A Red Flag Warning has been issued for Sammamish, Issaquah, and much of western Washington due to a forecast of dry thunderstorms that could bring lightning, according to the National Weather Service – Seattle. A Red Flag Warning means that critical fire weather conditions are either occuring now, or will shortly. A combination of strong winds, low relative humidity and warm temperatures will create explosive fire growth potential.
The Red Flag Warning will be in effect from 2 a.m. to 11 p.m. Saturday. Dry thunderstorms are possible late Friday night through Saturday evening.
According to the National Weather Service:
AN UPPER LOW OFFSHORE WILL APPROACH THE REGION THROUGH TONIGHT AND WILL MOVE INTO OREGON ON SATURDAY. THE LOW PRESSURE SYSTEM WILL THEN MOVE SOUTHEAST TOWARD NEVADA ON SUNDAY. THIS SYSTEM IS EXPECTED TO SPREAD INSTABILITY AND SOME UPPER LEVEL MOISTURE ACROSS THE AREA TONIGHT THROUGH SATURDAY NIGHT.
WHILE THE MOISTURE IS RATHER LIMITED...THERE WILL BE ENOUGH FOR A RISK OF ISOLATED DRY THUNDERSTORMS OVER PORTIONS OF THE AREA. THE DRYNESS LEVELS OF THE DEAD FUELS...INCLUDING GRASSES...BRUSH AND DEAD MATERIAL IN THE FORESTS AS WELL AS BUG KILL ARE AT OR NEAR RECORD DRYNESS LEVELS...WHICH WOULD MAKE THEM VERY RECEPTIVE TO FIRE STARTS FROM LIGHTNING.
* THUNDERSTORMS WINDS...DUE TO THE HIGH BASED NATURE OF THE STORMS THE WINDS SHOULD BE LIMITED...HOWEVER GUSTY WINDS ARE ALWAYS A THREAT WHEN THUNDERSTORMS ARE IN THE VICINITY.
* IMPACTS...WITH THE CURRENT FUEL CONDITIONS AS THEY ARE...ANY LIGHTNING WOULD BE EFFICIENT AT STARTING FIRES.