Tomorrow's Windstorm in Four Acts

 Each atmospheric "play" is different and according to high-resolution forecast models, I can describe the four "acts" that will unfold tomorrow.

The main protagonist of this drama is strong, but small, low pressure center that will move northward up our coast. 

Note to local media:  not a bomb cyclone. 😕

Below is a view of the low at 4 PM Friday (the lines are isobars of sea level pressure, the color shading shows low-level temperature.)

Nice looking low, with a central pressure of 981 hPa.

Act 1:  1 AM Friday Morning

The forecast maps, with sea level pressure and near-surface winds (shading), are shown below.

As the low approaches, the pressure differences across the region will increase, with lower pressure towards the Pacific.  Easterly winds, particularly in east-west gaps, are apparent. The forecast map below predicts strong winds exiting the Fraser River Valley and then heading across Bellingham, and the San Juans, with strong easterly flow over the western portion of the Fraser River Valley.

Downslope easterly winds are developing along the western slopes of the Cascades and pushing towards Kent and south Seattle.  Winds picking up around the western end of State Rt. 2.  

Act 2.    7 AM Friday. The Games Afoot

Southeasterly winds are increasing on the coast and the easterly winds hitting Seattle to Kent are increasing with some gusts to 30-35 mph.  Far weaker than Tuesday evening, but enough to get folks nervous.

Intermission

Act 3.  4 PM Friday. Crescendo 

This is what the audience was waiting for.   With the offshore low making its closest approach, winds along the coast speed up considerably, with gusts reaching 50-75 mph.   Some power outages along the coast.  Over the lowlands of western Washington, winds turn southerly, with gusts to 30-35 mph around Seattle and 30-45 mph over northwest Washington.

Act 4.  10 PM Friday. Denouement  

As the low center pulls away, the wind rapidly weakens along the coast but stays gusty around the Strait of Georgia and NW Washington.

I hope you enjoyed the drama.