Spot Forecasts

 

 

There may be times when a grass or a forest fire is taking place so that a Spot Forecast may be necessary. The NWS can do a Spot Forecast for a Federal Agency when a Prescribed Burn or Wild Fire is taking place. A Spot Forecast can be done for a State Commission when they are working with a Federal Agency or a Wild Fire event is occurring.

It is imperative that as many observations as possible be received from the area that requires a spot forecast. This feature will greatly help to improve the accuracy of the forecast. A Spot Forecast would require the forecaster to estimate mixing heights, transport winds , temperature, surface wind, humidity, expected weather, cloud cover, and possibly rainfall amounts at 2-3 hour increments.

Current technology on the World Wide Web has allowed the National Weather Service to utilize the Web Based Spot Forecast from Western Region.

Based on the Web Based Spot Forecast concept. The Fire Weather Customer will do the following: (Assuming the Southern Region Server is properly functioning.)

If the Southern Region Server is down then the faxed form for the old method would be done.

The following information would be filled out on form D-1 for a Spot Forecast.

 

  1. Name of the Wild Fire or Prescribed Burn project
  2. Control Agency making the request
  3. Time and date of the said request
  4. Size of the fire or project in acres as well as elevation
  5. Type of vegetation that is being burned
  6. Exposure of fire (whether its on a hill or incline and Aspect)
  7. Whether its a ground fire or crown fire (tree top to tree top)
  8. Weather conditions...
      Weather conditions at the fire from a nearby station or observer with a weather kit:
    • 20 foot wind direction and speed
    • Dry/wet bulb temperatures
    • Relative humidity and dewpoint
    • Any close showers or storms

The forecast section with a table format will need to be filled with the following information:

  1. The Weather Synopsis/Extended Forecast
  2. Forecast material 3 periods at 1-3 hour intervals...for today...tonight...with a general outlook for the the next day. Could be altered some depending on customer needs.
  3. Temperatures
  4. Relative Humidity
  5. Chance of Wetting Rains
  6. Mixing Heights/Transport Winds
  7. Sky Conditions
  8. Surface Winds (20 foot per recent agreement with Fire Agencies)
  9. Stagnation Index...Stability Index...Vent Index...Dispersion

 

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General Spot Information

There are two types of Spot Forecast Products(commonly referred to as "Spots"). The first one is issued to support land management personnel for activities associated with Prescribed Burns. The other is issued to support fire suppression activities of on-going Wild Fires. The main difference between the two is that the format and content of a Spot Forecast for a wildfire is standardized nationally, while the format for the Spot Forecast for a prescribed burn is determined by the local users and will vary from office to office.

Before any Spot Forecast is issued the requesting agency should provide information about the location, topography, fuel type(s), elevation(s), size, ignition time, and a contact name(s) and telephone/fax numbers of the responsible land management personnel. Also ,representative observations at or near, the site of the planned Prescribed Burn or Wild Fire should be available to the responsible WFO prior to the issuance of the Spot Forecast by the web. In the case of a Wild Fire or a prolong burn, updated observations and information should be provided to the NWS during the course of the event. Spots will be updated whenever they become, or expected to become unrepresentative of the current forecast.

The general policy of providing Spot Forcasts is established by the local NWS offices and the local customers. The specific contents, issuance frequency, means of communication, and other details of distribution will be determined by local customers and NWS personnel at the time of the customer's request for spot information. Spot Forecasts will include specific weather information giving into account the various parameters in the incident area.

Critical weather element thresholds for the Spot Forecast will be determined by fire behavior analyst or other fuels/fire behavior expert who will define the range of wind, relative humidity, and any other factors which may cause significant changes to fire behavior. In the case of a Prescribed Burn, these thresholds are often defined in the "Burn Plan", which is normally developed and approved well before a Spot Forecast is requested. In most cases, such information can be obtained from the on-site requester.

Spot Forecasts may be sent to the requester through the mutually agreed upon distribution method. Requesters may communicate via a cell phone. In some cases, Spot Forecasts can be requested through a local "Fire or Emergency Dispatch" system. In other cases the fax (which is the most common method in Mississippi) may be the method to transmit...if the Southern Region Internet Server is down.

FNUS 74 KJAN DDHHMM FWSJAN

SPOT FORECAST FOR (LOCATION OF NAME OF WILDFIRE AND REQUESTING CUSTOMER...ie USFS) ISSUED BY THE NATIONAL WEATHER SERVICE JACKSON, MS TIME-DATE (OCT 4, 2006)

VALID UNTIL <8 HOURS AFTER ISSUANCE>

IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT YOUR NATIONAL WEATHER SERVICE

.HEADLINE...(IF A REDFLAG WARNING/FIRE WEATHER WATCH (JANRFWJAN)) A HEADLINE IS MANDATORY. OTHERWISE A HEADLINE SHOULD BE ADDED AT EVERY ISSUANCE. EX. SPOT FORECAST FOR (NAME OF WILDFIRE)

.DISCUSSION...BRIEF WEATHER SUMMERY AFFECTING FIRE OPERATIONS

.PERIODS (1-3 HOUR INTERVALS FOR TODAY INTO THIS EVENING IF NEEDED INTERVALS FOLLOWED BY AN EXTENDED PERIOD FOR OVERNIGHT AND TOMORROW) or it could be put in a national standard format for three 12 hour periods for today...tonight and tommorrow depending on the customer or IMET.

 

    THE FOLLOWING CATEGORIES WILL BE INCLUDED:
  • SKY/WEATHER
  • TEMPERATURE
  • HUMIDITY
  • WIND...(20 foot level per recent agreement with fire agencies)
  • OPTIONAL ELEMENTS...SUCH AT STAG INDEX...VENT INDEX...DISPERSION (MIXING HEIGHTS...TRANSPORT WINDS ETC (AS REQUIRED BY OUR AREA CUSTOMERS OR VISITING INCIDENT METEOROLOGISTS...WHICH MAY BE FROM ANOTHER PART OF THE COUNTRY).

Spot Forecasts Products for Prescribed Burns

Spot forecasts will be prepared in a format requested by the local customer which can be in graphical or tabular form. In our forecast area we use the tabular format, which may contain any of the following elements as requested by our customers; brief weather discussions, forecast weather, surface winds (including wind shifts), maximum/minimum temperatures and humidity. Upon customer request, other weather elements such as transport winds, mixing heights, stag index, chance of wetting rains. These elements are put into 2-3 hour increments for today through early this evening...depending on customer needs with an extended outlook for overnight and tommorrow. Since Spots are generally for small geographical areas. Areal weather descriptors (such as scattered showers, isolated showers,etc) should not be used. The timing of significant events is important and in the case of wind shifts, extreme critical. Wind forecasts should clearly indicate the level of the wind forecast (i.e. eye level, 20-ft level).

EXAMPLES OF THE 2 TYPES OF WEB BASED SPOT FORECASTS

 

EXAMPLE OF A SPOT FORECAST FOR A PRESCRIBED BURN or a WILD FIRE SPOT

  

FNUS 74 KJAN DDHHMM

FWSJAN

 

SPOT FORECAST FOR 4 MILES NE OF OVETT,MS...USFS

ISSUED BY THE NATIONAL WEATHER SERVICE JACKSON,MS 915 AM JANUARY 9, 2003

VALID UNTIL 515 PM JANUARY 9, 2007

IF CONDITIONS BECOME UNREPRESENTATIVE CONTACT YOUR NATIONAL WEATHER SERVICE

SPOT FORECAST FOR THE TIGER CREEK DRAINAGE PRESCRIBED BURN

DISCUSSION...BRIEF DISCUSSION AFFECTING FIRE OPERATIONS.

TIME...2-3 hour intervals affecting the customer desired time period.

SKY/WEATHER...specifies cloud cover or type of weather expected for the 2 to 3 hour intervals.

TEMP...specifies temps for the 2 to 3 hour intervals.

WINDSPEED (20FT) specifies the surface wind 20 feet above the ground or above tree tops at 1 to 3 hour intervals.

PROBABILITY OF PRECIPITATION...for 1 to 3 hour periods

DISPERSION INDEX for Stagnation Index...Mixing Height...Transport Winds...500 meter Temps etc for 1 to 3 hour intervals.

 

EXTENDED FORECAST (FOR 12-24 HOUR PERIOD) SKY/WEATHER...HIGH/LOW TEMPS...HIGH LOW HUMIDITIES...WINDS...REMARKS.

 

  1. Go to the fire weather section of the website and make a Spot Forecast Request.
  2. The customer would fill out the necessary Spot Forecast Form provided...giving information on the location of the Prescribed Burn or Wildfire in progress.
  3. The request would be alarmed on our computer under JANSTQJAN and the Spot Forecast would be created on the web browser at the Spot Forecast Section of the home page...then sent back to the web.
  4. The fire weather section of the website will update...informing the customer that the product is ready...where our forestry customer would retrieve the product.
  5. The customer can give us valuable feedback or any questions related to the product.
  6. It is important to inform the office when the Spot Forecast is not current with the current conditions of the burn in progress.
  7. There will be a map showing the location of the Spot Forecast and the Status of the product (whether it is pending or completed).
  8. The product would also be sent into our computing system of the NWS Gateway under JANFWSJAN...if the Spot Forecast is for Wild Fire Conditions.
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