**Hydrometeorological Analysis and Support Function**

**at the Southeast River Forecast Center**

Jack S. Bushong**,** Judith Stokes Bradberry, and Kent D. Frantz

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*AUTHORS:* Meteorologists, Hydrometeorological Analysis and Support
Function, Southeast River Forecast Center, National Weather Service,
Peachtree City, Georgia 30269.

*REFERENCE: Proceedings of the 2001 Georgia Water Resources Conference*,
held March 26-27, 2001, at the University of Georgia. Kathryn J.
Hatcher, Editor, Institute of Ecology, The University of Georgia,
Athens, Georgia.

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**Abstract.** In the late 1980s, the National Weather Service (NWS)
launched its ten year, 4.5 billion dollar Modernization and
Restructuring (MAR) program to take advantage of rapidly advancing
scientific and computer technologies. The implementation of MAR is
complete and has succeeded in modernizing the hydrometeorological
operations of the NWS. As a result of MAR, all 13 River Forecast Centers
(RFC) across the U.S. restructured their operations and upgraded
computer technology. The RFCs have extended their hours into the evening
and nearly doubled their staffs, which included the hiring of three
meteorologists at each RFC. These meteorologists have become part of a
new function at RFCs, known as the Hydrometeorological Analysis and
Support (HAS) function, to manage the greatly increased flow of
hydrometeorological data for input into the hydrologic models. The HAS
forecaster is primarily responsible for the production of the
Quantitative Precipitation Forecast (QPF), the verification activities
associated with the QPF, the comparison and quality control of radar and
rain gage data, and the production of hydrometeorological discussions.

INTRODUCTION

The Southeast River Forecast Center (SERFC), with a responsibility for
river and flood forecasting for the Southeastern United States and
Puerto Rico, has been incorporating 24-hour Quantitative Precipitation
Forecast (QPF) for the Carolinas and Virginia since the late 1980s, and
for the rest of the Southeast U.S. since 1995. Presently,
Hydrometeorological Analysis and Support (HAS) forecasters receive QPF
guidance from the NWS' Hydrometeorological Prediction Center (HPC),
located in Washington, D.C. The HAS forecaster makes modifications to
this QPF guidance, if needed, and prepares it for use in the hydrologic
model.

The HAS forecaster uses several tools to quality

control rain gage data that is used as input in the hydrologic model. In
the near future, the hydrologic forecasters will have the choice of
using either rain gage-adjusted radar data or strictly rain gage data in
the hydrologic model. This radar data is analyzed and quality-controlled
by the HAS forecaster and is available on the Internet.

In addition, the HAS forecaster assimilates information describing the
current and future hydrometeorological situations and issues a daily
hydrometeorological discussion in text and graphical formats.

This paper will describe the most important duties of the HAS forecaster
and discuss the tools he or she uses to analyze hydrometeorological data
that supports the SERFC mission. An Internet link will be supplied for
each product discussed.

ADVANCED WEATHER INTERACTIVE PROCESSING SYSTEM

The Advanced Weather Interactive Processing System (AWIPS) is the final
piece to the modernized National Weather Service office and became
operational in the late 1990s. Prior to AWIPS, forecasters had to use
different computers to view all the weather products available. AWIPS
now brings all weather products to one workstation and can also overlay
different products on the same map. For instance, a forecaster can view
a satellite picture overlaid with meteorological model data.

The SERFC has seven Unix-based AWIPS workstations, each of which
includes two graphical interactive displays and one text display. Most
of the software used by the SERFC is run on the two graphical
interactive displays. Text messages such as forecasts, statements, and
warnings are viewed or edited on the text display.

The software run on AWIPS includes the Stage3 application, an
interactive radar display program, the Interactive Forecast Program
(IFP), which is the interactive river forecast model application, and
the D2D (Display 2-Dimensional), which is a viewer of satellite, radar,
and meteorological model data.

STAGE 3/RFC-WIDE

The SERFC is normally opened daily from 6 a.m. to 11 p.m. local time. If
flooding is imminent or occurring, the office hours are extended to
cover 24-hour operations. The HAS forecaster is typically the first
person to report for duty each morning.

The first duty of the HAS forecaster is to run Stage 3 application.
Stage 3 is a one-hour precipitation estimate based on a mosaic of the 28
WSR-88D radars. The precipitation is adjusted using ground-based rain
gages (Figure 1). Stage 3 is so named because of the three steps, or
stages, to get the final product. The first stage is a one-hour
precipitation estimate based on the reflectivity of each individual
radar. The second stage is the adjustment of the one-hour precipitation
with ground-based rain gages. Finally, the third stage is the quality
control of the radar mosaic by the HAS forecaster. In Stage 3, hourly
estimates are mosaicked onto a 4 KM grid. Quality control steps may
include the elimination of radar returns due to ground clutter,
anomalous propagation, or faulty rain gages.

The products from Stage 3 are available on the Internet at:

http://www.srh.noaa.gov/atr/qpfvsmap.htm

The RFC-wide application will replace the Stage 3 application in the
summer of 2001. RFC-wide will provide several improvements over the
Stage 3 program, the most important being the use of radar climatology
to determine areas of reduced accuracy due to beam blockage of each
radar (Breidenbach et al., 2000).

Mean areal precipitation derived from Stage3/RFC-wide output (MAPX) may
be used as input in the hydrologic model. It is expected that the higher
the temporal and spatial resolution in the rainfall input, the more
accurate the river forecast (Stellman, Fuelberg and Garza et al., 1998).

Currently, mean areal precipitation derived from gage data (MAP) (Figure
2) is the primary rainfall input in the hydrologic model. MAP products
are available on the Internet at:

http://www.srh.noaa.gov/atr/qpfvsmap.htm.

QUANTITATIVE PRECIPITATION FORECASTING

In 2000, the SERFC assumed the primary responsibility of Quantitative
Precipitation Forecasting (QPF) from the local NWS Weather Forecast
Offices (WFOs).

The HAS forecaster uses several tools and procedures in determining QPF.
Traditional meteorological models are viewed on D2D, and experimental
models are available to the forecaster on the Internet. Once the HAS
forecaster has reviewed all the products related to the QPF generation,
he or she may coordinate the QPF forecast with the local WFOs, HPC, and
adjacent River Forecast Centers.

Using the AWIPS software called NMAP (National Centers for Environmental
Prediction-AWIPS Map), SERFC HAS forecasters are able to view the
national QPF forecasts prepared by HPC (Figure 3). These precipitation
forecasts are used as guidance and can be edited by the HAS forecaster.
Once the editing is complete, NMAP outputs the QPF for a 24-hour period
in 6-hour intervals in both text and graphical form. The QPF is
routinely prepared twice a day and is available on the Internet at:

http://www.srh.noaa.gov/atr/qpfpage.html

Updated QPF products are normally available by 9 a.m. and 9 p.m. daily.

QPF VERIFICATION METHODS

Locally-produced software is used to verify the SERFC QPF forecasts.
Many statistics are computed. However, the one used most often is the
Mean Absolute Error (MAE). In this case, MAE is defined as:

MAE =![](media/image1.wmf){width="1.7013888888888888in"
height="0.5631944444444444in"}

where,

QFP = Quantitative Precipitation Forecast for a particular basin

MAP= Mean Areal Precipitation for a particular basin

N = Number of basins

HPC also runs a QPF verification program for each RFC which compares the
Mean Absolute Error of the RFC and HPC QPF with the QPF computed by
several meteorological models (Figure 4).

A link to the HPC Verification Unit and QPF versus MAP graphics are
available daily on the SERFC QPF web page.

HYDROMETEOROLOGICAL DISCUSSION

The HAS forecaster leads a daily weather briefing each morning. This
briefing focuses on hydrometeorological concerns in the SERFC forecast
area.

Once the SERFC hydrologists have produced and disseminated the river
forecasts through AWIPS and the Internet, they brief the HAS forecaster
on current river conditions. The HAS forecaster may also view the river
conditions graphics and hydrographs that are available on the SERFC home
page at:

http://www.srh.noaa.gov/atr

The river conditions graphics are updated each day at around 12:10 p.m.
and are also updated when forecasts are revised.

The HAS forecaster prepares a Hydrometeorological Outlook map using the
Unix-based Atlas-GIS software (Figure 5). A text version of the
Hydrometeorological Discussion (HMD) is then composed and disseminated.
These graphical and text HMD products are available at:
http://www.srh.noaa.gov/atr/hmd/default.html

by 1:00 p.m. each day.

SUMMARY AND OUTLOOK

Since 1994, when the three HAS forecasters arrived at the SERFC, their
primary task has been the development of the HAS function. The goals for
the HAS forecaster conceived in the NWS Modernization plan of the late
1980s have been met. More use of the Internet, conference calls, and a
briefing tool called FX-Connect will allow the HAS forecasters to get
specific hydrometeorological information out to our customers such as
local WFOs, the emergency management community, and other water
resources agencies.

The HAS forecasters will continue to develop and improve the duties
described in this paper. They will also expand on an outreach program
and implement a river flood watch program.

SUMMARY OF SERFC INTERNET LINKS

**SERFC Home Page**

http://www.srh.noaa.gov/atr

**Mean Areal Precipitation and Stage 3 Products**

http://www.srh.noaa.gov/atr/qpfvsmap.htm

**Quantitative Precipitation Forecast**

http://www.srh.noaa.gov/atr/qpfvsmap.htm

**Hydrometeorological Discussion**

http://www.srh.noaa.gov/atr/hmd/default.html

**Advanced Hydrological Prediction Services**

http://www.srh.noaa.gov/atr/ahps/default.html

**Ensemble Streamflow Prediction**

http://www.srh.noaa.gov/atr/esp/html/esp.htm

For specific Internet addresses, please e-mail jack.bushong@noaa.gov.

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height="4.281944444444444in"}

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height="4.159722222222222in"}

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height="4.289583333333334in"}

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height="7.334027777777778in"}

ACKNOWLEDGMENTS

Thanks to Reggina Garza, Senior Hydrologist; and Nene Robertson,
Hydrologic Technician, for their help in the completion of this paper.

LITERATURE CITED

Breidenbach, J.P., 2000. RFC-wide Multisensor Precipitation Estimator,
5.

Stellman, K., H. Fuelberg, R. Garza, 1998. Utilizing Radar Data to
Improve Streamflow Forecasts, 1-3.

U.S. Dept. of Commerce, 1997: Correspondence Course\--Operations of the
NWS Hydrologic Services Program. Lesson 2, Hydrologic Services Program
at National Weather Service Field Offices, 30.