**FIRE WEATHER OPERATING PLAN**

**WEATHER FORECAST OFFICE (WFO)**

**MORRISTOWN, TN**

**January 2005**

George Mathews, Meteorologist in Charge

David Hotz, Fire Weather Program Leader

Tim Doyle, Assistant Fire Weather Program Leader

**I.** Introduction

**How the Fire Weather Program fits into the NWS/OM Mission\...**

Weather is one of the most significant factors in determining the
severity of wildland fires. The spread rate and intensity of fires is
directly related to the wind speed, temperature and relative humidity.
Climatic conditions, such as long term drought also play a major role in
the number and intensity of wildfires. Accurate and timely weather
information is vital to the planning and execution of strategies for
suppressing wildfires. An accurate weather forecast can mean life or
death to a fire fighter and is also critical in protecting forest and
range lands as well as the increasing number of homes in the wildland
urban interface.

The Fire Weather Program is an integral part of the overall operations
of the National Weather Service (NWS) at Morristown, Tennessee. This
operating plan describes the fire weather products and services provided
by the Morristown, Tennessee Weather Forecast Office (WFO). The
operating plan has been developed in cooperation with the primary user
groups: Cherokee National Forest, Great Smoky Mountain National Park,
Jefferson/Washington National Forest, Nantahala National Forest,
Tennessee Division of Forestry, Virginia Division of Forestry and North
Carolina Division of Forestry.

The products and services provided to the above land management agencies
are geared for three main reasons: (1) contain and minimize the
destructive potential of wildfires to life, property and natural
resources, (2) reduce the adverse impact of smoke from prescribe burns
near populated areas, and (3) aid in the management of prescribe burns.
The operating plan has been prepared in accordance with the "National
Agreement For Meteorological Services in Support of Agencies with Land
Management and Fire Protection Responsibilities" concluded in March 2002
and included in Appendix A.

**II.** Organizational Directory

National Weather Service

Weather Forecast Office

5974 Commerce Blvd.

Morristown, TN 37814

[Meteorologist in Charge (MIC)]{.underline}

**George Mathews**

[Fire Weather Program Leader]{.underline}

**David Hotz**

**Tim Doyle** - Assistant

The Forecast Office is staffed 24 hours a day, 7 days a week throughout
the year.

Public and aviation weather forecasters are available for special
forecasts or questions and

consultation, conditions permitting.

[Telephone Numbers:]{.underline}

Fire Weather coordination - 1-800-697-0075 or 423-586-6429

Administrative - 423-586-6429

Fax - 423-586-9336

Internet site (home-page) - [www.srh.noaa.gov/mrx]{.underline}

NOAA Weather Radio Frequencies:

Tri-Cities (WXK-47) - 162.55 MHZ

Knoxville (WXK-46) - 162.475 MHZ

Chattanooga (WXK-48) - 162.55 MHZ

**III.** Operational Program

The WFO Morristown, Tennessee provides three basic forecast products
which support fire management and fire control operations in the states
of Tennessee, Virginia and North Carolina. These three products are the
routine fire weather planning forecast or pre-suppression forecast
(FWF), National Fire Danger Rating System (NFDRS) forecast (FWM), and
spot forecast.

As a cooperative effort between the forestry community and the weather
service, periodic review and modification to the operational program
will be done to meet the changing needs of the users. Any major changes
to the program will result in accompanied revision of the operating
plan.

**A. Normal Fire Weather Season**

The prescribe burn season across the WFO typical runs from mid-February
to early-May, and generally the greatest threat for wildfire occurs from
mid-October to mid-December due

to the fallen leaves and normally dry weather.

**B. Types of Fire Weather Forecasts and Issuance times**

1\. Routine morning Fire Weather Planning Forecast (FWF) - 6:00 am (LST)

2\. Seasonal (Mid-February to Mid-May) afternoon FWF - 4:00 pm (LST)

3\. Spot Forecasts for wildfires -- as needed from both Federal and
State Foresters.

4\. Spot Forecasts for prescribed burns -- as needed from **Federal
agencies only**.

5\. NFDRS forecast -- upon arrival of the Fire Weather Observation (FWO)
from WIMS.

6\. Updated or revised FWF - as conditions warrant (refer to section
III-F).

**C. Forecast area for the Fire Weather Forecast**

The Fire Weather Forecast will always be broken down into 8 different
fire zones. The different sections are list as follows: (please refer to
the Fire Weather Forecast map in the appendix).

**Fire Weather Forecast Zones\...**

1\. Jefferson-George Washington National Forest/Virginia Forestry
District 6

2\. Northern Cherokee National Forest

3\. Great Smoky Mountain National Park

4\. Southern Cherokee National Forest

5\. Nantahala National Forest/North Carolina Forestry

6\. Tennessee State Forestry District 1

7\. Tennessee State Forestry District 2

8\. Tennessee State Forestry District 3

**D. Forecast Methology**

Forecasts are made to reflect the worst expected conditions in terms of
fire management within the fire weather forecast zone during a given
period. For example, the daytime forecast will depict the hottest,
driest, and windiest conditions that are expected. On occasion, the Fire
Weather Forecast may differ from the general public forecast, which
emphasizes prevailing conditions during the period and is usually aimed
at more populated urban or developed parts of the area.

Since the Fire Weather Forecast can not reflect all the local variations
in the weather, a spot forecast should be requested whenever local
effects are suspected of creating difficult fire management conditions.

Over mountainous terrain, weather conditions can vary greatly from site
to site within the same fire weather zone. Routine Fire Weather Forecast
for mountain zones (Cherokee National Forest, Great Smoky Mountain
National Park, and Nantahala National Forest) will be aimed at a target
elevation. The target elevation for the Jefferson National Forest,
Northern Cherokee National Forest and Smoky Mountain National Park will
be around 2500 feet.

For the Southern Cherokee and Nantahala National Forests the target
elevation will be near 1500 feet.

As a general rule in mountainous terrain, those sites above the target
elevation and/or north facing slopes will have a lower temperature and
higher relative humidities than forecast. Conversely, sites at lower
elevations and/or south facing slopes will average warmer and drier than
the forecast.

**E. Morning-Afternoon Forecast Format and Content of Routine FWF**

The Fire Weather Planning Forecast format was developed in coordination
with the Federal and State forestry community. The morning FWF will
contain a forecast for three periods: Today, Tonight, and Tomorrow. The
afternoon FWF will contain a forecast of four periods: Tonight,
Tomorrow, Tomorrow night, and next day.

The "Today" forecast covers the period from the issuance time to sunset.
"Tonight" is from sunset until sunrise tomorrow, then the "Tomorrow"
forecast covers from sunrise to sunset.

An extended forecast will be added to each forecast group for both the
morning and afternoon FWF.

**Contents of the Fire Weather Planning Forecast (FWF)** ‑

**Headline -** A headline will be used to emphasize a fire weather
watch, red flag warning, or any specific weather change that will
greatly affect fire suppression.

**Discussion** ‑ This is a brief description of weather systems and
their effect on Tennessee valley and Southern Appalachians for the
duration of the forecasts. Significant weather features, such as strong
wind, fronts, or low humidity will be discussed in this section.
Significant changes to wind, humidity and precipitation should be
emphasized first.

**Cloud Cover** - The following are the different cloud forecasts and

their associated definitions.

**[Cloud Cover Definitions]{.underline}**

CLEAR \...\...\...\...\...\...\.... less than 1/10 opaque clouds

PCLDY\...\...\...\...\...\...\..... (Partly Cloudy) 4/10 to 7/10 opaque
clouds

MCLDY\...\...\...\...\...\...\.... (Mostly Cloudy) 8/10 to 9/10 opaque
clouds

CLOUDY \...\...\...\...\...\.... more than 9/10 opaque clouds

**TEMP (Temperature)** and **RH % (Percent Humidity)** ‑ Temperature and
relative humidity are very important fire weather parameters,
specifically relative humidity. We will forecast high temperatures and
lowest relative humidity for the daytime forecasts and lowest
temperature and highest relative humidity for the nighttime forecast.
Factors such as elevation, aspect (ie. south facing slope) and ground
cover cause temperatures to vary several degrees in a small area.

**WIND-AM(MPH)** and **WIND-PM(MPH)** ‑ Wind is perhaps the most
important weather element to fire fighters. In the fire weather forecast
the daytime wind prediction will be broken into two periods ‑ AM and PM.
This is to allow forecasters to take into account diurnal variations in
speed which frequently occur, resulting in smaller ranges. Speed values
represent a one‑minute average in miles an hour, 20 feet above the
ground in exposed areas. Direction is expressed using eight compass
points (ie. N, NE, E, etc.). Wind gusts are indicated in the forecast if
greater than ten miles an hour over the sustained speed. If the wind is
forecast to be less than 5 mph, then a forecast of Light and Variable
will be given (abbreviation LGT/VRB).

**Precipitation type, amount and duration** ‑ A prediction of
precipitation type will be given when expected. Forecasters need to be
alert to possibility of lightning hazards, giving thunderstorms priority
over other types. An estimate of the amount of rainfall and duration
will be included in the forecast when precipitation is expected (POP 20
percent or greater). Amounts will be estimated to the hundredths inch
and duration in hour(s) that the precipitation is expected to fall.

In the case of frozen precipitation, a water equivalent amount will be
given in the forecast.

The precipitation amount should be similar to your QPF forecasts
(approximately basin average).

**[PRECIP TYPE Definitions]{.underline}**

NONE No Precipitation

DRIZL Drizzle/Misty Precipitation

SNOW/RAIN Mix of Snow and Rain

FRZ RAIN Freezing Rain - Rain that freezes on exposed surfaces.

RAIN Liquid Precipitation

TSHWR Showers with Thunder

**CHANCE PRECIP (%)** - Probability numbers in the forecast represent
the expected occurrence of 0.01 inch or more of precipitation at any
point in the fire weather zone during a forecast period.

**PRECIP BEGIN and PRECIP END** - Since time of occurrence can be very
helpful to the forestry community, a forecast of Precip Begin and Precip
End will be given. The time will correlate with local standard time
(LST) (Examples: 4 AM, 11 PM). If the precipitation is expected to
continue into the next time period, then **CONTINUE** will be included.

**LASI - Lower Atmospheric Stability Index** **(LASI)** is an indicator
of stability resulting from measurement of temperature and moisture
differences in the lower portion of the atmosphere. Large temperature
differences just above the surface create an unstable environment and
have been associated with extreme fire behavior.

The **LASI** is included in the Fire Weather Forecast mainly as a safety
reference, providing firefighters with information on atmospheric
stability.

The lower atmospheric stability index used in the Tennessee forecast is
identical to the one developed by Donald Haines (sometimes referred to
as the **\_Haines Index\_**), with the exception of the lowest height
measurement. The newer mandatory level at 925 millibars is used to make
calculations easier. For lower elevations:

\(A\) 925 mb T ‑ 850 mb T Factor Values

less than 4 degrees C 1

4 to 8 degrees C 2

greater than or equal to 8 deg C 3

\(B\) 850 mb T ‑ 850 mb Td

less than 6 degrees C 1

6 to 10 degrees C 2

greater than or equal to 10 deg C 3

Add the factor values (A + B) to obtain the LASI. For higher elevations
of east Tennessee use 850 mb T ‑ 700 mb T to obtain the \_A\_ value.

**LASI** **CLASS OF DAY**

2 or 3 very low

4 low

5 moderate

6 high

A forecast of LASI will be given in both the Today and Tomorrow
forecast. This forecast will reflect the expected LASI during the
afternoon or peak heating of the day.

**MIXING HGT (FT-MSL) and TRANSPORT WND (MPH)** ‑ A projected height of
vertical mixing of air and suspended particles will be forecast for the
day periods in feet above **Mean Sea Level (MSL)**. It is valid for use
during the afternoon hours when temperature nears the predicted maximum.
Transport wind speed is a predicted average wind in miles an hour in the
layer below the mixing height. This parameter is also valid for the
afternoon hours.

**REMARKS** - The remarks section will allow the forecaster to include
any specifics about the forecast, such as timing of fronts, that is
deemed crucial for the fire land management agencies.

**FORECAST FOR DAYS 3 THROUGH 7** ‑ A prediction of general weather
conditions expected to occur in each fire weather zone group during the
next 5 days.

**F. Updated Fire Weather Planning Forecast**

The Fire Weather Planning Forecast will be updated when the expected
weather changes significantly from what was predicted in the routine
forecast. The decision to issue a fire weather update will be based on
the effect the weather change has on the fire behavior and the level of
fire danger in the state(s). An update may be issued at any time of day
and using the following guidelines:

1\. If precipitation was not mentioned in the previous forecast

and looks likely or if it was forecast as being predominant

and now looks as if it will not occur or remain isolated an

update should be issued.

2\. An update should be considered when a front and it's

associated wind shift is much delayed or arrives sooner than

expected.

3\. An update should be considered whenever the wind speed is much

stronger or lighter than previously expected. Differences of

10 to 15 miles an hour in most cases are significant and may

also apply to gustiness. If the wind direction differs by two

or more compass points (more than 45 degrees) an update may be

needed if the prevailing wind speed is 15 miles an hour or

more.

4\. When relative humidity drops to very low levels (30 percent or

less) and differs by more than 15 percent from the morning

forecast an update should be considered, or if the relative

humidity remains high and low levels had been previously

forecast.

**G. Spot Forecast**

The National Weather Service at Morristown, TN will provide, on request,
a specialized forecast for existing wildfires or prescribe burns for the
federal forests and parks. The NWS will provide spot forecast for the
state forester for wildfires, if needed for public safety. The spot
forecast is a site‑specific, localized forecast of weather, wind
(including slope and valley winds in mountainous terrain), maximum and
minimum temperature and humidity. Duration time of the forecast is
generally for 24 hours. The land management agency is encouraged to use
the NWS Web-based SPOT program. If the NWS SPOT program is unavailable,
then you may use local fax

or phone to request a SPOT forecast.

When possible, information items 1 through 11 on WS form D‑1 should
accompany a request for this type of information. It is particularly
important to issue a revised forecast promptly in the event of a
previously un-forecast or mistimed wind shift or wind increase and
precipitation.

Recent observations at or near the fire site should be obtained before
issuing a spot forecast.

It is advised that hourly observations begin 24 hours before the
request. If an observation is not provided then the user of the forecast
should be informed that the accuracy of a forecast depends on this
information.

The forecaster should attempt to provide response to the land management
agency within 30 minutes of a request, time permitting. If the response
time will be longer, then the user should be informed at the time of the
request.

**Example of a Spot Forecast**

SPOT FORECAST FOR (location or name of burn)

NATIONAL WEATHER SERVICE MORRISTOWN TENNESSEE

TIME-DATE (Example: 800 AM EST TUE APR 16 2004)

IF CONDITIONS BECOME UN-REPRESENTIVE, CONTACT THE NATIONAL WEATHER
SERVICE.

\...HEADLINE..(If a fire weather watch or red flag warning is in effect,
a headline is required - otherwise, a headline is recommended or every
issuance.)

DISCUSSION\...

FIRST PERIOD

SKY/WEATHER\...\.....

TEMPERATURE\...\.....

RH\...\...\...\...\.....

WIND\...\...\...\...\...(specify the wind level)

MIXING HEIGHT\...\...(maximum height in Mean Sea Level)

TRANSPORT WINDS\....(MPH)

SECOND PERIOD

SKY/WEATHER\...\.....

TEMPERATURE\...\.....

RH\...\...\...\...\.....

WIND\...\...\...\...\...(specify the wind level)

MIXING HEIGHT\...\...(maximum height in Mean Sea Level)

TRANSPORT WINDS\....(MPH)

THIRD PERIOD

SKY/WEATHER\...\.....

TEMPERATURE\...\.....

RH\...\...\...\...\.....

WIND\...\...\...\...\...(specify the wind level)

MIXING HEIGHT\...\...(maximum height in Mean Sea Level)

TRANSPORT WINDS\....(MPH)

FORECASTER\...(optional)

**H. National Fire Danger Rating System (NFDRS) Forecast**

NFDRS forecast is issued for selected RAWS observation site. These
forecasts are used as input for the National Fire Danger Rating System
which generates indices which are used in determining fire danger for a
given area and to plan for the necessary human and other resources to
fight wildfires.

The NFDRS is a means for forest managers to evaluate fire danger. It
consists of a complex model of fuel and weather parameters input on a
daily basis to obtain a numeric output that indicates the severity of
fire danger in an area representative of the input values.

Fire weather observation sites used for NFDRS input usually represent
the worst conditions in terms of dryness in a given forest or area. The
ideal site would be one on a south or west facing slope without
obstructions to wind. Parameters measured include weather and fuel
moisture, with observation time around 1 pm LST daily. The observed data
is entered into WIMS (Weather Information and Management System) by the
forestry agency, then is received by NWS under the product header
FWOMRX.

Utilizing the current weather as a starting point, the weather
forecaster will enter the predicted 24 hour weather parameters for the
observation point. Usually within the next hour, the fire manager will
be able to retrieve fire danger indices from WIMS based on the forecast
provided. This information processed with predicted weather through 24
hours gives land managers an estimate of fire severity in their area of
responsibility. The site forecast will be issued under the product
header FWMMRX (WMO FNUS84).

The weather service is obligated to make a forecast for each observation
that is received from WIMS.

**I. Red Flag Warning and Fire Weather Watch (RFWMRX)**

A red flag warning is issued when forecast conditions, together with
existing environmental conditions, could result in extreme fire behavior
or, as in the case of lightning with brief rain, high winds and low
humidity, extensive fire starts within the next 24 hours. This product
will be issued under the product (RFWMRX). A highlight of the Red Flag
Warning should be included within the routine fire weather forecast.

Conditions which warrant the issuance of a red flag warning are the
following:

1\. Strong wind with low humidity, generally 25 miles an hour wind

speeds or higher with less than 25 percent relative humidity.

2\. or Lightning risk with brief light rains (Dry lightning, which

seldom occurs in our area).

NWS Morristown, TN will coordinate the issuance of a Fire Weather

Watch or Red Flag Warning with the associated land management

agency. We will ask for fire danger and areas of concern.

A fire weather watch is issued when red flag conditions are

expected within the next 72 hours. The National Weather

Service will use the same critical weather conditions as

mentioned for the Red Flag Warning.

**Example of a Red Flag Warning\...**

RED FLAG WARNING

NATIONAL WEATHER SERVICE MORRISTOWN TN

1245 PM EST SUN MAY 10, 2004

TNZ039-070-051645-

\...RED FLAG WARNING FOR EAST TENNESSEE THIS AFTERNOON AND

MONDAY FOR LOW RELATIVE HUMIDITIES AND HIGH WINDS\...

FIRE WEATHER COUNTIES INCLUDED IN THIS WARNING ARE:

HAMBLEN AND JEFFERSON

DISCUSSION\...

A RED FLAG WARNING IS IN EFFECT FOR ALL OF EAST TENNESSEE FOR

THE REMAINDER OF THIS AFTERNOON AND CONTINUING THROUGH MONDAY.

VERY LOW RELATIVE HUMIDITY WITH READINGS DROPPING TO 15 TO 20

PERCENT AND STRONG WEST TO SOUTHWEST WIND BETWEEN 20 AND 30 MPH HAVE
RAISED THE POTENTIAL FOR WILDFIRES TO EXTREME LEVELS.

SEVERAL MONTHS OF BELOW NORMAL PRECIPITATION HAVE ALSO

CONTRIBUTED TO THE VERY VOLATILE SITUATION.

A DEVELOPING STORM SYSTEM ACROSS THE CENTRAL PLAINS WILL BRING A COLD
FRONT INTO TENNESSEE MONDAY AFTERNOON. DUE TO THE LIMITED MOISTURE WITH
THIS SYSTEM, LITTLE IF ANY PRECIPITATION IS

EXPECTED. HOWEVER, AFTER THE FRONTAL PASSAGE, A DROP IN WIND

SPEEDS AND AN INCREASE IN RELATIVE HUMIDITY ARE EXPECTED WHICH

WILL AID IN LESSENING THE FIRE DANGER ACROSS THE AREA.

**J. Fire Danger Statements**

In cooperation with fire control agencies, the WFO Morristown, TN can
issue special statements to inform the general public about critical
fire danger. These statements may contain information

from land management agencies about burning bans and preparedness
actions as well as weather information.

Special statements may be broadcast to the public on NOAA weather radio
stations throughout Tennessee, Southwest Virginia and extreme southwest
North Carolina.

***IV.* Special Services**

Special meteorological services meet the needs of land management
agencies who occasionally have unique requirements for weather support,
such as large wildfires. This support often requires travel of weather
service personnel. Agencies requesting these services usually pay for
travel and per diem for the meteorologist and for any overtime which may
be required.

Special services include on-site meteorological support for wildfires,
weather observer training, weather station visitations requested by user
agencies, and participation in user agency training activities.

**A. Incident Meteorologist (IMET)**

These are specialized trained meteorologists to work with wildfire
suppression foresters on the site of the fire to provide fire weather
support. They will utilize Air Transportable Mobile Units (ATMU) to give
them local observations and meteorological forecast guidance at the
wildfire site. IMETs are most likely to be requested during large and
complex fire fighting operations which may extend over a period of
several days or possibly weeks. The fire community is responsible for
requesting IMETs.

The Fire Weather Program Manager or the Meteorologist in Charge at the
NWS at Morristown, Tennessee should also be advised of the need for an
ATMU and IMET.

**Mobile Unit Services**

A modularized Air Transportable Mobile Unit (ATMU) is a collection of
weather instruments and computer equipment which can be transported
quickly to a wildfire or other emergency by air or ground freight. These
units are stored at federal fire caches around the country and are
available as a resource for an IMET for use in emergencies requiring
weather support. Request for an ATMU must be called in along with a
request for an Incident Meteorologist (IMET) to a regional USDA Forest
Service Office.

The requesting agency is responsible for coordinating transportation of
the ATMU and IMET to and from an incident. Provisions must be made at
the site for sheltering the equipment and IMET as well as a telephone
and electrical equipment.

**B. Fire Weather Training**

National Weather Service fire weather meteorologists are available to
assist Land Management agencies with training at fire behavior courses
(S290, S390, NFDRS, etc.).

Requests for assistance should be in writing to:

Meteorologist in Charge

National Weather Service

5974 Commerce Blvd.

Morristown, TN 37814

**C. Severe Weather Reports**

Severe weather reports are extremely important and helpful to the staff
at NWS Morristown, TN during severe weather events. Our most important
responsibility is to warn the public of impending weather hazards. Very
little information is available from the remote mountainous areas of
Eastern Tennessee, Southwest Virginia and western North Carolina. These
areas coincide with the areas of concern by land management and fire
control agencies.

If severe weather is occurring, please relay the information immediately
to the NWS staff at Morristown, TN so they can promptly warn the general
public. Call in reports to phone number 423-586-6429 or any other
Morristown, TN weather office number.

The National Weather Service will gladly provide free training about
severe weather to groups interested in helping us with this task. The
NWS program through which groups of people are trained to recognize and
report severe weather is known as SKYWARN.

What to Report:

1\. Tornadoes, Funnel Clouds, Waterspouts

2\. Winds 58 mph and over or wind damage

3\. Hail - dime size diameter or greater

4\. River flooding or flash flooding of creeks

5\. Snow - 4 inches or more

6\. Hazardous ice accumulations on roads,

trees, or power lines.

If damage is detected from a storm on following days, the information is
still needed for 'Storm Data', a publication issued by the NWS that
keeps a historical record by state of

severe weather occurrences. It also helps the forecaster to assess past
storms and improve detection probability and forecast techniques for
future storms. Please call the NWS Forecast

Office during administrative hours, if possible, with this information.

**V. Communications**

Fire weather forecasts issued by the National Weather Service in
Morristown, Tennessee are stored locally and then transmitted to a
centralized computer located in Washington, DC. The

centralized computer has the ability to communicate with the Forest
Service's Weather Information Management System (WIMS), allowing fire
managers with computer access into WIMS to obtain weather forecasts for
any location in the United States. This method of communication is used
primarily by the USDA Forest Service and the National Park Service.

The National Weather Service in Morristown, Tennessee will include the
Fire Weather Forecast within our Internet home-page.

**APPENDICES**

**Table of Contents**

A. National Agreement for Meteorological Services

B. Fire Weather Forecast Zones Map

C. Forecasts and statements Examples

D. Weather Service form D-1 (Spot Forecast Requests)