Wednesday, November 6, 2013

More Winds!

Another wind event will hit western Washington tomorrow, but it should not be as bad as last Saturday.   First, the horizontal pressure differences associated with this storm will not be as large....thus less winds.   Secondly,  a lot of the vulnerable branches have already been "pruned" by Saturday's blow and there are less leaves on the trees.

Here are the pressure forecasts from the latest runs of the UW WRF model for 10 AM and 4 PM tomorrow (Thursday).  The solid lines are lines of constant pressure, isobars.
At 10 AM, a small but serious low is immediately off of Vancouver Island....big pressure gradients and winds over the offshore waters.

 By 4 PM the low is over northern Whidbey Island.  The area of strong pressure gradient is mainly south of Seattle.  To get a big Seattle windstorm the low would have to move a bit farther northward....and there certainly is a possibility it could.

Next, lets look at the close up, high resolution forecasts from the same model.  These plots show near surface (10-m) gusts, wind vectors, and isobars.

By 7 AM tomorrow, it is blowing hard over NW Washington and particularly the waters stretching from Whidbey Island through the San Juans.  Blustery in Seattle (roughly 25-30 mph).

By 1 PM the low center is over the NW tip of the Olympic Peninsula, with VERY strong winds over the Pacific (50 knots plus!).  Still windy over the interior.

And at 10 PM as the low goes by, strong westerly winds will develop in the Strait of Juan de Fuca.  A westerly wind surge.

And there will be rain!  Take a look at the 24h rainfall ending at  4 AM Friday. Some mountain locations could get over 2.5 inches.  Major rainshadow near Yakima.  You know why?   Winds will be generally northwesterly after the system moves through, so the Yakima area will be downstream of the substantial southern Cascades.


 Mukilteo Storm Dinner Talk at Ivar's

A reminder...I will be talking about historic wind events at Ivar's Mukilteo during a special anniversary dinner on Thursday night.  Roughly 10 years ago their restaurant was destroyed by a Strait of Juan de Fuca wind event and the facility was rebuilt on a weather and storm theme.   For more information check here.  Limited to 40 people--only about 8 places left.


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