We received several angry emails this week when the Red Flag Warning for predicting severe fire weather was issued. Each message contained the same refrain - aren't you overreacting since it just rained last week?
A Red Flag Warning is issued by the United States National Weather Service, not FIRESafe MARIN. All Red Flag Warnings are related to predicted weather and fuel moistures, and weather and fuel conditions must meet specific criteria. A small amount of rainfall during the summer and fall months usually not increase live or dead fuel moistures significantly. Current knowledge of fuels and fire behavior tells us that live fuel moistures can still at a critical level, and dead fuels will dry to their pre-rainfall level within 10 hours during a low humidity wind event.
Any Red Flag Warning wind event issued for Marin has the potential to cause rapid growth and extreme fire behavior if any wildfires start.
These weather conditions resulted in humidities as low as 10%,a nd wind gusts of 50MPH in Marin yesterday, and a 4,000 acre wildfire erupted in the east bay. The only thing separating Marin from destructive fire like that was an ignition source...