Storm Prediction Center - Fire Weather Products

Fire Weather Products

The Storm Prediction Center also is responsible for issuing fire weather outlooks (FWD) for the continental United States. These outlooks are a guidance product for local, state, and federal government agencies, including local National Weather Service offices, in forecasting the potential for wildfires. The outlooks issued are for day 1, day 2, and days 3–8. The day 1 product is issued at 4:00 a.m. Central time and is updated at 1700Z, and is valid from 1200Z to 1200Z the following day. The day 2 outlook is issued at 1000Z and is updated at 2000Z for the forecast period of 1200Z to 1200Z the following day. The day 3–8 outlook is issued at 2200Z and is valid for days 3–8.

There are four types of Fire Weather Outlook areas: "See Text", a "Critical Fire Weather Area for Wind and Relative Humidity", an "Extremely Critical Fire Weather Area for Extreme Conditions of Wind and Relative Humidity", and a "Critical Fire Weather Area for Dry Thunderstorms". The outlook type depends on forecast weather conditions, severity of the predicted threat, and local climatology of a forecast region. "See Text" is a label on the map for pointing out areas where fire potential is great enough to pose a limited threat, but not enough to warrant a critical area, similar to "See Text" areas in convective outlooks. Critical Fire Weather Areas for Wind and Relative Humidity are typically issued when strong winds (>20 mph) and low Relative Humidity are expected to occur where dried fuels exist, similar to a slight or moderate risk of severe weather. Critical Fire Weather Areas for Dry Thunderstorms are typically issued when widespread or numerous thunderstorms producing little wetting rain (<0.10 in) are expected to occur where dried fuels exist. Extremely Critical Fire Weather Areas for Wind and Relative Humidity are issued when very strong winds and very low RH are expected to occur with very dry fuels. Extremely Critical areas are rarely issued, similar to the very low frequency of high risk areas in convective outlooks (see List of SPC extremely critical fire days).