Pennsylvania Forest Fire Wardens Association

RedFlag Warning: This is a fire weather program which highlights the onset of critical weather conditions conducive to extensive wildfire occurrences.

A term used by fire-weather forecasters to call attention to limited weather conditions of particular importance that may result in extreme burning conditions. It is issued when it is an on-going event or the fire weather forecaster has a high degree of confidence that Red Flag criteria will occur within 24 hours of issuance. Red Flag criteria occurs whenever a geographical area has been in a dry spell for a week or two, or for a shorter period, if before spring green-up or after fall color, and the National Fire Danger Rating System (NFDRS) is high to extreme and the following forecast weather parameters are forecasted to met:

I. A sustained wind average ]5 mph or greater,

2. Relative humidity less than or equal to 25%, and

3. A temperature of greater than 75°F.

In some states, dry lightning and unstable air are criteria.

In Pennsylvania, the weather parameters are:

1, The afternoon and evening relative humidity levels are expected to fall to 25% or lower

2. and

3. The 20 foot sustained winds are expected to exceed 15 mph (13 knots) for at least 2 hours

In the past, Pennsylvania has also used an independent parameter based on fuel moisture. This parameter may be reinstituted again. It was:
1, Ten hour fuels must be at 8% moisture or less and expected to remain at that level for 2 or more days.

Red Flag (Fire Weather) Watch is used to alert the user to the possible development of a Red Flag event in the near future. This could be up to 72 hours in advance.

see current Red Flag Warnings