This server will be decommissioned on May 30, 2019. See https://www.weather.gov/media/notification/scn19-17pr_migration.pdf for details. You should update your bookmarks now. This page's new url is https://www.weather.gov/gum/fireweatherhelp.
Fire Weather Watch/Red Flag Warning Criteria
Specific conditions must be met for a Fire Weather Watch and/or a Red Flag Warning to be issued. These conditions are as follows:
1. KBDI greater that or equal to 600, and
2. Two minute ASOS winds greater than or equal to 17 kts (20 mph), or 20 foot winds greater than or equal to 14 kts (16 mph), and
3. Minimum relative humidity of less than 60% in one or more observations, and
4. Low 10-hr fuel moisture, typical less than 13.
5. Monthly precipitation less than two inches with a decrease and/or cessations of percolation (dew) can signal the onset of the fire season. Forecaster judgment must be used in the watch/warning decision making process.