Hot Weather & Fire Danger Message National Weather Service, Seattle WA 29 July 2015
Hot Weather & Fire Danger Message
Hot weather is expected in the interior through Saturday evening.
The Fire Danger will be high, especially in the mountains, through Saturday evening.
Heat is building across the interior of western Washington, especially from Seattle southward. The hot weather is likely to peak on Friday, but only slight cooling is expected on Saturday. Conditions are expected to cool a bit more on Sunday followed by more significant cooling starting early next week.
A heat advisory is in effect for the Seattle Metropolitan Area, the Tacoma Area, the East Puget Sound Lowlands, and the Southwest Interior from noon Thursday through Saturday evening.
A Red Flag Warning is in effect for the Cascades and the Olympic mountains above 2000 feet until 10 PM Friday for a very dry and somewhat unstable air mass.
High temperatures from about Seattle southward in the interior will reach the lower to mid 90s on Thursday, and mainly in the mid to upper 90s on Friday. Temperatures on Saturday will only cool slightly, reaching the mid 80s to lower 90s. Overnight lows will only cool into the 50s to mid 60s, with the warmest low temperatures in the urban heat island areas of Seattle, Bellevue, and Tacoma.
Relative humidity values will be quite low in the mountains; the low humidity will be accompanied by somewhat unstable conditions aloft. The combination of dry air, dry fuels and somewhat unstable condtions will result in the increased risk of rapid growth of new or existing brush or wild fires. Even in the lowlands, it will be quite dry during the afternoon and evening hours with relative humidity falling to below 25 percent at times.
Confidence is high that hot conditions will affect the central and south interior of western Washington Thursday through Saturday.
Confidence is high that the humidity will be low and conditions aloft will be somewhat unstable.
Confidence is moderate that conditions will cool somewhat on Sunday and will cool more substantially Sunday night through Wednesday.