FIRE WEATHER FORECAST FORMAT EXPLANATION

SYNOPSIS - Brief description of weather features affecting forecast for next 36 hours.

VALID - Time period for forecast (today, tonight, tomorrow)

HEADLINE- A headline will be used anytime a RED FLAG WARNING or FIRE WEATHER

WATCH is in effect for a particular fire weather zone or a county in a fire weather zone. See example,

VALID    WX     TEMP     RH      WIND     POP/DUR/AMT      LAL     HI
=================================================================
NYZ072-076- NEW YORK METROPOLITAN AREA

...RED FLAG WARNING IN EFFECT TODAY...

TDY     CLR     96-100    5- 10      W 20-30        0/ 0 /0.00                 1          4
TNGT  CLR     52-56     70-75      W 14-18        0/ 0 /0.00                 1          4
SAT      CLR     68-72      31- 35    NE 5-10         0/ 0 /0.00                 1          4

MIXING HEIGHT     TRANSPORT WINDS     SMOKE DISPERSION
TDY 8000 FT                          W50 MPH                              GOOD
SAT 6000 FT                          NE10 MPH                             GOOD

ADDITIONAL INFORMATION...VERY LOW HUMIDITIES AND STRONG WINDS
COMBINED WITH VERY DRY FUELS WILL CAUSE CONDITIONS TO REACH RED
FLAG WARNING CRITERIA TODAY. PLEASE ADVISE THE APPROPRIATE
OFFICIALS IN THE FIELD OF THIS RED FLAG WARNING.

WX - Predominant weather feature; if the probability of precipitation is less than 50 percent the weather will be cloud coverage;
(CLR <2/10, SCT CLDS 2/10-5/10, BKN CLDS 6/10-9/10, OVC CLDS - 10/10)

TEMP - Temperature (F) - range forecast for daytime maximum and nighttime minimum

RH - Relative humidity (percent) - range forecast for daytime minimum and nighttime maximum

WIND - Range of average 12-hour wind speed (mph) and direction

POP/DUR/AMT - Probability of precipitation in percent/ duration - hours/ amount - inches

LAL - Lightning Activity Level - categories

  1. - no thunderstorms/lightning
  2. - few thunderstorms/ few lightning strikes
  3. - widely scattered thunderstorms/scattered strikes
  4. - scattered thunderstorms/numerous strikes
  5. - widespread thunderstorms/frequent strikes
  6. - dry lightning - sky condition and lightning at LAL 3 or higher, but no precipitation


HI - Haines Index - a stability index determined by combining the stability and moisture content of the lower atmosphere into a single number that correlates very well with large fire growth. Calculated near noon (18Z) for daytime and near midnight (06Z) for nighttime.

Haines Index potential for large fire growth:
(2 or 3 very low, 4 low, 5 moderate, 6 high).

MIXING HEIGHT - Height above the surface (feet) through which relatively vigorous mixing will take place due to convection.

TRANSPORT WINDS - Average wind speed (mph) and direction from surface to top of mixed layer.

SMOKE DISPERSION - categories - expressed in terms of mixing heights and transport winds. (POOR, FAIR, GOOD, VERY GOOD).

ADDITIONAL INFORMATION - Text space to include additional information such as reasoning to support a Fire Weather Watch/Red Flag Warning in a given zone.

LOCATION LIST - Provides mid-point single values for temperature, relative humidity, and wind for the listed representative location for each fire weather zone.