National Weather Service United States Department of Commerce

Storm Impacting the Northwest U.S.; Fire Weather Conditions in Southern California; Severe Weather in the South

A Pacific storm is bringing areas of low elevation rain, moderate to heavy mountain snow, and high winds to the Northwest. Strong Santa Ana winds and very dry conditions are producing elevated to critical fire weather conditions in southern California. Isolated strong to severe thunderstorms are possible through early Wednesday morning across parts of northeast Texas into western Tennessee. Read More >

Fire Weather Planning Forecast for the State of Hawai`i

 

Map of Fire Weather Zones

The primary use of the daily Fire Weather Planning Forecast is for fire pre-suppression activities and planning. Issued daily at 5:30 AM HST, this product includes:

  1. Discussion including meteorological features influencing the weather statewide.
  2. Forecasts:
    1. Sky cover and weather
      Common sky cover terms
      Day Only Day or Night Predominant Sky Condition
      Cloudy Cloudy 8/8 Opaque Clouds
      Mostly Cloudy, or
      Considerable Cloudiness
      Mostly Cloudy, or
      Considerable Cloudiness
      6/8 to 7/8 Opaque Clouds
      Partly Sunny Partly Cloudy 3/8 to 5/8 Opaque Clouds
      Mostly Sunny Mostly Clear 1/8 to 2/8 Opaque Clouds
      Sunny Clear 0/8 Opaque Clouds
      Weather qualifiers for rain or thunderstorm likelihood
      Qualifying term Areal
      coverage term
      Probability of precipitation (POP)
      Slight chance (or none) Isolated (or none) 10% or less
      Slight chance Isolated 20%
      Chance Scattered 30%, 40%, 50%
      Likely Numerous 60%, 70%
      none none 80%, 90%, 100%
    2. Temperature - Forecast maximum for daytime; minimum for nighttime.
    3. Humidity - Forecast minimum relative humidity for daytime; maximum relative humidity for nighttime.
    4. Wind - Forecast direction and speed during the most hazardous part of the day, and generally at night. Maximum gusts and erratic winds and/or wind shifts will be given, where necessary.
  3. Smoke dispersal (mixing height/inversion level) and transport wind
  4. 3 to 5 day extended forecast.

Red Flag Warning - issued when meteorological and environmental conditions are expected to result in extreme fire behavior within 24 hours. Red Flag Warnings will be issued as a separate product and as a headline in the daily or amended daily Fire Weather Planning Forecast.


Spot Forecasts for Wildfires and Prescribed Burns

The spot forecast is a site-specific, localized forecast for wildfires and prescribed burns. Eye-level winds are generally preferred in the spot forecast since on-site observers will report eye level winds which will also be experienced by the on-site fire suppression team.

The spot forecast includes:

  1. Discussion of the meteorological factors affecting the particular site during the forecast period.
  2. Forecasts:
    1. Sky cover and weather at the site.
      Sky cover terms
      Day Only Day or Night Predominant Sky Condition
      Cloudy Cloudy 8/8 Opaque Clouds
      Mostly Cloudy, or
      Considerable Cloudiness
      Mostly Cloudy, or
      Considerable Cloudiness
      6/8 to 7/8 Opaque Clouds
      Partly Sunny Partly Cloudy 3/8 to 5/8 Opaque Clouds
      Mostly Sunny Mostly Clear 1/8 to 2/8 Opaque Clouds
      Sunny Clear 0/8 Opaque Clouds
      Qualifiers for rain or thunderstorm
      Qualifying term Equivalent areal
      coverage term
      Equivalent
      probability of precipitation (POP)
      Slight chance (or none) Isolated (or none) 10% or less
      Slight chance Isolated 20%
      Chance Scattered 30%, 40%, 50%
      Likely Numerous 60%, 70%
      none none 80%, 90%, 100%
    2. Temperature - Forecast maximum for daytime, minimum for nighttime at the site.
    3. Humidity - Forecast minimum relative humidity for daytime; maximum relative humidity for nighttime at the site.
    4. Wind - Forecast direction and speed of the wind during the most hazardous part of the day, and generally at night. The time of maximum gusts and erratic winds and/or wind shifts will be given.
  3. Mixing Height (inversion level) and transport wind may be included.
  4. Outlook for the following day, or the following night and next day.