Wildfire danger: Red Flag Warning posted for Puget Sound area

Wildfire danger: Red Flag Warning posted for Puget Sound area »Play Video
Areas shaded in red are covered by the Red Flag Warning. Areas in green are covered by a Flash Flood Watch and a Red Flag Warning. (National Weather Service map)
SEATTLE -- Fire weather forecasters with the National Weather Service are sounding the alert for all firefighters across much of Western Washington to be prepared for potential wildfires this weekend as thunderstorms are expected to form.

A Red Flag Warning is now in effect through Sunday evening for much of the region, including the Seattle and Puget Sound Metro areas, the foothills and the mountains.

A Red Flag Warning is issued when for the combination of dry fuels and incoming weather that would be an aggravating factor to creating wildfires, be it dry humidity, lightning, and/or strong winds that would help quickly spread any wildfire.

In this particular case, it’s lightning that is the biggest threat.

An approaching area of low pressure from California will bring unstable air to our region, starting to the south Friday afternoon, then spreading across the area Friday night. As the low continues its slow approach to the Washington Coast for Sunday, conditions will be ripe for thunderstorm development over the Cascades and Olympics during the entire period.

Meanwhile, upper level winds are expected to be out of the east/southeast that could push thunderstorms off the Cascades into the lowlands where lightning can also spark fires. This overall pattern would be a somewhat similar situation to the thunderstorms that roamed across our region last Wednesday.

The threat for the lowlands abates Sunday night as the low moves away.

Luckily we don't have an east wind situation which gives very low humidity and adds strong wind to the equation. But the lightning along is worth the worry and individual thunderstorm cells can bring gusty, erratic winds to new or any existing fires.

These fire weather warnings are intended mostly as a heads up for the firefighting community, giving fire companies a heads up that they might be very busy this weekend.

"It's time to have all hands on deck," said Andy Haner with the National Weather Service.

For the public, it serves as a reminder of how dry conditions are and to be particularly careful with anything that could spark a fire.