below FS and falling 11:25 am

Crest: 149.9 ft, 10 pm 7/06/94
Peak discharge: 123,000 cfs for few hours on 7/06/94
Previous Flood of Record: E158.5 ft, 3/17/29

D-4



Table D-12. Apalachicola River near Blountstown BLOF1, Flood Stage 15 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/04/94 8.0 | Crest near 19 7th 10:10 am
07/05/94 15.06 | Crest near 22 7th 10:50 am
07/06/94 18.9 | Crest near 24 9th 10:50 am
07/07/94 21.42 | Crest near 24 9th 12:40 pm
07/08/94 23.88 | Crest around 27 9th 12:45 pm
07/09/94 26.16 | Crest 27.5-28 10th 11:55 am
07/10/94 27.01 | Crest 27.5-28 tonight 11:55 am
07/11/94 27.25 | Crested..began slow fall 12:05 pm
07/12/94 25.6 | 24.5 24 23.5 23 22.5 11:45 am

Crest: 27.39 ft, pm 07/10/94
Previous Flood of Record: 28.6 ft, 3/21/29

D-14

\

~

ne ctl


2.3.3. THE BAINBRIDGE FORECAST

Forecasts were generally accurate and highly regarded with the notable exception of Bainbridge,
Georgia, where the Flint River was forecast to reach a level some 8 feet higher than its eventual
crest. This persistent overforecast was the subject of considerable negative attention by the
media and the public and has resulted in some loss of forecast credibility for the NWS.

The SERFC crest forecast for Bainbridge was raised during the first days of the event (prior to
July 7) due to additional heavy rainfall. Table 2-3 shows the crest forecast issued by SERFC
for Bainbridge July 7-13.

Table 2-3. Bainbridge crest forecast issued by SERFC July 7-13
a

Issue Date Forecast Crest/Date
117194 near 45 feet/July 13
718/94 near 45 feet/July 13
119/94 near 45 feet/July 13
7/10/94 near 45 feet/July 13
7/11/94 44-45 feet/July 14
7/12/94 43-44 feet/July 14
7/13/94 37-38 feet/July 14

The Flint River crested at Bainbridge July 14 at a stage of 37.20 feet. A discharge measurement
taken by the USGS shortly before the crest (while the stage was 37.18 feet) indicated a flow of
approximately 108,000 cfs. By comparison, the record flood of January 1925 reached a level
of 40.9 feet (from high water marks) with a flow of approximately 101,000 cfs.

Based on the forecast provided by the NWS, and seeing the record crests that were occurring
upstream, Bainbridge city officials determined the area that would be affected by the 45 foot
forecast crest and proceeded with their evacuation plans and flood protective measures. In the
end, only about half the evacuated area was flooded, causing much less damage than anticipated.
As a result, the credibility of the NWS river forecast for Bainbridge was indeed damaged and
needs to be restored.

There may be a variety of factors which led to the Bainbridge forecast error. It will not be a

part of this report to completely analyze the hydrology relating to the Bainbridge forecast.
Factors that may need further investigation include:

35


TABLE OF CONTENTS

Preface... ee eee teen eee v
Foreword 2.0.0... eee eee eee vii
Executive Summary 2... 2. eee eee eee ix
Acronyms and Abbreviations 2.0.2... 2 eee xiii
Chapter 1. Background and Overview of the Event.................. 1
1.1 Introduction ©... eee 1
1.2 Impact of the Flooding ©... ....... 0.0.0... 1
1.3. Hydrometeorological Analysis ...... 2
1.3.1 Storm Genesis and Landfall 3

1.3.2 Description of the Antecedent Conditions and
Heavy Precipitation... 2... 2... 3
1.3.3 Description of the Flooding ....................0004. 4
Chapter 2. | Overview of NWS Performance ..................20.00000. 11
2.1 Storm Prediction... 2... eee 11
2.1.1 Summary of Storm Track and Forecasts ................ 11

2.1.2 Evaluation of NMC Numerical Guidance and
Storm Track Forecasts ..........0.0.0. 0.0.00 00000 0005 12
2.1.3. Summary of Quantitative Precipitation Forecasts ........... 14

2.1.4 Day-by-day Comparison of Numerical Guidance

and Manually Issued Forecasts ...................0.. 19
2.2 Precipitation... 2... eee 21
2.2.1 NEXRAD WSR-88D .......... 000000: c cece eee 21
2.2.2 Locally Acquired Data... 1... 2. eee 25
2.2.3 Central Data Systems and RFC Processing ............... 26
2.2.4 Data Exchange with Cooperating Agencies ............... 27
2.3 Flood Forecasting Service ©... 2.2.2... ee eee 27
2.3.1 Flash Flooding ..... 2.2.2... 0000... 00 0000000000008 27
2.3.2 River Flooding ... 20.0... 0.0... cee eee 32
2.3.3 The Bainbridge Forecast. ............000000000000008 35
2.4 Preparedness 2.2... eee eee 36
2.5 Dissemination... 2... eee 39

iii



[mi?, square miles; ft, feet above an arbitrary datum; ft?/s, cubic feet per second; *, new peak of record; a, approximately; d, discharge may have been affected by dam break; --, not
determined or not applicable; <, less than; >, greater than; number in () is the ratio of the peak discharge to the 100-year flood discharge. Source: Recurrence intervals calculated
from U.S. Geological Survey data through 1990 water year. Other data from U.S. Geological Survey reports or data bases]

Maximum prior to July 1994 Maximum in July 1994
Discharge
Drain- recurrence
USGS station age area Period of Discharge Stage Discharge interval
number Stream and place of determination (mi) record Year Stage (ft) —_(ft?/s) Day (ft) (£0 /s) (years)

CHATTAHOOCHEE RIVER BASIN

02337500 Snake Creek near Whitesburg, Ga 35.5 1955-94 1961 14.40 7690 4 3.83 455 2
02338660 New River near Corinth, Ga 127 1979-94 1990 17.17 10,000 6 11.29 3,470 3
02341500 Chattahoochee River at Columbus, Ga 4,670 1841, 86,1913,

16, 1920-94 1929 55.20 198,000 7 31.24 69,000 Regulated
02342500 Uchee Creek near Fort Mitchell, Al 322 1947-94 1964 26.45 55,100 8 23.35 25,600 25

© 02342933 South Fork Cowikee Creek near Batesville, Al 112 1964-94 1990 43.40 28,200 4 31.17 13,200 30
02343244 — Cemochechobee Creek near Coleman, Ga 15.3 1984-94 1984 7.46 965 4 «11.84 *5,160 >100 (2.7)
02343267 Temple Creek near Blakely, Ga 2.78 1978-94 1978 2.59 0 6 © 6.13 *746 >100 (1.2)
02343300 Abbie Creek near Haleburg, Al 146 1958-94 1970 23.84 7,590 6 37.00 *35,000 >100 .5)
02343801 Chattahoochee River at Andrews Lock & Dam, Ga 8,210 1975-94 1990 123.29 195,000 7 123.98 202,000 Regulated
FLINT RIVER BASIN

02344300 Camp Creek near Fayetteville, Ga 17.2 1961-73, 94 1961 9.90 2,800 5 13.89 *6,300 >100 (1.6)
02344350 Flint River near Lovejoy, Ga 130 1986.94 1990 17.76 8,090 5 23.60 *19,000 >100 (1.2)
02344500 Flint River near Griffin, Ga 272 1929, 37-94 1929 17.90 15,300 6 24.22 *31,500 >100 (1.9)
02344700 Line Creek near Senoia, Ga 101 1965-94 1977 14.88 9580 5 201 *28,400 >100 (2.4)
02346180 Flint River near Thomaston, Ga 1,220 1900-29, 39-

50, 1952-56,

61, 64-94 19290 62,000 6 21.83 55,000 100

02346195 Lazer Creek near Talbotton, Ga 81.3 1981-94 1990 24.10 36,100 6 16.17 19,600 >100 (1.7)



number of nonoperational shifts for each meteorologist to be trained to handle
hydrologic crises at all times. In addition, MICs should adhere to the guidance
that SHs work no more than 20 percent of their time on forecast shifts.

The consolidation of WSFOs and WSOs into the future WFOs (currently 300+ offices down to
115+ offices) poses significant problems for the present-day and future WCMs. These problems
include (1) the number of counties in their areas of responsibility, (2) the geographic size of the
CWA, (3) the number of responsible county and local officials, (4) the geographic distance
between them and the WFOs, and (5) that the CWA may include multiple states.

FINDING 3-8: The personal contacts between the local EMA officials and WSO
staffs contributed to their satisfaction with the NWS services. When these offices
spin down, the responsibility switches to a single WCM.

RECOMMENDATION 3-8: A WCM team approach should be considered with
other WFO staff members (e.g., the SH) interacting with the customers.

3.2 EMERGING CHALLENGES
3.2.1 EXPANDING THE USE OF IMPROVED COMMUNICATION TECHNOLOGY

New demands for information are placed on the NWS due to increasing and changing societal
vulnerability to weather, growing awareness of this vulnerability, and technological advances,
especially in computing and communications. These demands, and the changes brought about
by the ongoing NWS restructuring, continue to impact and influence both the current operations
and planning for future operations of the NWS.

In this event, as is typical in current NWS operations, at least a portion of the dissemination of
forecasts and services was conducted over the telephone, one-on-one with users/customers. The
primary methods of dissemination continue to be the NWWS and the NWR. Many customers
place a high value on the personalized service provided by phone contact, and it contributes
greatly to the perception of high-quality services provided by the NWS. One challenge of the
modernized NWS will be to continue, and to increase, the level of service and customer
satisfaction with that service while decreasing the number of individual contacts required.

FINDING 3-9: One-on-one phone contacts between the NWS and all types of
users are frequently associated with the user’s satisfaction with the service
provided by the NWS. However, the number of individual phone calls which can
and should be made is limited. An additional drawback for the users who rely
on phone contacts is that they have to verbally repeat, dictate, or retype (or some
combination) the information in order for it to be shared.

45


TEAM 2 CONTACTS:

National Weather Service Offices:

WSFO Birmingham (AL):

WSO Montgomery (AL):
WSO Pensacola (FL):

National Hurricane Center (FL):

National Meteorological Center:

Emergency Management Agencies (EMA):

Alabama State Emergency
Operations Center and FEMA:
Houston County (AL) EMA:
Columbia (AL):

Holmes Cow EMA:

MEDIA (Atlanta, GA):
The Weather Channel:
CNN:

Channel 5:

Gary Petti, Meteorologist in Charge;
Brian Peters, Warning and Coordination
Meteorologist; and Roger McNeil, Service
Hydrologist

Wade Hilton, Officer in Charge

Frank Rieser, Acting Officer in Charge;
Dan Rice

Bob Sheets

NMC3x1 Robert G. Derouin, Meteorological
Operations Division

Eddy Hamby, Dave Poundstone, and
J.C. Davenport, Disaster Field Office,
Montgomery

Bobby Clemons, Dothan

James Greene, Mayor

Wanda Cunningham, Bonifay

Ken May

Jeff Wilhelm

Ken Cook

E-3


(@) ()

Figure 2-5. QPF graphics for 24 hours ending 1200 UTC July 7, 1994: (a) observed,
(6) manual forecast, (c) ETA forecast, (d) RAFS forecast, and (e) AVN forecast.

18


Since the synoptic pattern had little or no forcing and weak steering currents, the NMC models
generally did not perform well with regard to the track of the storm, especially after the storm
made landfall. In addition to difficulty in forecasting storm track, current numerical models do
not typically perform well forecasting precipitation amounts associated with tropical systems.
Beginning Tuesday, July 5, the models began to diverge with respect to the forecast track of the
remnants of Alberto. The Eta model consistently produced the preferred (and best, as it turned
out) forecast of storm movement and QPFs throughout the event.

The model forecasts were good for the first two days of the event, Sunday, July 3, and Monday,
July 4. However, after this time, only the Eta model performed well. Although the Eta model
at times had a tendency to take the remains of Alberto a little too far north, it offered the most
reliable numerical model guidance. From Tuesday, July 5, through Thursday, July 7, the RAFS
model was incorrectly trying to shear the remnants of Alberto out to the northeast, while the
AVN model would continually dissipate the system beyond its 24-hour forecast. Thus, much
of the manual guidance issued by the WFB was based on the Eta model.

FINDING 2-1: As is generally the case with a synoptic pattern with little or no
forcing and weak steering currents, the NMC and NHC models in general did not
perform well with regard to the track of the remnants of Tropical Storm Alberto.

RECOMMENDATION 2-1: The NWS should continue to strive for
improvements in tracking tropical systems once they make landfall. It is
especially important that improvements be made in the forecasts at the surface and
not just in the mid and upper levels of the atmosphere. Interactions with the
research community within NOAA (such as the Office of Atmospheric Research)
and other Federal agencies, as well as the academic research community, are
especially encouraged.

2.1.3 SUMMARY OF QUANTITATIVE PRECIPITATION FORECASTS

Forecast discussions issued by the forecasters in the WFB between July 4 and July 7 highlighted
the strong possibility for flooding and extremely heavy rain. A discussion issued very early
Monday morning, July 4, highlighted a "Very dangerous Flash Flood and Flood situation for
much of Georgia today into tonight as the remnants of Alberto drift slowly north." This same
discussion mentioned isolated rains of greater than 5 inches between Monday morning and
Tuesday morning. On Tuesday afternoon, July 5, an excessive rainfall discussion was issued
which indicated that 5-8 inches of rain was a good possibility Tuesday night over a large portion
of northern and central Georgia into eastern Alabama. On Wednesday, July 6, an excessive
rainfall discussion began with "A dangerous and almost unbelievable situation remains over
Georgia and is expected to spread into eastern Alabama, with additional rainfall amounts of 5
to 8 inches possible across southwestern Georgia into southeastern Alabama."

Manual QPFs issued by the WFB were better than the QPFs generated by the models. QPF
graphic forecasts for July 4, 5, 6, and 7 are included as Figures 2-2, 2-3, 2-4, and 2-5,

14



from Plains, Georgia, was unable to call in his observation due to repeatedly busy phones at
NWSFO Atlanta. All spotters and cooperative observers share one phone line which is not
dedicated to those functions. The Meteorologist in Charge (MIC) at Atlanta said additional
phone lines would have been helpful. NWSFO Birmingham had some problems getting people
to the gages to take observations and also with backup observers adding the height above mean
sea level to their gage readings. The NWSFO Birmingham frequently called their cooperative
observers to obtain data. Both the Atlanta and Birmingham NWSFOs called the Limited
Automatic Remote Collector (LARC) gages themselves and routinely got 6-hour data (or more
frequently, as needed).

FINDING 2-8: A limitation in the number of phone lines caused problems for
at least one office and a cooperative observer from a critical area who was not
able to provide data to the NWS because of busy phone lines.

RECOMMENDATION 2-8: Ensure that data are not lost due to inadequate
phone lines into NWS offices and have adequate automated collection systems to
acquire data so that the capacity of voice lines is not a constraint.

2.2.3. CENTRAL DATA SYSTEMS AND RFC PROCESSING

The SERFC gets centrally decoded data and makes its model runs on the NOAA Central
Computer Facility (NCCF) via a Remote Job Entry (RJE) system. There were no problems with
the central data systems, and model run performance on the NCCF was good. When the
dedicated RJE communications were down for 3-4 hours, the dial backup feature did not work
because the dial backup phone line was not reattached to the RJE system after the office moved
in April 19, 1994. The SERFC staff later successfully tested the dial backup by sharing the fax
line.

FINDING 2-9: The RJE dial backup did not function because the dedicated
phone line had not been connected to the system. The RJE dial backup had not
been tested since the office moved.

RECOMMENDATION 2-9: REC staffs must routinely test the RJE dial backup.

The RFCs running on the NCCF have the ability to declare a Critical Flood Situation which
allows them to use the crisis job priority, increases the priority of the central data acquisition
systems, and may limit the preventative maintenance that is done on the NCCF.

FINDING 2-10: The SERFC did not declare a Critical Flood Situation during
the Alberto event, because job processing times were adequate.

RECOMMENDATION 2-10: The declaration of a Critical Flood Situation and
use of the crisis job priority are powerful tools that should be utilized by the
RFCs during any critical flood event.



FINDING 2-13: The Sheriff of Sumter County, Georgia, had high praise for NWS products
and service during this event and did not think there was anything the NWS could have done to
reduce the loss of life during this event. He did think it is a mistake for the NWS and the media
to emphasize tropical storms only up until landfall; and then, in some cases, the public perceives
that there is no danger because of a relatively weak wind-producing storm.

RECOMMENDATION 2-13: The NWS should work with the media to educate the public on
the fact that heavy rains and widespread flooding from tropical storms and hurricanes may have
as much, and in some cases even more, detrimental impact as winds at landfall.

FINDING 2-14: The disaster survey team found that the Flash Flood Warnings issued in this
event were generally accurate and timely. However, many lacked a strong enough indication
of the life-threatening nature of the flash flooding.

RECOMMENDATION 2-14: NWS offices should strive to better recognize truly extreme
rainfall events and, in those events, use the strongest possible wording in the warnings and
statements issued to make the public more cognizant of the life-threatening nature of the event.

FINDING 2-15: The disaster survey team found a high degree of satisfaction from emergency
managers, the media, and the public with the river forecast services they received during this
event. In particular, the impact statements and relationship to recent and historical flood levels
were judged valuable information.

RECOMMENDATION 2-15: NWS Hydrologic Service Area offices should make every effort
to include up-to-date and informative impact statements in all Flood Warnings and Flood
Statements.

FINDING 2-16: There were several suggestions from emergency managers and the media that
the public river forecasts be updated more frequently. The normal procedure presently is to
issue the Flood Statements once per day in late morning or early afternoon. In particular, an
early morning update was suggested to provide current information so the public can make more
informed decisions on commute, daily activities, or evacuation activities.

RECOMMENDATION 2-16: NWS offices should make every attempt to update Flood
Warnings and Flood Statements more than once per day.

FINDING 2-17: Several users suggested that changes in crest forecast values be highlighted at
the beginning of Flood Statements. An analysis by the disaster survey team of the Flood
Statements issued during this event where the crest forecast was revised from the previous

A-4


Table D-1. Forecasts issued and observed crests at forecast points

River/Creek Station SID FS Forecast Issue Observed
Crest Date Crest
Chattahoochee | WF George TW | FOGG1 | 134 | Cr 146 ft 11:05 am | 149.9 ft
on 7th 7106/94 7106/94
Chattahoochee | Columbia TW COLAL | 113 | Cr 119-120 11:05 am | 123.98 ft*
ft on 7th 7106/94 1TI94
Flint Culloden CLUGI1 18 | Cr39 ft 10:35 am | 45.73 ft*
on 6th 7105/94 7106/94
Flint Montezuma MNTG1 | 20 | Cr 36 ft 12:45 pm | 34.11 ft*
on 8th 7107194 7108/94
Kinchafoonee | Preston PRSG1 7 Cr 10 ft 11:05 am | 11.66 ft
on 6th 7106/94 7106/94
Kinchafoonee | Dawson DSNG1 13 Cr 30 ft 12:45 pm | 26.56 ft*
on 9th TI07/194 7107/94
Flint Albany ABNG1 20 | Cr 45-46 ft 11:25 am | 43.0 ft*
on 10th pm =| 7/10/94 TNL94
Flint Newton NEWG1 | 24 | Cr 45-46 ft 11:15 am | 45.25 ft*
on 12thpm =| 7/12/94 7/13/94
Flint Bainbridge BGEG1 25 Cr 37-38 ft 11:45 am = | 37.20 ft*
on 14th 7113/94 7/14/94
Apalachicola | Woodruff TW WDRF1 | 66 | Cr 77-78 ft 11:55 am | 76.29 ft*
on 9th pm 7109/94 7/10/94
Apalachicola | Blountstown BLOF1 15 | Cr 27.5-28 ft | 11:55 am | 27.39 ft
on 10th pm =| 7/09/94 7/10/94
Chipola Marianna MALF1 19 Cr 25 ft 11:55 am | 24.0 ft
on 9th pm 7109194 7110/94
Chipola Altha ALTF1 22 ~=‘| Cr 30-31 ft 12:05 pm | 29.60 ft
on 12thpm =| 7/11/94 712/94
D-2

et a le a Hl



By following the Eta solution, the 24-hour QPF issued by the WFB on Tuesday morning and
ending at 1200 UTC Wednesday, July 6, hit central Georgia the hardest, with up to 5 inches of
rain forecast. Subsequent shorter-range forecasts issued later Tuesday afternoon and verified
Wednesday morning increased the rainfall potential. The excessive rainfall discussion issued at
2:50 p.m. EDT Tuesday, July 5, mentioned a "good possibility of 5-8 inch rains" by Wednesday
morning for a large part of central and northern Georgia and eastern Alabama. The observed
24-hour precipitation ending at 1200 UTC Wednesday, July 6, showed the manual forecast was
underforecast and a little too far north. Several stations in central and southwest Georgia
received in excess of 10 inches of rain during this period.

QPFs produced by the models were generally less accurate than the manual forecasts for the
verifying period from Tuesday through Wednesday morning, especially the RAFS and AVN.
The Eta model was the best of the models, forecasting a little more than 3 inches of rain for
southern Alabama.

By Tuesday night, July 5, it became increasingly apparent from upper air data that Alberto likely
would be blocked from moving any farther north. The upper-level analyses from 0000 UTC
Wednesday, July 6, indicated that a ridge was building north of the system from the Tennessee
Valley eastward through the central Appalachians. This building ridge would essentially put a
halt to any further northward progression. In addition, on Tuesday evening, satellite pictures
showed Alberto had stopped moving north and could even be drifting very slowly
southwestward.

Unfortunately, the numerical models couldn’t agree again on where the system was going. The
Eta model kept the system stationary in northern Georgia. The RAFS again sheared the system
out too quickly into the Appalachians, and the AVN "lost" the feature after about 24 hours.
Knowing that the Eta model had been superior in handling this storm throughout the event, and
seeing what was developing synoptically, WFB forecasters again adopted the Eta solution. The
excessive rainfall discussion issued very early Wednesday morning, July 6, correctly noted that
"The actual center has been forced a little southward during the past 24 hours by ridging to the
north and by far the Eta model has been superior in handling this system. Believe the system
could continue moving slowly southward for a while longer before becoming stationary later
today. Additional rains of 5 to 8 inches are possible over southwestern Georgia and southeastern
Alabama."

The 24-hour manual QPF issued around 1000 UTC Wednesday morning, July 6, valid
1200 UTC on Thursday, July 7, had more than 5 inches of rain occurring over a large part of
southeastern Alabama and a smaller portion of southwestern Georgia and more than 3 inches of
rain for much of southwestern Georgia, the southern half of Alabama, and most of the Florida
Panhandle. These amounts turned out to be underforecasted and displaced a little too far north
and east. The observed rains, ending at 1200 UTC Thursday, July 7, showed maximum
amounts greater than 10 inches over the Florida Panhandle, with much of the Panhandle and
southeastern Alabama receiving more than 5 inches.

20

cans —* ca: dsm mathe, <<” sie sings lames aripammttaatmmmcmaes


Table D-18. Ocmuigee at Lumber City LBRGI, Flood Stage 15 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
, | 07/06/94 5.0 | Crest near 25 16th 11:05 am
07/07/94 5.17 | Crest near 25 16th 12:45 pm
07/08/94 5.37 | Crest 27-28 16th 12:15 pm
07/09/94 5.73 | Crest 27-28 15th 12:25 pm |
07/10/94 6.32 | Crest 27-28 15th 11:25 am
| 07/11/94 7.31 | Crest 26-27 15th 11:55 am
07/12/94 10.93 | Crest near 26 15th 11:15 am |
Ee 19.96 | Crest near 26 15th 11:45 am |
| 07/14/94 24.04 | Crest near 26 15th early 11:50 am. |
07/15/94 24.51 | Near crest 25-26...begin falling today | 11:40 am |
07/15/94 24.43 | Crested...began slow fall 1:10 pm
07/16/94 23.47 | Fall below FS 21st 10:50 am

Crest: E24.59 ft, 2:38 am 07/15/94

Previous Flood of Record: 26.3 ft, 1/21/25

USGS Measurements: 22.63 ft = 77,300 cfs, 6:30 pm 7/13/94
24.20 ft = 85,900 cfs, 11 am 7/14/94

D-20


CHAPTER 1

BACKGROUND AND OVERVIEW OF THE EVENT

1.1 INTRODUCTION

A decaying tropical system, previously known as Tropical Storm Alberto, produced torrential
rainfall which resulted in some of the worst flooding ever observed across portions of the
States of Georgia, Alabama, and Florida during July 1994. Alberto, the 1994 Atlantic
Hurricane Season’s! first named tropical system, came ashore near the Florida Panhandle
town of Destin at about 1500 Universal Coordinated Time (UTC) on July 3. The winds
associated with the tropical storm caused only minor damage and no casualties, as maximum
sustained winds of around 65 mph (55 knots) were briefly observed at the time of landfall.
The highest storm surge was estimated at 5 feet near the point of landfall (Destin, Florida).
No reports of tornadoes were confirmed in association with Alberto or its remnants.

As the tropical storm’s winds rapidly diminished, attention was quickly and appropriately
turned to the threat of heavy rainfall associated with the deep tropical moisture being
transported by the remnants of Alberto. Indeed, over the course of the 4 days following
landfall, the forward motion of the remnants of Alberto slowed and halted, only to loop back
over the same area already traversed before finally dissipating. It was this meandering
motion which resulted in record-breaking rainfall, including a storm total of over 27 inches
at Americus, Georgia, more than 21 inches of which fell in a 24-hour period. The torrential
rainfall led to exceptional flooding across central and western Georgia, southeastern
Alabama, and the Florida Panhandle. Five river basins were particularly hard hit (see
Figure 1-1): (1) the Flint River Basin in western Georgia, (2) the Ocmulgee River Basin in
central Georgia, (3) the Chattahoochee River Basin along the Georgia-Alabama state line,
(4) the Choctawhatchee River Basin in Alabama, and (5) the Apalachicola River Basin in
Florida.

1.2. IMPACT OF THE FLOODING

Figure 1-2 shows the counties that were Presidentially declared disaster areas. Most of the
declared counties were concentrated along the five rivers (and their tributaries) mentioned in
the section above. A total of 78 counties were declared Federal disaster areas, including
55 in Georgia, 10 in Alabama, and 13 in Florida.

"Hurricane Season is defined as the period each year from June 1 through November 30.

1


. .
River/Creek Station SID FS Forecast Issue Observed
Crest Date Crest
Ocmulgee Macon MACG1 18 Cr 35 ft 5:00 pm 35.4 ft*
on 7th 7106/94 7107194
Ocmulgee Hawkinsville HAWGI1 | 25 Cr 43-44 ft 12:25 pm_ | 40.91 ft*
on 10th 7109/94 7109/94
Ocmulgee Abbeville ABBG1 12 Cr 23 ft 11:25 am | 23.1 ft®
on 1ith 7/10/94 TI1/94
Ocmulgee Lumber City LBRG1 15 Cr 26 ft 11:15 am = | 24.59 ft
on 15th 7/2194 TINS/94
Altamaha Charlotte CHRG1 15 Cr 24 ft 11:15 am =| 23.3 ft
on 16th 72/94 7/16/94
Altamaha Baxley BAXG1 | 74.5 | Cr 84-85 ft 11:45 am | 84.1 ft
on 17th 7/13/94 7/16/94
Altamaha Doctortown DCTG1 14 Cr 14-15 ft 11:45 am =| 14.57 ft
on 18th 7/13/94 7/19/94
Oconee Penfield PNFG1 11 Cr 13 ft 11:05 am _ | 12.10 ft
on 7th 7113/94 7106/94

* Indicates flood of record level



a NTR mr me rm mm ae a a

Te

Table D-7. Kinchafoonee Creek near Dawson DSNGI, Flood Stage 13 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/04/94 4.9 | Crest near 13 8th 10:15 am
07/04/94 9.6 | Crest near 14 6th 9:45 pm
07/05/94 14.4 | Crest 18-19 8th 10:35 am
07/05/94 16.5 | Crest 20-21 7th 3:00 pm
07/06/94 18.5 | Crest 20-21 7th 11:05 am
07/06/94 23.9 | Crest near 25 10th 10:10 pm
07/07/94 26.42 | Crest near 30 9th 12:45 pm
[Lov/o8/04 23.88 | Falling below FS 11th 12:15 pm

Crest: 26.56 ft, 2 am 7/7/94
New record level
Previous Flood of Record: 20.4 ft, 3/20/90

D-9


Many of the deaths in this event can be attributed to individual lack of judgment: refusal to
evacuate despite the request of emergency managers and other authorities, attempts to either
drive around barricades or on inundated roads, and other actions obviously inappropriate in
the face of the hazard. Approximately two-thirds of the deaths were related to vehicular
incidents. They also represent a small fraction (less than 0.1 percent) of the total number of
people evacuated. Nevertheless, the high loss of life is troubling and clearly leaves room for
improvement. A few people were seemingly unaware of the impacts of their weather-related
decisions. Some complacency was evident early in the event. A factor which may have
contributed to this complacency is the fact that recent floods in the Southeast have not been
nearly as severe as this one. Therefore, most residents did not have previous experience in
dealing with such a dangerous flood event.

Although general external impressions of NWS performance were favorable, the disaster
survey team’s closer examination revealed a number of causes for concern and opportunities
for improvement (a summary of all the findings and recommendations of the disaster survey
team is located in Appendix A):

- Perhaps as much as any single factor, the inability of NWS centralized
model guidance to predict the reversal of the storm motion and
precipitation amounts significantly limits the utility of NWS products
and services. The NWS should work with the Office of Atmospheric
Research and other Federal agencies, as well as the academic research
community, to improve such predictions.

- The forecast for the Flint River at Bainbridge received considerable
media and public attention when the river crested well below the
forecasted level. The forecast at Bainbridge needs to be investigated
and appropriate changes made to the forecast scheme.

- There is some indication that a number of problems occurred during the
event that were related to the public’s perception of the interfaces
between responsibilities. Examples of these interfaces include the
following: between the National Hurricane Center and National
Meteorological Center’s Meteorological Operations Division as the
storm made landfall; between Weather Service Forecast Offices;
between Weather Service Forecast Offices and Weather Service
Offices; between Weather Service Forecast Offices and the River
Forecast Center; and between the NWS and the media, emergency
managers, and the general public. Interfaces are inevitable.
Modernization in the NWS will cause a shift in a number of them. The
NWS should develop an inventory of particularly important interfaces
and ensure that the treatment of these receive special attention and

priority.



——

Table D-5. Flint River at Montezuma MNTGI, Flood Stage 20 ft

Date Latest Forecast (ft) | Issue Time (EDT) |
Report (ft)
07/05/94 4.6 | Crest near 27 8th 10:35 am
07/05/94 7.13 | Crest near 30 8th 3:30 pm
07/06/94 18.4 | Crest near 30 8th 11:05 am
07/07/94 30.2 | Crest near 33 8th 4:45 am
07/07/94 E34.0 | Crest near 36 8th 12:45 pm
07/08/94 35.0 | Crest near 36 today 12:15 pm
07/09/94 Crested...falling below FS 14th 12:25 pm

Crest: E35 ft, about noon 7/08/94
New record level

Previous Flood of Record: 27.4 ft, 3/17/29
USGS Measurements: 34.1 ft = 134,000 cfs, 3 pm 7/07/94

D-7


Table D-16. Ocmulgee River at Hawkinsville HAWGI, Flood Stage 25 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)

07/05/94 7.1 | Crest near 17 12th 10:35 am
07/05/94 Crest near 28 11th 3:30 pm

07/06/94 10.1 } Crest near 37 11th 11:05 am
07/07/94 21.4 | Crest near 37 11th 12:45 pm
07/08/94 31.0 | Crest near 41 11th 12:30 am
07/08/94 35.43 | Crest 41-42 11th 12:15 pm
07/09/94 40.73 | Crest 43-44 10th 12:25 pm
07/10/94 39.76 | Crested...now falling 11:25 am

Crest: 40.91 ft, 1 to 2 pm 7/09/94, High water mark
New record level

Previous Flood of Record: 36.5 ft, 1/21/25

USGS Measurement: 39.8 ft = 87,900 cfs, 7/10/94

D-18

a aa On ener

ee ee ee a Se re


flood-prone areas (particularly roads), safe evacuation routes, and the potential impact of their
actions.

RECOMMENDATION 2-21: If funding permits, the NWS, in conjunction with FEMA and
appropriate state and local agencies, should embark upon a campaign to educate the public as
to their local flood-prone areas. This should include a widely distributed array of visual
tepresentations of flood-prone areas depicting roads and bridges as well as portions of
communities that may be potentially inundated by floods. Additionally, the NWS should plan
to issue graphical flood forecasts as well as the traditional text products.

FINDING 2-22: The disaster team felt it was inappropriate for a single NWS office to be
expected to respond to an event that covered multiple offices and to FEMA’s national-level press
and Federal coordination briefings. In addition, there was an imbalance in the media contacts
and interest with the National Hurricane Center prior to landfall and Weather Forecast Branch
once the tropical cyclone had made landfall.

RECOMMENDATION 2-22: The NWS should establish a national media unit to provide
beginning-to-end coverage of storm events that have national impact or interest. This unit would
provide a consistent posture in front of the national media, which could emphasize the dangers
associated with each phase of the storm. The unit would be headed by a public affairs specialist
and supported by an ad hoc team of meteorologists and hydrologists, as appropriate for the
event. Teleconferencing should be utilized to maximize participation of personnel from a variety
of NWS offices.

CHAPTER 3: ISSUES HIGHLIGHTED BY THE EVENT

FINDING 3-1: Key members of the staffs of both NWSFOs and the RFC were attending
training away from their home offices during this event.

RECOMMENDATION 3-1: Especially during transition, when we have extensive training
requirements which are not a luxury, we must have adequate staff to cover operations.

FINDING 3-2: One NWSFO and the RFC affected by Alberto did not have sufficient human
resources, and the other NWSFO did not have sufficient communications resources, to fully
utilize data from the WSR-88Ds in the area. None of the Weather Service Offices (WSO) with
warning responsibilities had any access to WSR-88D data. In addition, the RFC was unable to
process the precipitation data from the WSR-88Ds so they could be input to the hydrologic
models.

RECOMMENDATION 3-2: The NWS must recognize that during the transition it is not able
to fully utilize the WSR-88D and should continue to take steps to accelerate other portions of

A-6


FINDING 2-4: The number of automated rain gages under the umbrellas of many of the
WSR-88Ds in the area affected by Alberto was inadequate to effectively incorporate rain gage
data into the Stage I Precipitation Processing.

RECOMMENDATION 2-4: The rain gage data network must be expanded and the reporting
characteristics of existing sites modified to provide more timely data to produce a higher quality
WSR-88D precipitation estimate.

FINDING 2-5: Even though the Southeast River Forecast Center (SERFC) area of
responsibility has almost complete WSR-88D coverage, the SERFC was not able to
quantitatively use the WSR-88D information in its forecasts. The capability to process
WSR-88D digital precipitation estimates would have added value to the hydrologic forecasts.

RECOMMENDATION 2-5: Pre-AWIPS workstations must be deployed immediately to the
SERFC and other River Forecast Centers (RFC) so the Stages II and III Precipitation Processing
can be performed and utilized in the forecasts.

FINDING 2-6: The Atlanta WSR-88D was not able to retrieve data from the archive for a
precipitation event that set historical records.

RECOMMENDATION 2-6: The potential for losing data, for all time, that could be used for
storm analysis, training, and calibration of hydrometeorologic models and calibration of the
WSR-88D dictates a requirement that there be a prompt resolution of the problems with the
archive media.

FINDING 2-7: The WSR-88D was unable to provide all the products in the time required when
there was a large-scale precipitation event.

RECOMMENDATION 2-7: Develop methods to increase the number of products that can be
obtained by associated principle user processors, especially for offices with warning
responsibilities.

FINDING 2-8: A limitation in the number of phone lines caused problems for at least one
office and a cooperative observer from a critical area who was not able to provide data to the
NWS because of busy phone lines.

RECOMMENDATION 2-8: Ensure that data are not lost due to inadequate phone lines into
NWS offices and have adequate automated collection systems to acquire data so that the capacity
of voice lines is not a constraint.


Georgia

Alabama

Florida

>

gn
TRACK OF ALBERTO =
Miles
0 20 40
X

Figure 1-5. Composite showing Alberto’s inland track (dashed line), the 8-inch isohyet, the
78 counties declared Federal disaster areas (shaded), and the five major river systems.

10


2.5

An area that the NWS clearly needs to improve is its national-level response to disasters.
FEMA has improved the timeliness and magnitude of its disaster response. During a disaster,
FEMA is able to quickly establish a television communications link to the affected communities
as well as to key Federal officials in Washington, D.C., and other areas across the Nation. The
NWS must be prepared to participate in or establish similar radio and satellite communication

FINDING 2-21: The disaster team believes another possible contributing factor
to the high death count could be that the public was not adequately educated
regarding the locations of flood-prone areas (particularly roads), safe evacuation
routes, and the potential impact of their actions.

RECOMMENDATION 2-21: If funding permits, the NWS, in conjunction with
FEMA and appropriate state and local agencies, should embark upon a campaign
to educate the public as to their local flood-prone areas. This should include a
widely distributed array of visual representations of flood-prone areas depicting
roads and bridges as well as portions of communities that may be potentially
inundated by floods. Additionally, the NWS should plan to issue graphical flood
forecasts as well as the traditional text products.

DISSEMINATION

links and be a part of the information superhighway.

The media showed tremendous interest in broadcasting from the NHC before and during landfall
of Alberto. The NHC Director (or representative) was prominently featured on the broadcasts,
which heightened the sense of urgency. Once the storm was inland, however, there was much
less attention by the media and no single spokesperson from the NWS focusing attention on

continued potential from weather hazards.

FINDING 2-22: The disaster team felt it was inappropriate for a single NWS
office to be expected to respond to an event that covered multiple offices and to
FEMA’s national-level press and Federal coordination briefings. In addition,
there was an imbalance in the media contacts and interest with NHC prior to
landfall and WFB once the tropical cyclone had made landfall.

RECOMMENDATION 2-22: The NWS should establish a national media unit
to provide beginning-to-end coverage of storm events that have national impact
or interest. This unit would provide a consistent posture in front of the national
media, which could emphasize the dangers associated with each phase of the
storm. The unit would be headed by a public affairs specialist and supported by
an ad hoc team of meteorologists and hydrologists, as appropriate for the event.
Teleconferencing should be utilized to maximize participation of personnel from
a variety of NWS offices.

39


FINDING 3-5: The NWS offices affected by Alberto were stressed to provide
enough human resources during the disaster to continuously utilize all information
the WSR-88Ds had to offer. It would have been virtually impossible for these
offices to have provided the critical services they did if they were staffed with any
less employees.

RECOMMENDATION 3-5: The NWS should reassess its core-level staffing
requirements (going from five lead forecasters and five journeyman forecasters
down to four lead forecasters and four journeyman forecasters), especially for
offices with multiple WSR-88Ds.

3.1.3 MODERNIZATION

An area of vulnerability was the amount of time that Service Hydrologists (SH) have to develop,
transfer, and maintain a high level of hydrologic expertise at current and future NWS offices.
The survey team found that there are situations where the SHs were unable to adequately address
some of the following duties: (1) hydrologic training of on-site and off-site personnel,
(2) frequent and regular coordination visits to all county-level management in their present and
future CWAs, (3) station information (i.e., E-19) data collection activities, (4) personal
professional development (hydrologic and meteorological), and (5) frequent and regular visits
to the RFC to keep current on RFC operations.

The size of the present and future hydrologic service areas and hydrologic program training and
development responsibilities of each SH are so extensive that the SHs may not be able to fully
address important hydrologic program management functions and services.

FINDING 3-6: The SH workload at the offices surveyed was quite extensive and
typical of any WFO. Despite the good effort put forth by the SHs, it was
apparent that timely completion of important hydrology-related duties could not
always be accomplished. This will be compounded in the future for SHs who
support multiple hydrologic service areas.

RECOMMENDATION 3-6: The NWS should reassess its staffing philosophy
for field offices; each WFO should have a resident SH.

FINDING 3-7: Staffing levels at the NWSFOs surveyed by the team, coupled
with operational workloads and off-station training requirements, made it virtually
impossible for a sufficient number of hydrologic training shifts to be made
available for each forecaster to become totally competent in the station hydrology
program.

RECOMMENDATION 3-7: The NWS should reexamine WFO staffing levels

and procedures for developing adequate on-station hydrologic training to avoid
difficulties during critical hydrologic events. This should include an adequate

44


Table D-4. Flint River near Culloden CLUGI, Flood Stage 18 ft

Date

Latest
Report (ft)

Forecast (ft)

Issue Time (EDT)

07/05/94

23.1

Crest near 39 6th

10:35 am.

07/05/94

35.57

Crest near 42 8th

3:30 pm

07/06/94

Crest near 39 today

11:05 am

07/07/94

Crested and falling

12:45 pm

07/08/94

Falling below FS 12th

Crest: 45.73 ft, early am 7/06/94, high water mark
New record level
Previous Flood of Record: 38.4 ft, 3/15/29

D-6

12:15 pm



threatened by the tremendous inflow into the reservoirs behind them. Some small, unregu-
lated earthen dams began to fail, and reports of road and bridge washouts became common.

Within a day after landfall, the forward motion of Alberto slowed. The rains continued, and
some of the larger rivers began to approach flood stage at various locations. Late on July 5,
with the center of Alberto coming to a halt near Atlanta, portions of numerous large rivers
exceeded flood stage; and river flooding became more widespread and significant. By the
morning of July 6, some locations had observed record flooding; and the first crests began to
appear along some of the smaller rivers and at some upstream locations along the larger
rivers. Aiberto’s movement became erratic--the system was now moving westward, looping
back over a portion of its previous track. Additional rainfall caused a progression in
flooding from urban and small stream flooding to river flooding. By July 7, as Alberto’s
center drifted into central Alabama, rainfall finally diminished, both in intensity and in areal
coverage. Tremendous volumes of water were now moving down major river systems in
portions of Georgia, Alabama, and Florida: the Flint, Ocmulgee, Chattahoochee,
Choctawhatchee, and the Apalachicola Rivers. River flooding peaked, both in terms of
coverage and severity, during the period July 6-15; but flooding would continue along
portions of some rivers until close to the end of July.

By far, the worst flooding occurred along Georgia’s Flint and Ocmulgee Rivers and their
tributaries. Some of the hardest hit cities along these rivers include Albany, Macon, and
Montezuma. Across the entire three-state area impacted by the flooding, 17 NWS river
forecast locations set new record flood stages, some breaking the old record by 5-7 feet. In
all, 47 NWS river forecast locations exceeded flood stage. Crests of 5-15 feet above flood
stage were common, while portions of some rivers observed crests that exceeded flood stage
by more than 20 feet. The NWS offices involved in the flood event across the three-state
area issued 657 watches, warnings, and statements related to the event; and the Southeast
River Forecast Center (SERFC) issued 238 NWS internal river forecasts.


APPENDIX A

SUMMARY OF FINDINGS AND RECOMMENDATIONS

CHAPTER 1: BACKGROUND AND OVERVIEW OF THE EVENT

No findings and recommendations in this chapter.

CHAPTER 2: OVERVIEW OF NWS PERFORMANCE

FINDING 2-1: As is generally the case with a synoptic pattern with little or no forcing and
weak steering currents, the National Meteorological Center and National Hurricane Center
models in general did not perform well with regard to the track of the remnants of Tropical
Storm Alberto.

RECOMMENDATION 2-1: The National Weather Service (NWS) should continue to strive
for improvements in tracking tropical systems once they make landfall. It is especially important
that improvements be made in the forecasts at the surface and not just in the mid and upper
levels of the atmosphere. Interactions with the research community within National Oceanic and
Atmospheric Administration (NOAA) (such as the Office of Atmospheric Research) and other
Federal agencies, as well as the academic research community, are especially encouraged.

FINDING 2-2: The quantitative precipitation forecast (QPF) guidance generated by the National
Meteorological Center models was poor (as is common for convective situations during the warm
season) and therefore of limited help to the forecasters. The national QPF guidance frequently
underestimated excessive rainfall amounts and sometimes did not accurately highlight the area
of maximum rainfall.

RECOMMENDATION 2-2: The NWS should continue to strive for improvements in QPFs
for tropical and convective systems.

FINDING 2-3: The Weather Surveillance Radar-1988 Doppler (WSR-88D) Stage I Precipitation
Processing, which runs in the Radar Products Generator, does not currently use rain gage data
to provide potentially better quantitative estimates of the precipitation.

RECOMMENDATION 2-3: Rain gage data must be included in the WSR-88D Stage I

Precipitation Processing as soon as possible, so that the radar-rainfall can be adjusted to avoid
underestimation of rainfall associated with warm tropical events.

A-1


Background and overview information on the hydrologic situation, which appears in
Chapter 1, was contributed by Scott Kroczynski of the Hydrologic Information Center,
Office of Hydrology, Silver Spring, Maryland. Graphics support was provided by
Paul Hrebanach of the Office of Hydrology. Descriptions of the meteorological conditions
and forecasts, which are presented in Chapter 2, were contributed by Bruce Terry of the
Meteorological Operations Division, National Meteorological Center, Camp Springs,
Maryland, and Edward Rappaport of the National Hurricane Center, Coral Gables, Florida.
Debra Anderson, Program Assistant in the Office of Hydrology, edited and formatted this
report into a camera-ready document for publication.

The team was divided into two groups during parts of the survey so that the wide geographic
area of impact could be covered efficiently. One group, composed of Alex, Georgakakos,
and May, traveled through Georgia and the eastern portion of the Florida Panhandle. The
other group, composed of Haffer, Hooke, and Van Demark, concentrated on Alabama and
the western portion of the Florida Panhandle. During the week, the two teams coordinated
their progress by meetings and telephone calls. The survey team conducted its field work on
Monday, July 18, through Friday, July 22. The entire survey team met in Atlanta, Georgia,
on Saturday, July 23.

The consensus of the survey team was that overall NOAA provided good, high-quality
services throughout this event. The report discusses successful features of NOAA’s services
program, as well as recommendations for areas needing improvement.

flddlddl

William H. Hooke
Team Leader

vi


Apalachicola River at Blountstown
July 1994

Chipola River at Marianna
July 1994

0
1°35 7 9 11 13 16 17 19 21 23 25 27 29 31

Time (days) Previous record: 28.6 ft 3/21/29
Peak 127.39 ft 7N084
Floodstage 15 ft
Chipola River at Altha
July 1994
38
30
ro
22
&
B18
40
5

0
123.4 5 6 7 8 9 1014 1213 14 15 16 17 18 19 20

Time (days) prevous record: 388910076
Floodstage : 22ft

C-4

0
123.4 65 6 7 8 9 1011 1213 14 15 16 17 18 19 20

Time (days) Previous recor E27.0 45/75
Peak 7E240 R7AOR4
Flood stage 19 ft
Ocmulgee River at Macon
July 1994
35
30
25
E20
°
8
£15
10
5

0
123.4 5 6 7 8 9 10111213 14 15 16 17 18 19 20

Time (days) Previous record : 29.83 ft 3/19/90
New record
Flood stage



respectively. For the most part, all of the manual 24-hour QPFs were typically not quite heavy
enough and were generally displaced a little too far north and east from the heaviest rain
occurrence. Clearly, the manual 24-hour QPFs issued about 1000 UTC each day did not
completely capture the magnitude of the event. However, quotes from many of the excessive
rainfall discussions and storm summaries that were issued definitely showed that WFB
forecasters were very aware of the dangers of this decaying storm.

2.1.4 DAY-BY-DAY COMPARISON OF NUMERICAL GUIDANCE AND MANUALLY
ISSUED FORECASTS

Between 1200 UTC July 3 and 1200 UTC July 4, as Alberto was making landfall, the heaviest
rains occurred over portions of the western Florida Panhandle and southeastern Alabama, just
to the east of the storm track. The 24-hour manual QPF issued early Monday morning, July 4,
and valid at 1200 UTC Tuesday, July 5, had greater than S-inch rains occurring over
southwestern Georgia and extreme southeastern Alabama. Model QPFs for the same time period
were not nearly as good. The Eta model indicated just over 2 inches of rain for parts of the
Florida Panhandle and southern Alabama and Georgia. The RAFS indicated slightly more than
2-inch rains in central Georgia, and the AVN model forecasted only 0.75 inch of rain for the
Florida Panhandle.

Alberto drifted slowly north-northeastward from near Montgomery, Alabama, on Monday
morning, July 4, to just southwest of Atlanta, Georgia, by Tuesday morning, July 5. Extremely
heavy rains of locally greater than 10 inches occurred near the path of the storm, across parts
of west-central Georgia. QPFs issued by the WFB indicated up to 5 inches of rain over central
Georgia. As was the case the previous day, model QPFs were grossly underforecast compared
to the manual forecasts; and they were generally in the wrong location. The Eta model forecast
a little over 2 inches of rain for southeastern Alabama; the RAFS had 2 inches for southeastern
Georgia; and the AVN forecast had only a paltry 0.9 inch for east-central Alabama. Despite
poor QPFs, the models did a respectable job of forecasting where the storm would be for this
24-hour period, at least as interpreted from their 500-mb prognostication chart (prog). This
added some confidence to the manually prepared QPF issued by the WFB forecaster.

The period between Tuesday, July 5, and Wednesday, July 6, was a great challenge for the
WFB forecasters. The models had been doing a fair job in forecasting the position of the storm
in their 500-mb progs, but they started to diverge on the track of the remnants of Alberto. Only
the Eta model performed well with its 500-mb forecast during this period. It essentially kept
the well-defined, mid-level remains of Alberto nearly stationary in the vicinity of the
Alabama/Georgia border, which turned out to be a very good prediction. The RAFS, on the
other hand, tried to shear the remains out to the northeast into the central and southern
Appalachians, while the AVN model consistently dissipated the system with time. WEB
meteorologists correctly accepted the Eta forecast as early as Monday afternoon. The discussion
issued at 2:30 p.m. EDT noted that "the RAFS forecast seems too quick considering the lack
of upper level winds, and the Eta appears to have the best handle on the situation with a well-
organized vorticity field/upper low meandering ever so slowly northeastward."

19


40

30

Stage (ft)
8

Stage (ft)

0
12345 6 7 8 9 101112131415 1617 18 19 20

% 2.3.45 6 7 8 9 1011 1213 1415 16 17 18 19 20

Flint River at Culloden
July 1994

Stage (ft)

Flint River at Montezuma
duly 1994

Previous record: 38.4 ft 3/5/29
New record: 45.73 ft
Flood stage 18ft

Time (days)

Kinchafoonee River at Preston
July 1994

Time (days) Previous record : 12.16 ft 347/90
Peak 111.62 ft 70694
Flood stage =: 7 ft

123 4 6 6 7 8 9 1011 1213 14 15 16 17 18 19 20

Time (days) Previous record: 27.4 ft 3/17/29
Newrecord : 34.11 ft 7/084
Flood stage: 208

Kinchafoonee River at Dawson
July 1994

20

a

Stage (ft)

40

123.4 5 6 7 8 9 1011121314 15 16 17 18 19 20

Time (days) Previous record: 20.45 ft 3/20/90
New record 26.6 R 70794
Flood stage: 13 ft



FINDING 3-10: Agencies, like FEMA, have made and continue to make great advances in
their abilities to effectively communicate with their users; however, the NWS is not fully
utilizing the recent advances in information technologies.

RECOMMENDATION 3-10: NWS should create national capabilities that parallel the
capabilities of FEMA for special emergency response and disaster relief operations. This should
be coordinated by the regional or national NWS offices, as appropriate for the magnitude of the
event. For example, the NWS should institutionalize the capability to provide support for
satellite feeds coordinated by FEMA which are then made available to other Federal and state
government agencies and locally on cable television.

FINDING 3-11: The limited ability of the NWS to interact with FEMA raised the concern that
the NWS may not be able to synchronize with FEMA and effectively operate an “all hazards"
NWR.

RECOMMENDATION 3-11: The NWS must be careful not to commit to operating an "all-

hazards" NWR without considering issues, such as staffing and length of the NWR program
cycle.

AD


was discontinued west of Gulfport. Alberto continued to strengthen, and the advisory issued at
2100 UTC on July 2 mentioned that, based on the trend at that time, Alberto could be close to
hurricane strength by the time of forecasted landfall. Based on a reconnaissance flight, the
tropical storm warning was upgraded to a hurricane warning at 0000 UTC on July 3, covering
the same portion of the Gulf of Mexico coast (from Gulfport, Mississippi, to Cedar Key,
Florida). In the advisory issued at 0300 UTC on July 3, landfall was estimated to be over
northwest Florida during the morning daylight hours. A tropical storm watch was not issued
for the eventual landfall location of Destin, Florida. However, a tropical storm warning
including Destin was issued with a lead-time of 24 hours; and a hurricane warning was issued
with 15 hours lead-time. Upon landfall (around 1500 UTC on July 3), the hurricane warning
was discontinued. However, a tropical storm warning continued in effect from Cedar Key,
Florida, to Mobile, Alabama. All tropical storm warnings were discontinued at 2100 UTC on
July 3 and, at the same time, Alberto was downgraded to a tropical depression.

NHC issued its last advisory on Alberto at 2100 UTC on July 3. At that time, forecast
responsibility for the remains of Alberto were assumed by the WFB, which issued its first
advisory (storm summary) at 2300 UTC July 3.

2.1.2, EVALUATION OF NMC NUMERICAL GUIDANCE AND STORM TRACK
FORECASTS

The various NMC numeric models are briefly described below:

AVN - Aviation Model, global spectral model that forecasts out to 72 hours
CLIPER- CLimate and PERsistence no-skill model
Eta - Eta Model, Western Hemisphere (northern portion) out to 48 hours with

more resolution in the vertical than the RAFS model
NHC90 - Statistical dynamic model that uses output from the AVN as predictors
RAFS - Regional Analysis and Forecast System, Western Hemisphere (northern
portion) out to 48 hours

Most track model guidance (and the NHC official forecasts based, in part, on that guidance) had
a large left bias prior to about 1200 UTC or 1800 UTC on July 2 (Figure 2-1). The rightward
swing of the official forecast tracks eventually required an eastward shift of the watch/warning
area along the north coast of the Gulf of Mexico.

The performance of the NHC90 model was the best overall (including the depression stage of
the storm), with errors comparable to the long-term average NHC official forecast errors.
Another hurricane model, CLIPER, which has no dynamical input, also forecast the track fairly
well. The Aviation (AVN) model track scheme produced by far the worst storm track forecasts.
The NHC and model guidance intensity forecasts were quite good. Most NHC wind speed
forecasts were no larger than 10 knots for all forecast periods.

12



— = = os
PEE ae 35
. = = oa
ae cmt le MEM |% a
pede Sas zi
Py = wae Re lnm is
- oat KGS rat 7
RWS Sy Of Veer <8s 7

a Eyes Ns TAR gees Wes aa
Y Oiteess
‘BTR; )
way NPA x ie =
om Ke ’ ef =
~— DAB
= MLB
=A),
Fuy tom
aon i

Figure 2-9. Boundaries of county warning areas.

29


FINDING 2-9: The remote job entry (RJE) dial backup did not function because the dedicated
phone line had not been connected to the system. The RJE dial backup had not been tested since
the office moved.

RECOMMENDATION 2-9: RFC staffs must routinely test the RJE dial backup.

FINDING 2-10: The SERFC did not declare a Critical Flood Situation during the Alberto
event, because job processing times were adequate.

RECOMMENDATION 2-10: The declaration of a Critical Flood Situation and use of the crisis
job priority are powerful tools that should be utilized by the RFCs during any critical flood
event.

FINDING 2-11: The Sheriff/Emergency Management Agency (EMA) Director for Sumter
County, Georgia, receives weather watches and warnings from the public broadcast media. The
county does not receive the National Attack Warning System (NAWAS) transmissions and is on
the outside fringe of NOAA Weather Radio (NWR) reception (Americus is 68 miles from the
nearest NWR transmitter). The NWR tone alert does not work reliably in the county because
of this distance.

RECOMMENDATION 2-11: NWS should work with Federal Emergency Management Agency
(FEMA) to ensure that every county emergency management agency/emergency operation center
in Alabama, Florida, and Georgia has a communication link to NAWAS. Additionally, the Gore
Initiative should be implemented as soon as possible to expand the NWR network of transmitters
to reach 95 percent of the population.

FINDING 2-12: The Sheriff of Sumter County, Georgia, as with many other emergency
management officials in the impacted area, expressed a high degree of frustration in making
residents aware of the danger from the floodwaters and of the need to evacuate. Some of the
deaths that occurred were people who had been warned (more than once) to evacuate but failed
to act until it was no longer safe to do so. No flash flood/flood anywhere near the magnitude
of this event had ever occurred in this area; and residents were, for the large part, unable to
realize the dangers they faced until it was too late.

RECOMMENDATION 2-12: More emphasis should be placed on public awareness and
preparedness training for flood and flash flood events. The continued high number of vehicle-
related deaths during floods and flash floods indicates the need to educate the public of the risks
involved with vehicles in flood situations. The "Hidden Danger" video currently being
developed by the NWS should be used to inform the public of the dangers of low-water
crossings.


(a) (b)

(ey (ay

Figure 2-2. QPF graphics for 24 hours ending 1200 UTC July 4, 1994: (a) observed,
(b) manual forecast, (c) ETA forecast, (d) RAFS forecast, and (e) AVN forecast.

15


Table D-14.

Date

Chipola River near Altha, ALTF1, Flood Stage 22 ft

Latest
Report (ft)

Forecast (ft)

Issue Time (EDT)

07/04/94

13.9

Crest near 19 7th

10:10 am

07/05/94

15.4

Crest near 19 7th

10:50 am

07/06/94

17.5

Crest near 20 7th

10:50 am

07/06/94

Crest near 30 9th

5:30 pm

07/07/94

19.1

Crest near 30 9th

12:40 pm

07/08/94

21.2

Crest 26-27 11th

12:45 am

07/09/94

23.13

Crest 26-27 11th

11:55 am

07/10/94

26.2

Crest 29-30 11th (backwater effects)

11:55 am

07/11/94

28.85

Crest 30-31 12th

12:05 pm

07/12/94

29.75

Crest 30-31 tonight

11:45 am

07/13/94

30.2

Crested...began slow fall

Crest: 29.60 ft, pm 7/12/94
Previous Flood of Record: 33.35 ft, 9/20/26

D-16

11:35 am

lt lt a

a ee ee ae


1. The lower portion of the Flint River Basin lies in a large Karst area. Karst areas are
irregular limestone regions with sinkholes and underground caverns and streams. Such areas
can have a significant and complex effect on modeling the hydrology of a basin.

2. The possible hydrologic effects of Big Slough Creek when Flint River stages exceed 32 feet
needs to be investigated. Big Slough Creek joins the Flint River a few miles upstream of
Bainbridge.

3. The stage-discharge relationship for Bainbridge used during this flood event was a graphical
or mathematical extension above 70,000 cfs based on high water marks from the 1925 flood.
The rating that resulted from measurements made during the 1994 flood is significantly different
and has already been implemented in the SERFC forecast model.

FINDING 2-18: The forecast for the Flint River at Bainbridge received
considerable media and public attention when the river crested well below the
forecasted level.

RECOMMENDATION 2-18: The SERFC must investigate the causes for the
Bainbridge forecast error and make the appropriate changes to the hydrologic
forecast model as soon as possible. When the appropriate modifications to the
hydrologic model are completed, NWS personnel (RFC and/or NWSFO) should
make the necessary effort to brief the Bainbridge public officials (and media) on
their findings.

2.4 PREPAREDNESS

The primary mission of the NWS is to save lives and reduce losses to property due to the
weather. Generally stated, this is accomplished by the NWS in two equally important phases.
The first is the generation of hydrometeorological forecasts and warnings; the second is internal
and external preparedness activities.

The offices and individuals contacted by the disaster survey team are contained in Appendix E.
The survey team found that the NWS’s internal state of preparedness prior to and during the
event was, for the most part, adequate. However, the survey team found external awareness of
the NWS’s hydrologic services to range from a high level to a relatively low level. For
example, awareness ranged from knowing the NWS contact by name to confusion over who
provides river forecasts and warnings. The variance seemed to be directly related to frequency
of personal contact by NWS personnel with all levels of the emergency management community.

Overall, the survey team judged NWS preparedness activities to be acceptable. The fact that
33 people lost their lives caused much concern. The survey team felt that this high figure could
perhaps have been lower had NWS preparedness activities been more frequent and
comprehensive in two broad areas: (1) the number of personal visits to the user community by
the Warning Coordination Meteorologists (WCM) and Service Hydrologists (SH); and,

36



Table D-9. Flint River at Newton NEWGI, Flood Stage 24 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/05/94 8.88 | Crest 31-32 13th 10:35 am
07/05/94 Crest near 38 12th 3:30 pm
07/06/94 14.7 | Crest near 41 12th 11:05 am
07/07/94 18.41 | Crest near 45 11th 12:45 pm
07/08/94 24.48 | Crest near 45 11th 12:15 pm
07/09/94 35.23 | Crest near 45 11th 12:25 pm
07/10/94 40.20 | Crest near 46 12th 11:25 am
07/11/94 42.69 | Crest 45-46 12th 11:55 am
07/12/94 44.44 | Crest 45-46 tonight 11:15 am
| 07/13/94 45.24 | Near crest...fall below FS 18th 11:45 am
07/14/94 44.82 | Crested...fall below FS 18th 11:50 am

Crest: 45.25 ft, 6:00 am 07/13/94

New record level

Previous Flood of Record: 41.3 ft, 1/21/25

USGS Measurements: 41.24 ft = 86,000 cfs 7/12/94;
43.5 ft = 94,400 cfs 7/12/94



RECOMMENDATION 3-6: The NWS should reassess its staffing philosophy for field offices;
each WFO should have a resident SH.

FINDING 3-7: Staffing levels at the NWSFOs surveyed by the team, coupled with operational
workloads and off-station training requirements, made it virtually impossible for a sufficient
number of hydrologic training shifts to be made available for each forecaster to become totally
competent in the station hydrology program.

RECOMMENDATION 3-7: The NWS should reexamine WFO staffing levels and procedures
for developing adequate on-station hydrologic training to avoid difficulties during critical
hydrologic events. This should include an adequate number of nonoperational shifts for each
meteorologist to be trained to handle hydrologic crises at all times. In addition, Meteorologists
in Charge should adhere to the guidance that SHs work no more than 20 percent of their time
on forecast shifts.

FINDING 3-8: The personal contacts between the local EMA officials and WSO staffs
contributed to their satisfaction with the NWS services. When these offices spin down, the
responsibility switches to a single WCM.

RECOMMENDATION 3-8: A WCM team approach should be considered with other WFO
staff members (e.g., the SH) interacting with the customers.

FINDING 3-9: One-on-one phone contacts between the NWS and all types of users are
frequently associated with the user’s satisfaction with the service provided by the NWS.
However, the number of individual phone calls which can and should be made is limited. An
additional drawback for the users who rely on phone contacts is that they have to verbally
repeat, dictate, or retype (or some combination) the information in order for it to be shared.

RECOMMENDATION 3-9: The NWS must be more sophisticated in its use of communication
and dissemination technologies. For example, the NWS should take advantage of aspects of the
Information Superhighway (e.g., Internet) to coordinate with the public and other Federal, state,
and local agencies as much as possible. Through increased electronic dissemination of NWS
products, the NWS staff’s time is more effectively used by allowing direct communication with
many more users/agencies. Additionally, users/agencies getting information directly from the
NWS can then further distribute it automatically without having to repeat, dictate, or retype the
information.

Another approach is to integrate into routine NWS field operations a range of communications

tools (e.g., satellite broadcast, packet radio, teleconferencing) in order to match the ever-
increasing technical capabilities of the NWS’ many customers.

A-8


Table D-10. Flint River at Bainbridge BGEGI, Flood Stage 25 ft

Latest Forecast (ft) Issue Time (EDT)
Report (ft)

07/05/94 19.77 | Crest 28-29 14th 10:35 am
07/05/94 Crest near 34 14th 3:30 pm

07/06/94 20.55 | Crest near 40 13th 11:05 am
07/07/94 22.65 | Crest near 45 13th 12:45 pm
07/08/94 25.3 | Crest near 45 13th 12:15 pm
07/09/94 30.05 | Crest near 45 13th 12:25 pm
07/10/94 33.4 | Crest near 45 13th 11:25 am
07/11/94 35.25 | Crest 44-45 14th 11:55 am
07/12/94 36.00 | Crest 43-44 14th 11:15 am
07/13/94 36.65 | Crest 37-38 14th 11:45 am
07/14/94 37.10 | Crest 37-38 this evening 11:50 am T
07/14/94 37.15 | Near crest 12:40 pm
07/15/94 37.10 | Crested yesterday...near 37 today...fall | 11:40 am

below FS 22nd
07/16/94 36.44 | Fall below FS 22nd 10:50 am

Crest: 37.3 ft 11:00 am 07/14/94, High Water Mark

New record level

Previous Flood of Record: 40.9 ft, 1/24/25

USGS Measurements: 36.23 ft = 101,000 cfs, 4:00 pm 7/12/94
37.18 ft = 108,000 cfs, 12:05 pm 7/14/94

D-12


&

Figure 2-7. Rain gage locations under various WSR-88D umbrellas.



AFB
AFOS
AVN
AWIPS
CAC
cfs
CLIPER
COE
CWA
DNR
EDT

EOC
Eta
FEMA
FFA
FFW
FLS
FLW
FS
GOES
HAS
HDRAIN

HSA

LARC
mb

MIC
mph
NAWAS
NCCF
NCDC
NEXRAD
NHC
NHC90
NMC
NOAA
NWR

ACRONYMS AND ABBREVIATIONS

Air Force Base

Automation of Field Operations and Services

AViatioN (model), global spectral model that forecasts out to 72 hours
Advanced Weather Interactive Processing System

Climate Analysis Center

cubic feet per second

CLImate and PERsistence hurricane tracking model

U.S. Army Corps of Engineers

County Warning Area

Department of Natural Resources

eastern daylight time

Emergency Management Agency

Emergency Operations Center

Eta model, Western Hemisphere (northern portion) out to 48 hours
Federal Emergency Management Agency

Flash Flood Watch

Flash Flood Warning

Flood Statement

Flood Warning

Flood Stage

Geostationary Operational Environmental Satellite
Hydrometeorological Analysis and Support

hourly digital rainfall product (WSR-88D Stage I Precipitation
Processing)

Hydrologic Service Area

Interactive Forecast Program

Limited Automatic Remote Collector

millibar

Meteorologist in Charge

miles per hour

National Attack Warning System

NOAA Central Computer Facility

National Climatic Data Center

Next Generation Weather Radar

National Hurricane Center

statistical dynamic model that uses output from the AVN as predictors
National Meteorological Center

National Oceanic and Atmospheric Administration

NOAA Weather Radio

National Weather Service

xiii


The survey team felt expectation levels of the NWS by the public and emergency management
community were based on its past capabilities. Hence, relative to the NWS’s capabilities during
its transition and modernized phases, the level of expectations by the users was perhaps low.
This poses a significant challenge to the NWS: Improving the public’s awareness level of the
impacts of both short-term and longer-term hydrometeorological events must be put on at least
the same level as improvement of the NWS’s scientific capabilities in the generation of forecasts
and warnings.

FINDING 2-19: Some communities, and perhaps emergency managers, were not
as prepared for the disastrous floods as they could have been if there were greater
personal contact and education on floods by NWS WCMs and SHs.

RECOMMENDATION 2-19: NWS policy should require periodic (annual if
possible) personal visits by the WCMs and/or SHs to emergency management and
other action agencies from the state to the local level. These contacts should
include a review of the flood threat to the local community (emphasizing the
threat to vehicular passengers) and a review of the hydrologic services that the
NWS provides. This educational process should specify what products are
available, how they can be used, and where they can most efficiently be obtained.

Several individuals interviewed by the survey team remarked that there may have been an
overemphasis on the landfall of Tropical Storm Alberto and not enough attention focused on the
potential for heavy rain and flooding associated with the storm. This is probably more of a
media and public perception problem than a forecast problem. For example, the Meteorological
Operations Division of NMC highlighted a "very dangerous flash flood and flood situation for
much of Georgia today [July 4] into tonight as the remnants of Alberto drift slowly north."

FINDING 2-20: The public’s perceived threat from Alberto appeared to lessen
once it made landfall.

RECOMMENDATION 2-20: The NWS and NOAA should take maximum
advantage of the recommendations from the 1995 Interdepartmental Hurricane and
the NOAA Hurricane Conferences, which focused on the inland effects of tropical
cyclones, in order to enhance the public’s perception of the dangers associated
with landfalling tropical cyclones. In addition, the WCMs in all areas which
might be affected by the aftermath of decaying tropical cyclones should reenforce
the potential for severe flooding from such storms with the user community.

There is room for improvement in better identification of flood-prone areas. Traditionally
non-NOAA agencies identified flood-prone areas, most often as part of a flood insurance study.
If potential flood inundation maps were widely available and used, the NWS and emergency
management personnel could coordinate more easily with local communities to communicate the
potential impact a disastrous flood could have on their community.

38


Transition to the modernized NWS and its associated staffing
configurations pose special challenges. Throughout the affected region,
offices had to deal with added stress in their handling of the event by
conflicts between scheduled training and urgent operations, by recent
introduction of the new technologies (particularly the WSR-88D), and
by vacancies. The NWS should reexamine its approach to staffing and
training during the transition with an eye to the special vulnerabilities
represented by extreme events and make necessary adjustments. In
addition, the NWS should continue working with management at the
Department of Commerce, the National Oceanic and Atmospheric
Administration (NOAA), and the Office of Management and Budget, and
with the Congress, to ensure that this is the last such wrenching
modernization the NWS undertakes. In the future, modernization must
be a continuing process, not a disruptive event.

Preparedness is a special issue. As warnings and forecasts of particular
events improve, opportunities for saving lives and property will depend
increasingly on preparedness. In the modernized NWS, it will be
challenging for a smaller number of offices to work with communities
and other affected parties spread over large geographical areas to build
the needed relationships and coordination on an ongoing basis. The
NWS should identify resources for improving the capabilities of Weather
Service Forecast Offices and future Weather Forecast Offices to build
community preparedness with special focus on taking advantage of the
"information highway."

New demands on NOAA for information are created by increasing and
changing societal vulnerability to weather, growing awareness of this
vulnerability, and technological advances, especially in computing and
communications. _ NOAA should continue to shift emphasis from
particular events to ongoing processes of preparedness. It should
create national capabilities that parallel the Federal Emergency
Management Agency’s capabilities for special emergency response and
disaster relief operations. NOAA should also give more emphasis to the
development of all-hazard telecommunications capability for NOAA
Weather Radio.

xi


indicates the need to educate the public of the risks involved with vehicles in
flood situations. The "Hidden Danger" video currently being developed by the
NWS should be used to inform the public of the dangers of low-water crossings.

FINDING 2-13: The Sheriff of Sumter County, Georgia, had high praise for
NWS products and service during this event and did not think there was anything
the NWS could have done to reduce the loss of life during this event. He did
think it is a mistake for the NWS and the media to emphasize tropical storms only
up until landfall; and then, in some cases, the public perceives that there is no
danger because of a relatively weak wind-producing storm.

RECOMMENDATION 2-13: The NWS should work with the media to educate
the public on the fact that heavy rains and widespread flooding from tropical
storms and hurricanes may have as much, and in some cases even more,
detrimental impact as winds at landfall.

FINDING 2-14: The disaster survey team found that the Flash Flood Warnings
issued in this event were generally accurate and timely. However, many lacked
a strong enough indication of the life-threatening nature of the flash flooding.

RECOMMENDATION 2-14: NWS offices should strive to better recognize
truly extreme rainfall events and, in those events, use the strongest possible
wording in the warnings and statements issued to make the public more cognizant
of the life-threatening nature of the event.

2.3.2. RIVER FLOODING

The area affected by flooding from the rains of Alberto stretched from central Georgia southwest
into southeastern Alabama and southward into the Florida Panhandle. The river basins with the
most severe flooding included the Ocmulgee and Flint Basins in Georgia, the Chattahoochee
Basin along the Georgia-Alabama border, the Choctawhatchee Basin in Alabama, and the
Apalachicola Basin in Florida.

Appendix B includes the USGS listing of the crest values, previous record crests, and return
interval of the crests for this event. Appendix C also includes selected hydrographs. Table 2-2
summarizes the number of locations by basin that equaled or exceeded the 100-year recurrence
interval and the number of locations that exceeded the previous record crest.

The SERFC issued 238 river forecasts for locations in the impacted area during this event. On
July 3, 24-hour operations began and continued through July 9 at 9 p.m. with the brief exception
from midnight July 4 to 6 a.m. on July 5. The SERFC Hydrometeorological Analysis and
Support (HAS) unit had not yet become operational and contained only one of the three
positions. As was Southern Region policy at the time, the SERFC did not use QPF in the
preparation of river forecasts since the majority of the WSFOs in their forecast area did not

32



CHAPTER 2

OVERVIEW OF NWS PERFORMANCE

2.1 STORM PREDICTION

The National Meteorological Center (NMC) provides weather analyses and forecast guidance for
use by field offices. Two divisions within NMC, the National Hurricane Center (NHC) and the
Weather Forecast Branch (WFB) of the Meteorological Operations Division, share responsibility
for tracking and forecasting tropical systems. The NHC has primary responsibility for forecasts
until, in coordination with the WFB, it is decided that the WFB assumes the responsibility.
WEB is also responsible for issuing the Quantitative Precipitation Forecast (QPF) guidance for
the contiguous United States.

2.1.1 SUMMARY OF STORM TRACK AND FORECASTS

Alberto began as a tropical depression just west of Cuba at approximately 0600 UTC on
Thursday, June 30, and was upgraded to a tropical storm at 0000 UTC on July 2. At that time,
steering winds throughout the atmosphere indicated Alberto would track towards the Gulf Coast
of the United States, but exactly where it would make landfall was uncertain. Forecasts issued
from the NHC at this time took Alberto into Louisiana very early Monday, July 4, while
forecasts from the WFB took Alberto very near Mobile Bay, Alabama, on Sunday afternoon,
July 3. As synoptic forcing became clearer, the forecasts from the NHC and WFB converged.
By the morning of July 2, landfall was predicted by the NHC and the WFB to be in southern
Alabama and the western Florida Panhandle, respectively, around midday Sunday, July 3.
Forecasts issued later in the afternoon of July 2 were almost identical, with Alberto forecast to
make landfall in the western Florida Panhandle around noon on Sunday, July 3. Subsequent
forecasts remained extremely similar and, as it turns out, quite accurate, since Alberto did come
ashore in the western Florida Panhandle at 1500 UTC July 3 as a very strong tropical storm.

The storm, which produced near-hurricane-force winds as it moved inland, began to quickly
weaken later on Sunday. The emphasis at this point shifted to the potential for very heavy rains,
since Alberto had plenty of tropical moisture associated with it and would likely be a slow-
moving storm after landfall.

The NHC issued its first advisory on the tropical depression at 2100 UTC on June 30. Near
0000 UTC on July 2, based on reconnaissance data, the depression was upgraded to Tropical
Storm Alberto. A tropical storm watch was issued at 0900 UTC on July 2 for the northern Gulf
of Mexico coastal areas from Sabine Pass, Texas, to Pensacola, Florida. Later that morning
(1500 UTC), a tropical storm warning was issued for the north Gulf of Mexico coastal areas
from Gulfport, Mississippi, to Cedar Key, Florida. At that same time, the tropical storm watch

11


Alabama

Florida

Figure 1-1. Major river basins impacted by flooding in July 1994 as a result of Alberto:

Flint, Ocmulgee, Chattahoochee, Choctawhatchee, and Apalachicola River Basins.


FOREWORD

The National Weather Service (NWS), one of the line offices of the Department of
Commerce’s National Oceanic and Atmospheric Administration (NOAA), has broad Federal
responsibility to provide public forecasts and warnings of weather and river conditions for
the protection of life and property and in support of the Nation’s commerce. NOAA
conducts a survey of major natural disasters to thoroughly assess the performance of its
warning system in all aspects, from data collection and assimilation through creation and
dissemination of products and, ultimately, effective user response. This report of the disaster
survey team’s findings regarding the disastrous floods of the southeastern United States in
1994 identifies opportunities to improve the NWS’s weather and flood warning system, not
only in the affected region but throughout the Nation.

The survey team was sent to the region affected by major flooding in July 1994. The team
visited NWS offices that provide flood warning service to the affected region. They
interviewed numerous officials and representatives of the print and broadcast media.

I would like to express the special gratitude of the NWS to the numerous Federal, state, and
local officials and media representatives in Alabama, Georgia, and Florida who helped the
survey team. Having provided admirable service to the public through this disastrous flood
event, you also aided the survey team in evaluating the NWS’s warning services.

Elbert W. Friday, Jr.
Assistant Administrator
for Weather Services

vii


APPENDIX C

HYDROGRAPHS OF OBSERVED RIVER STAGE
. FOR SELECT FORECAST POINTS

This appendix contains hydrographs (plot of river stage versus time) for selected
forecast points affected by Tropical Storm Alberto. The hydrographs include only the stages
reported at 7 a.m.; consequently, they may not include the peak if it occurred outside the
7a.m. window. In addition to the observed river stages, the figures that follow contain
(1) the name of the forecast point, (2) a horizontal line at the flood stage level and text
stating the flood stage, (3) the date and river stage of the previous record, and (4) the date
and river stage of the peak during the Alberto event.

I
:

C1


(a) (b)

(ey (ay

Figure 2-3. QPF graphics for 24 hours ending 1200 UTC July 5, 1994: (a) observed,
(b) manual forecast, (c) ETA forecast, (d) RAFS forecast, and (e) AVN forecast.

16


The flooding took a significant toll on human life, as a total of 33 persons perished’. Of
that total, 31 deaths occurred in Georgia, while the other 2 occurred in Alabama. Many of
the fatalities, as is typical with flood events, occurred as a result of flash flooding’; and most
occurred in vehicles. In addition, approximately 50,000 people were forced from their
homes due to the flooding. More than 18,000 dwellings were damaged or destroyed by the
floods, and nearly 12,000 people applied for emergency housing. In Macon, -Georgia, the
fresh water supply to nearly 160,000 people was disrupted when the water treatment plant,
located along the banks of the Ocmulgee River, was flooded. Some residences were without
fresh water for as long as 19 days. In addition, thousands of people and pieces of equipment
were engaged in various flood-fighting efforts throughout the three-state area impacted by the
flooding. Dozens of Federal, state, and local government agencies, private organizations, as
well as various volunteer groups, were heavily involved in the massive mobilization of
resources. Federal agency participation included, but was not limited to, the Federal
Emergency Management Agency (FEMA), U.S. Army, U.S. Army Corps of Engineers,
U.S. Department of Transportation, U.S. Department of Housing and Urban Development,
and Small Business Administration.

With respect to property damages, the estimates are nearly $750 million‘ across the States of
Georgia, Alabama, and Florida as a result of this flood event. In addition to the more than
18,000 dwellings damaged or destroyed, hundreds of bridges and well over 1,000 roads
sustained damages. Also, 218 dams (most of them small dams located in Georgia) were
damaged by the flooding, many of which failed altogether. Agricultural losses accounted for
approximately $100 million. In the States of Georgia, Alabama, and Florida combined,
more than 900,000 acres of crops were affected by the flooding. Georgia and Alabama
suffered the greatest crop losses with more than 400,000 acres in each state impacted. In all
three states, peanuts and cotton were the commodities most severely affected. Livestock
losses were also significant, especially to poultry, with as many as 250,000 chickens
reportedly lost to the flooding.

1.3. HYDROMETEOROLOGICAL ANALYSIS
While Tropical Storm Alberto will not likely be remembered for its wind nor its storm surge,

it most certainly will be remembered, especially amongst Georgians, for its rainfall and
flooding. The following sections describe, in some detail, the tropical weather system that

2This total includes 26 fatalities directly related to the flooding and 7 fatalities indirectly related. Fatalities directly related to flooding
would include individuals who perished when their vehicles were swept away by floodwaters. Indirect fatalities might include individuals
who perished when their vehicles became involved in accidents attributed to rain-slickened roadways.

2Flash flooding is characterized by rapid development as a result of intense precipitation. Flash floods are generally of short duration,
usually on the order of several hours. Typically, small streams and urban areas are affected by flash flooding. Flash floods are often
violent and very forceful and are one of the leading causes of weather-related fatalities. When flash flooding persists over prolonged periods
of time due to continued rainfall, the cumulative effect can lead to significant flooding of larger river systems, as occurred in Georgia in
July 1994, In this sense, widespread flash flooding can be thought of as the preliminary phase to major river flooding.

“Some independent damage estimates range as high as $1 billion.

2


Model QPF guidance showed essentially the same trends as previous days, although the AVN
got closer for the 24-hour period ending on July 7. The Eta again gave the best QPF guidance
with a forecast of greater than 3-inch rains for east-central Alabama. The RAFS was much too
far north and east with its maximum rain, having forecast a 2.5-inch maximum near the
Georgia/South Carolina border. Somehow, even though the AVN continually tried to dissipate
the feature, it still forecast a 3-inch rainfall maximum over central Alabama. This in itself is
significant, though, since AVN rarely forecasts rains in excess of 2-3 inches in a 24-hour period.

By late Thursday, July 7, any circulation associated with Alberto was becoming increasingly
hard to find and, by very early Friday, July 8, the system had dissipated completely. Between
1200 UTC Thursday, July 7, and 1200 UTC Friday, July 8, only isolated greater than 3-inch
rains occurred, mostly in central and southwest Alabama.

FINDING 2-2: The QPF guidance generated by the NMC models was poor (as
is common for convective situations during the warm season) and therefore of
limited help to the forecasters. The national QPF guidance frequently
underestimated excessive rainfall amounts and sometimes did not accurately
highlight the area of maximum rainfall.

RECOMMENDATION 2-2: The NWS should continue to strive for
improvements in QPFs for tropical and convective systems.

2.2 PRECIPITATION

This section focuses on the acquisition and use of precipitation data. A description of the heavy
precipitation that accompanied Alberto and the storm total isohyetal analysis (Figure 1-4) is
contained in section 1.3.2. Section 2.1.3 discusses the NMC-issued QPF (NWS field offices did
not issue QPFs).

2.2.1 NEXRAD WSR-88D

Figure 2-6 shows that Weather Surveillance Radar-1988 Doppler (WSR-88D) umbrellas provide
almost complete coverage of the SERFC area of responsibility, which includes all the areas
affected by Alberto. Some of the WSR-88Ds in the SERFC area were recent acquisitions, with
acceptance of the radars at NEXRAD Weather Service Forecast Office (NWSFO) Atlanta just
days before Alberto and at Warner Robbins Air Force Base (AFB) in January 1994. The NWS
staff at NWSFO Atlanta and NWSFO Birmingham and at SERFC were adequately trained in the
use of the WSR-88D prior to installation of the equipment.

The three stages of NEXRAD precipitation processing are described below to provide some
background information. Stage I Precipitation Processing is performed within the WSR-88D
itself and is designed to incorporate up to 50 ground-based precipitation gages to adjust the
WSR-88D precipitation estimates (see Figure 2-7 for rain gage locations under the various
WSR-88D umbrellas). Subsequent steps in WSR-88D precipitation processing require interactive

21


Table D-22. Oconee River near Penfield PNFGI, Flood Stage 11 ft ’

Date Latest Forecast (ft) Issue Time (EDT)

Report (ft)

07/06/94 11.5 | Crest near 13 7th 11:05 am f

07/07/94 11.65 | Falling below FS today 12:45 pm !
07/08/94 8.45 | Below FS and falling 12:15 pm

Crest: 12.10, 8:45 pm 07/06/94
Previous Flood of Record: 23.23, 3/17/90

D-24 os


0S eee

Table D-15. Ocmulgee River at Macon MACGI, Flood Stage 18 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/05/94 11.5 | Crest near 19 8th 10:35 am
07/05/94 13.3 | Crest near 22.5 8th 11:00 am
07/05/94. 21.0 | Crest near 25 8th 3:30 pm
07/06/94 26.7 | Crest near 29 8th 2:00 am
07/06/94 29.68 | Crest near 31 6th pm 6:53 am
07/06/94 31.1 | Crest near 32.5 7th 11:05 am
07/06/94 33.8 | Crest near 35 7th 5:00 pm
07/07/94 Crest near 35 today 14:45 pm
| 07/08/94 Crested... falling 12:15 pm

Crest: 35.4 ft, early 07/07/94
New record level
Previous Flood of Record: 29.90 ft, 3/19/90

D-17



was Alberto, from its origin as a tropical wave over western Africa to its dissipation as a
tropical depression over central Alabama.

1.3.1 STORM GENESIS AND LANDFALL

The tropical -weather system which would eventually become Alberto was first detected as a
tropical wave over western Africa on Saturday, June 18. Moving on a westerly course, the
wave traversed the tropical Atlantic Ocean uneventfully until it neared the Virgin Islands
when some increase in thunderstorm activity occurred. However, thunderstorm activity
diminished 2 days later when the wave neared the Bahamas.

The wave continued moving westward and, on June 29, moved across Cuba where thunder-
storm activity rapidly increased; and a very weak circulation became evident. With the
system located in the vicinity of the western tip of Cuba, a National Oceanic and
Atmospheric Administration (NOAA) reconnaissance aircraft was sent to investigate the
disturbed weather area. Based on the information obtained from that flight, NOAA’s
National Hurricane Center proclaimed the system the 1994 Atlantic Hurricane Season’s first
tropical depression on June 30 (see Figure 1-3 for Alberto’s track). Still moving westward,
the poorly organized depression cleared Cuba then took a turn to the northwest into the Gulf
of Mexico where it became better organized. Reconnaissance aircraft data indicated that the
depression then strengthened to a tropical storm® at approximately 0000 UTC, July 2, at
which time the system was named Tropical Storm Alberto.

Alberto then began to track northward towards the Florida Panhandle as it continued to
gradually intensify. Peak intensity was reached just prior to landfall when Alberto’s
sustained winds were 60-65 mph (55 knots), and the central pressure of the storm was near
993 millibars (mb). Alberto’s center made landfall near the town of Destin, Florida, at
1500 UTC on Sunday, July 3, approximately 39 hours after becoming a tropical storm. On
Sunday evening (0000 UTC July 4), just a few hours after landfall, the storm was down-
graded to a tropical depression. For the next 2 days after landfall, the remnants of Alberto
moved north-northeastward at a progressively slower forward speed, eventually coming to a
halt near Atlanta, Georgia, on July 5. The remnants of Alberto then began to backtrack,
moving westward into east-central and then central Alabama. The system dissipated during
the evening hours of Thursday, July 7, over central Alabama.

1.3.2, DESCRIPTION OF THE ANTECEDENT CONDITIONS AND HEAVY
PRECIPITATION

With respect to the antecedent conditions prior to Alberto’s arrival, much of the spring of
1994 was quite dry throughout the Southeast. In fact, many southeastern residents were

5A tropical storm is defined as a tropical low pressure system which has sustained wind speeds of 39 mph (34 knots) or greater. When
a tropical low-pressure system achieves tropical storm strength, it is given a name, such as "Alberto." A tropical storm is stronger than a
tropical depression but weaker than a hurricane, which has sustained wind speeds of at least 74 mph (65 knots).

3


Table D-21. Altamaha River at Doctortown DCTGI, Flood Stage 14 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/08/94 8.89 | Crest near 14 18th 12:15 pm
07/09/94 9.05 | Crest near 14 18th 12:25 pm
07/10/94 9.15 | Crest near 14 18th 11:25 am
07/11/94 9.3 | Crest near 14 18th 11:55 am
07/12/94 9.4 | Crest near 14 18th 11:15 am
07/13/94 9.65 | Crest 14-15 18th 11:45 am
07/14/94 9.78 | Crest 14-15 18th 11:50 am
07/15/94 10.06 | Crest 14-15 18th 11:40 am
07/16/94 11.91 } Crest 14-15 18th 10:50 am
| 07/17/94 13.84 | Crest 14-15 18th 11:10 am
| 07/18/94 14.44 | Crest 14.5-15 this evening 11:05 am
07/19/94 14.56 | Crested early this morning...now 11:10 am

falling

Crest: 14.57 ft, 2:30 am 7/19/94
Previous Flood of Record: 18.6 ft, 1/23/25

D-23



[mi2, square miles;

ft, feet above an arbitrary datum; ft/s, cubic feet per second; *, new peak of record; a, approximately; d, discharge may have been affected by dam break; --, not
determined or not applicable; <, less than; >, greater than; number in () is the ratio of the peak discharge to the 100-year flood discharge. Source:
from U.S. Geological Survey data through 1990 water year. Other data from U.S. Geological Survey reports or data bases]

Recurrence intervals calculated

‘Maximum prior to July 1994 Maximum in July 1994
Discharge
Drain- recurrence
USGS station agearea _, Period of Discharge Stage Discharge interval
number _ Stream and place of determination (mi?) record Year Stage (ft) (ft/s) Day (ft) (fC ys) (years)
OCMULGEE RIVER BASIN
02204500 South River near McDonough, Ga 456 1940-82, 94 1946 24.70 34,500 6 28.70 *41,000 >100 (1.1)
02207500 Yellow River near Covington, Ga 378 1936, 45-65,
76-94. 1936 29.90 30,000 6 13.46 4530 <2
02210500 — Ocmulgee River near Jackson, Ga 1,420 1912, 20, 40-
w 65, 76-82,
ne 88-94. 1919 26.80 69,000 6 26.87 69,000 Regulated
02212500  Ocmulgee River at Juliette, Ga 1,960 1886, 1916-21,
49, 75-88,
90, 94 1948 33.10 78,000 6 41.45 *100,000 >100 (1.2)
02213000  Ocmulgee River at Macon, Ga 2,240 1887, 1893- 29.90
1994 1948 (1990) 83,500 6 354 *107,000 >100 (1.2)
02213500 Tobesofkee Creek near Macon, Ga 182 1929, 38-94 1929 25.40 12,700 6 39.52 ¥54,200 >100 (3.5)
02213700  Ocmulgee River near Warner Robbins, Ga 2,690 1973-94 1990 15.85 81000 7 21.75 *105,000 >100 (1.2)
02214820 — Mossy Creek near Perry, Ga 92.9 1979-94 1981 8.27 788 6 = 19.86 *24,000 >100 (4.7)
02215000  Ocmulgee River at Hawkinsville, Ga 3,800 1877, 1909-80,
83-94 1925 36.50 79000 9 40.91 *100,000 >100 (1.2)
02215100  Tucsawhatchee Creek near Hawkinsville, Ga 163 1984-94 1991 14.13 4740 7 1537 *5,960 25
02215260  Ocmulgee River at Abbeville, Ga 4,460 1902-65, 88-94 1925 19.40 88,000 11 23.10 *100,000 >100 (1.2)
02215320  Ocmulgee River near Jacksonville, Ga 4,890 1948, 69-72,
75-71, 94 1948 17.29 70000 13 19.79 *96,000 100
02215500  Ocmulgee River at Lumber City, Ga 5,180 1909-94 1925 26.30 98400 15 24.59 92,900 85



50

Flint River at Albany
July 1994

Stage (ft)

0
12345678

9 10 11 12 13 14 15 16 17 18 19 20

Time (days) Previous record :37.84 ft 1/21/25
New record 243.03 ft 71194
Flood stage 120 ft
Flint River at Bainbridge
July 1994
40

8

sage

ee

Stage (ft)
8

Ss

Flint River at Newton
July 1994

Stage (ft)

0
123.45 6 7 8 9 1014 1213 14 15 16 17 18 19 20

Previous record: 41.3 ft 1/21/25
Newrecord — : 45.24 ft 713/94
Flood stage: 24 ft

Time (days)

Apalachicola River at Woodruff TW
July 1994

t) 0

12345 6 7 8 9 1011 12131415 16 17 18 19 20 13 5 7 9 1113 15 17 19 21 23 25 27 29 31

Time (days) 40. 4125 Time (days) Previous record: 74.2 ft 3/2180
(days) Previous record:40.8 ft 12 (days) Newrecord. 7629 87/1084

7.2 ft 7H 4194
Flood stage ft

C-3

Flood stage 66 ft


7/72 UTC
7/7/00 UTC

Alabama

G7ane UTC

iY
7/5/12 UTC
7/5/00 UTC

7/6/00 UTC
7/6/12 UTC

7/4/12 UTC
Georgia

7/4/00 UTC

GQ 73h2 UTC
Mey"

8 7/3/00 UTC

lo) 7/2100 UTC

TAN2 UTC

@ Tropical Depression

6 Tropical Storm

L

) Matae

7/1/00 UTC

mak

Figure 1-3. Alberto’s track, July 1994.



Setaatinamainamd

APPENDIX E

DISASTER SURVEY TEAM CONTACTS

CONTACTS BY BOTH TEAM 1 AND TEAM 2:

U.S. Army Corps of Engineers: Bob Watson, Chief, Water Management,
South Atlantic Division

Randy Miller, Chief, Hydraulics and
Hydrology, Savannah District

Ed Burkett, Chief, Water Management,
Mobile District

Federal Emergency Management
ency: Phil Cogan, Disaster Field Office

Georgia Emergency Management
Agency: Ken Davis

National Weather Service Offices:

Southeast River Forecast Center: David Helms, Hydrologist in Charge

WSFO Atlanta (GA): Carlos Garza, Meteorologist in Charge;
Barry Gooden, Warning Coordination
Meteorologist

WSFO Melbourne (FL)(via phone): Bart Hagemeyer, Meteorologist in Charge

Len Mazarowski, Service Hydrologist


AYNI
“4

va

Figure 2-1. NHC track guidance showing projected storm track with model names indicated at
the end of the trajectory and actual storm track depicted by the line with open circles.

13


number of products issued over NWWS by the NWS offices outside of their home states, they
generally chose to receive only those products issued by NWS offices in their own states. For
example, even though products were issued, the survey team found that the Houston County,
Alabama, emergency managers lacked river forecast and warning information because they chose
not to receive flood products issued by WSO Columbus (Georgia) and NWSFO Atlanta
(Georgia) even though the products covered Houston County. Universal Generic Codes (UGC)
enable users to be more selective in the products they receive. Flash Flood Warnings currently
use the UGC codes, but River Statements (RVS), Flood Statements (FLS), and Flood Warnings
(FLW) do not. UGC will be included in RVS, FLS, and FLW once they are produced by the
AWIPS River Product Formatter.

FINDING 3-4: At least one member of the emergency management community
chose not to be burdened with the numerous products sent via NWWS for a
neighboring state. As a result, critical forecasts and warnings for that county
were not received. NWWS users want to efficiently receive weather information
that pertains only to their jurisdictions.

RECOMMENDATION 3-4: Users need the ability on NWWS to parse only
those hydrologic products that apply to their areas of responsibility, e.g., a given
county. The NWS should require the use of generic codes on all NWS public
hydrologic products until AWIPS is implemented, and the WCMs should work
with the users to insure that all necessary products are being received.

3.1.2 STAFFING

Attempts were made to supplement field office staffs during the disaster with personnel from
other field offices. At the SERFC, an additional hydrologist was brought in from the West Gulf
RFC. At WSO Pensacola (Florida), the previous MIC, who had transferred to WSO Mobile
(Alabama), was called back to help out. While this approach may seem laudable, its practicality
as a mainstay of staffing plans is questionable. To provide an effective supplement, personnel
sent to offices during an emergency must be capable of providing specific hydrometeorological
expertise for the geographic area of concern. The nature of the science of hydrology and, to
a limited extent, the science of meteorology requires knowledge of the area. Without such
knowledge, personnel sent during emergencies often are little help to the receiving office. In
fact, time spent getting these individuals to a point where they can contribute to ongoing
operations reduces the time available to the on-site staff to perform their jobs. As a result of
this dilemma, field offices are often reluctant to accept off-site assistance. In addition, there
seems to be an unspoken philosophy that accepting such assistance is a reflection on the
competence of the office in question. The net result is that field offices tend to "make do" with
the staff available during disasters. This often leads to field office staffs becoming overwhelmed
in times of crises. There was some evidence that this occurred during the disaster caused by
Alberto.

43


Re a ag one

Table D-19. Altamaha River at Charlotte CHRGI, Flood Stage 15 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)

Crest: 23.3 ft, am 07/16/94

Previous Flood of Record: 31.2 ft, 1/22/25

D-21

07/07/94 8.9 | Crest near 24 17th 12:45 pm
07/08/94 9.2 | Crest 24-25 17th 12:15 pm
07/09/94 9.4 | Crest 24-25 16th 12:25 pm
07/10/94 9.8 | Crest 24-25 16th 11:25 am
07/11/94 10.4 | Crest 24-25 16th 11:55 am
07/12/94 11.4 | Crest near 24 16th 11:15 am 7
07/13/94 16.3 | Crest near 24 16th 11:45 am
07/14/94 21.3 | Crest near 24 16th 11:50 am
07/15/94 23.0 | Crest near 24 16th 11:40 am
07/16/94 23.3 | Near crest...begin falling this evening | 10:50 am
07/17/94 22.6 | Crested yesterday...fall below FS 21st | 11:10 am



FINDING 2-5: Even though the SERFC area of responsibility has almost
complete WSR-88D coverage, the SERFC was not able to quantitatively use the
WSR-88D information in its forecasts. The capability to process WSR-88D
digital precipitation estimates would have added value to the hydrologic forecasts.

RECOMMENDATION 2-5:  Pre-AWIPS workstations must be deployed
immediately to the SERFC and other RFCs so the Stages II and III Precipitation
Processing can be performed and utilized in the forecasts.

The WSR-88D has known hardware and software problems that make it unreliable for archiving.
Although the Atlanta NWSFO did not detect a problem with their WSR-88D Levels 3 and 4
archiving (base and derived products) during Alberto, they encountered an unrecoverable error
in trying to retrieve the archived data after the event. There has only been limited success in
getting archived products from the Warner Robbins (near Macon, Georgia) WSR-88D, which
was the closest WSR-88D to the area of heavy precipitation.

FINDING 2-6: The Atlanta WSR-88D was not able to retrieve data from the
archive for a precipitation event that set historical records.

RECOMMENDATION 2-6: The potential for losing data, for all time, that
could be used for storm analysis, training, and calibration of hydrometeorologic
models and calibration of the WSR-88D dictates a requirement that there be a
prompt resolution of the problems with the archive media.

There were also problems acquiring data from associated Principle User Processors (PUP).
Associated PUPs provide access to WSR-88Ds that are not located at the NWS office and are
usually not owned by the NWS. The NWSFO at Birmingham, Alabama, noted a problem with
the number of products that can be sent from associated PUPs (e.g., Maxwell AFB) when there
is widespread precipitation. They had to reduce the number of Maxwell AFB products from 36
to 20 to get the subset of products in a timely manner.

FINDING 2-7: The WSR-88D was unable to provide all the products in the time
required when there was a large-scale precipitation event.

RECOMMENDATION 2-7: Develop methods to increase the number of
products that can be obtained by associated PUPs, especially for offices with
warning responsibilities.

2.2.2 LOCALLY ACQUIRED DATA
The SERFC reported a good flow of observed data from the NWS offices in its area. The storm
precipitation totals are included in Figure 1-4. The Atlanta NWSFO experienced difficulty in

getting data from cooperative observers because of the evacuation of some of the observers. The
Atlanta NWSFO used the sheriffs’ departments to get more reports. The cooperative observer

25


Tennessee 2

Alabama Georgia,

Americus
7] 27.61" Storm Total

"}

pul
g
—<
“

Precipitation (in)
oo) 8-12

ie by NWS Climate Center

Figure 1-4. Storm total precipitation during the period July 3-9, 1994 (Americus, GA:
27.61" storm total).


the modernization and make maximum use of technology components which are mature enough
to warrant deployment.

FINDING 3-3: The operational shift and training requirements, coupled with a large geographic
area of responsibility, limited the opportunity for the WCMs to interact with local users.
Consequently, the WCMs did not thoroughly coordinate with all the users in their County
Warning Area.

RECOMMENDATION 3-3: The NWS needs to develop an efficient strategy to maximize the
efficiency of the collective efforts of the WCMs and other staff members. A WCM team
approach should be considered whereby other Weather Forecast Office (WFO) and occasionally
RFC staff members are designated as liaisons with the state and local agencies involved in such
activities as emergency management, water resources, and public safety.

FINDING 3-4: At least one member of the emergency management community chose not to
be burdened with the numerous products sent via NOAA Weather Wire Service (NWWS) for
a neighboring state. As a result, critical forecasts and warnings for that county were not
received. NWWS users want to efficiently receive weather information that pertains only to
their jurisdictions.

RECOMMENDATION 3-4: Users need the ability on NWWS to parse only those hydrologic
products that apply to their areas of responsibility, e.g., a given county. The NWS should
require the use of generic codes on all NWS public hydrologic products until AWIPS is
implemented, and the WCMs should work with the users to insure that all necessary products
are being received.

FINDING 3-5: The NWS offices affected by Alberto were stressed to provide enough human
resources during the disaster to continuously utilize all information the WSR-88Ds had to offer.
It would have been virtually impossible for these offices to have provided the critical services
they did if they were staffed with any less employees.

RECOMMENDATION 3-5: The NWS should reassess its core-level staffing requirements
(going from five lead forecasters and five journeyman forecasters down to four lead forecasters
and four journeyman forecasters), especially for offices with multiple WSR-88Ds.

FINDING 3-6: The SH workload at the offices surveyed was quite extensive and typical of any
WFO. Despite the good effort put forth by the SHs, it was apparent that timely completion of
important hydrology-related duties could not always be accomplished. This will be compounded
in the future for SHs who support multiple hydrologic service areas.

AT


EXECUTIVE SUMMARY

Tropical Storm Alberto originated in Senegal on June 18, 1994, as a tropical wave. The
system became Tropical Depression One on June 30 at approximately 0600 Universal
Coordinated Time (UTC). On July 2 at about 0000 UTC, the depression strengthened in the
Gulf of Mexico near the Yucatan Peninsula to become Tropical Storm Alberto. When the
center made landfall near Destin, Florida, at 1500 UTC on July 3, Alberto was at its peak
intensity, 993 millibars and 55-knot winds. Winds then quickly subsided, and Alberto’s
central pressure rose rapidly.

After landfall, the motion of the storm slowed and precipitation increased. The storm moved
slowly through Alabama into Georgia, stalling just south of Atlanta. Over the next few days
it reversed its course and then looped back on its previous course before ultimately
dissipating. During that period it dumped copious amounts of rain across the area. Amounts
as high as 21.1 inches in 24 hours were observed at Americus, Georgia. The Weather
Surveillance Radar-1988 Doppler (WSR-88D) provided the forecasters with a very good
representation of the areal extent of the precipitation although it underestimated precipitation
amounts somewhat. This rainfall produced record and near-record flooding along the Flint,
Ocmulgee, Chattahoochee, Choctawhatchee, and Apalachicola Rivers. Overall, flash
flooding and flooding caused by the rainfall from Alberto took 33 lives, destroyed thousands
of homes (including some entire communities), forced approximately 50,000 people to be
evacuated, and caused property damage (including lost crops) estimated as high as
$750 million.

Based on the current technologies available to the National Weather Service (NWS) offices in
the area affected by Alberto, the offices in general performed their forecast and warning
functions in an exemplary manner. The NWS received high praise for its products and
services from all affected parties (emergency managers, the media, and the general public).
Throughout Georgia, Alabama, and Florida, the disaster survey team found a remarkably
universal degree of high regard.

The lack of negative comments may be attributed in part to the fact that external perceptions
and expectations of NWS’s present and future capabilities were quite limited relative to what
the NWS believes it can and should be able to do as‘a result of the modernization now
underway. Initial uncertainties regarding Alberto’s landfall, the failure to predict that the
storm would stall over Georgia instead of moving to the northeast, the Bainbridge forecast
discrepancy, and the relatively short lead-time of some flash flood warnings are all examples
of where users of NWS forecasts and products should, in the future, be able to expect a
more accurate and timely service.

ix


Table D-17.

Ocmulgee River at Abbeville ABBG1, Flood Stage 12 ft

Date Latest Forecast (ft) Issue Time (EDT)
Report (ft)
07/05/94 6.9 | Crest 12-13 14th 10:35 am |
07/05/94 Crest near 17 14th 3:30 pm
07/06/94 Crest near 20 13th 11:05 am
| 07/07/94 8.9 | Crest near 20 13th 12:45 pm
| 07/08/94 11.8 | Crest near 22-23 13th 12:15 pm
Ee 16.2 | Crest near 23 12th 12:25 pm |
07/10/94 21.3 | Crest near 23 11th 11:25 am |
07/11/94 23.1 | Near crest...begin falling this 11:55 am
afternoon
07/12/94 22.4 | Crested...now falling 11:15 am

Crest: E23.1 ft, am 07/11/94
New record level
Previous Flood of Record: 19.40 ft, 01/23/25

D-19


Table 2-1. Products related to Alberto issued by the NWSFO, NWSO, and WSO offices

OFFICE SPS FFA FFW FES FLW FLS RVS
Georgia Offices:

Atlanta (ATL) 3 13 16 18 18 95
Columbus (CSG) 41 W 15

Macon (MCN) 10 20 27

Alabama Offices:

Birmingham (BGM) a7 15 4 W 18 54 23
Montgomery (MGM) 20 3 rt

Florida Offices:

Melbourne (MLB) 2 9

Pensacola (PNS) 90 4 1

Tallahassee (TLH) 43 1 23

Totals 234 28 69 104 31 167 23

LEGEND: SPS - Special Weather Statement
FFA - Flash Flood Watch
FFW - Flash Flood Warming
FFS - Flash Flood Statement
FLW - Flood Waring
FLS - Flood Statement
RVS - River Statement

Flash flooding in Sumter County was aggravated by the overtopping and failure of many small,
unregulated earthen dams. According to the Georgia Department of Natural Resources (DNR),
Safe Dams Program, a total of 218 dams failed in Georgia during this event, of which 35 were
in Sumter County. Unregulated earthen dams are defined by Georgia DNR as small rural stock
ponds and do not fall under the state dam inspection program. These dams often fail when an
extreme rainfall event causes the outflow for the dam to exceed the spillway capacity of the dam.

Floodwaters swept many vehicles off roadways (two-thirds of the flood deaths here occurred in
vehicles) as motorists attempted to cross flooded roads and bridges while floodwaters were rising
rapidly. A number of homes were also flooded--and in a few cases swept away--by rapidly
rising flood waters, which resulted in two of the deaths.

NWSFO Atlanta had that area of Georgia which includes Sumter County under a Flash Flood
Watch (FFA) continuously beginning 4 p.m. July 3 through July 7. WSO Columbus, which has
CWA responsibility for Sumter County, issued the first Flash Flood Warning (FFW) for Sumter
County at 2:19 a.m. EDT on July 6. Flash flooding claimed its first victim in Sumter County
around midnight, and the majority of the deaths in this county occurred between midnight and
dawn on July 6.

30



TEAM 1 CONTACTS:

WSO Columbus (GA):
WSO Macon (GA):

Macon (GA):

Americus (GA):

Lake Blackshear Dam (GA):

Albany (GA):

Newton (GA):

Bainbridge (GA):

WSO Tallahassee (FL):

James Helms, Meteorologist in Charge

Gary Davey, Acting Officer in Charge;
Jim Boone

Gene Field, Deputy Director, Emergency
Management Agency, Macon and Bibb County

Randy Howard, Sumter County Sheriff and
Emergency Management Agency Director

Gene Ford, Power Commission;
Kelly Richardson, Chief Operator

Jim Bramble, Emergency Operations
Center/Emergency Management Agency for
Albany and Dougherty County

Jack Henderson, City Councilman

Jerri Slemmins, 911 Director;

Captain Tracy Horne, Emergency Medical
Technicians Training Officer;

Sam Griffin, publisher;

Frank Taylor, Jr., reporter;

Dr. Oscar Jackson, DDS

Paul Duval, Meteorologist in Charge

E2



Table 2-2. River basins that reached new floods of record and equaled/exceeded the 100-year
recurrence of floods
a

Basin number of locations number of locations
>=100 yr recurrence with new record flood

Ocmulgee (GA) 3 3

Chattahoochee (GA) 0 0

Flint (GA) 18 20

Alabama* 0 4

Apalachicola (GA) 0 1

Choctawhatchee (FL) 2 0

Totals 2B 30

* includes all affected basins in Alabama

routinely supply QPFs. Interestingly, an analysis of the forecasts indicates the lack of any clear
trend in the river forecasts issued. Some forecasts were very close to the observed crests several
days in advance; some forecasts were lower than the observed crest; and a few forecasts were
above the observed crests. Appendix D includes a chronological listing, by forecast point, of
the forecasts issued by SERFC during this event.

The destruction and human misery wrought by the floodwaters were enormous. A brief
summary of some of the major flood impacts is listed below.

Ocmulgee River - Macon, Georgia, was swamped by a record crest of 35.4 feet on July 7
(previous record was 28.00 feet on 11/29/48). The floodwaters overtopped and breached levees
at Macon and flooded the water treatment plant. Freshwater was not restored for nearly
3 weeks. Two major Interstate Highways (I-75 and I-16) were closed for approximately
36 hours due to the floodwaters and required traffic detours of more than 100 miles. Several
hundred homes were evacuated in Macon, most of which eventually flooded.

Flint River - Some of the most spectacular flooding occurred along the Flint River. The crest,
generally 20-25 feet above flood stage and 4-6 feet above the previous record crest (January
1925), wreaked havoc as it moved downstream and caused immense damage as well as the
evacuation of tens of thousands of people. Blackshear Dam, upstream of Albany, was
overwhelmed; and the high pool level forced the evacuation of residents in about 1,400 homes
around the lake (almost all of which were ultimately inundated) before the dam was overtopped
and breached. Albany suffered major flood damage after nearly one-third of its 76,000 residents
were evacuated. Further downstream, at Newton, nearly the entire town was flooded to depths
of 15-20 feet. After exceeding previous record flood levels as far downstream as Newton, the
Flint River at Bainbridge crested about 4 feet below record levels (although the measured
discharge of 108,000 cfs exceeded the previous record discharge of 101,000 cfs). Section 2.3.3
of this report further analyzes the Bainbridge forecast problem.

33