Precipitation Types and Details

 

  1. Rain- General or patchy liquid precipitation- not showery and usually in a stable or neutral temperature atmosphere...small and medium sized water drops
  2. Drizzle (DRZL)- General or patchy liquid precipitation in a stable or neutral atmosphere...very small water droplets appear to float in the atmosphere
  3. Freezing Rain/Drizzle (Frzg Rain/DRZL)- Liquid precipitation that freezes upon contact with ground, surfaces or vegetation
  4. Sleet (SLT)- Precipitation in the form of almost clear grains or ice pellets,often mixed with rain or freezing rain
  5. Snow- General or patchy flakes of crystalline precipitation usually not showery
  6. Snow Flurries (SNOW FLRYS)- Showery flakes or small white grains that rarely accumulate
  7. Showers (SHWRS) - Medium to large drops that usually begin or end abruptly - no thunder heard
  8. Thundershowers (TSHWRS) - Same as Showers but with thunder
  9. Thunderstorms (TSTMS) - Heavy or violent downpour of large water drops with strong gusty winds, lightning strikes, and small hail
  10. Severe Thunderstorm (SVR TSTM) - Violent downpour of large waterdrops, frequent lightning, wind gusts to 58 MPH or greater, and/or hailstones 1 inch in diameter or larger.

 

PRECIPITATION PROBABILITY

 

  1. No precipitation expected (Chances 5% or less).
  2. Isolated (ISOLD) - Precipitation chance 10 to 20%.
  3. Slight Chance (SLGT CHC) - Precipitation chance 10 to 20%.
  4. Chance (CHC) - Precipitation chance 30 to 50%.
  5. Likely (LKLY) - Precipitation chance 60 to 70%.
  6. Unqualified precipitation types- chances are 80 to 100%.

 

PRECIPITATION DURATION


Duration will be in hours for each of the three periods usually forecast in these ranges: 1 hr or less, 1-3 hrs, 2-4 hrs, 3-5 hrs, 4-6 hrs, and over 6 hrs.

PRECIPITATION AMOUNTS


Forecasts will pertain to average precipitation liquid volume expected over the zone (I.E. 0.50-0.75 inches), while widespread general precipitation tends to be more uniform over a square area the size of a forecast zone. Amounts with shower activity will vary considerably. During daylight time the periods are today (7AM-7PM), tonight (7PM-7AM), tomorrow (7AM-7PM). During standard time, the periods shift to: (6 AM-6PM).

Precipitation amounts will vary by different categories, since it is difficult to pinpoint an exact amount of rain over a given forestry zone.

  1. .10 inch
  2. .10 to less than .25 inch
  3. .25 to less than .50 inch
  4. .50 to less than 1 inch
  5. 1 inch or more



Any amounts significantly over one inch will be explained in the remarks section of the Fire Weather Forecast for each zone.

 

 

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