Heat Wave!

Wednesday morning update: strong easterlies (up to 30 kts) are pushing across western Washington aloft with very warm air with the easteriles. At the surface it is in the mid 40s...a few thousand feet aloft it is 15F warmer! Temperatures will surge this morning to amazing levels for November as the warm air mixes down.


Well, sort of. Today was considerably warmer than normal and tomorrow will be a revelation of warmth. Highs today ranged from 63F at Seattle under full sun to 65 at Boeing Field and 64F at North Bend. It was above 60F almost everywhere. Normal? Around 55F! And it is going to be much warmer tomorrow. And with a little wind thrown in at a special neighborhood!

Here is a graphic for the last month of average highs and lows and the observed temperatures at Sea-Tac:You can see today's unusual warmth, but averaging the highs and low over the entire month we really came very close to normal. So no complaints. La Nina cold doesn't start until the new year. Precipitation is another story--we were about two inches above normal (5.24 inches in the rain gauge). That is consistent with La Nina.

Now tomorrow is going to be a big step up in warmth. Why? We are developing an offshore difference in pressure (higher inland, lower offshore) and easterly winds are increasing aloft. Want the proof? Here are the winds aloft (and temperature) above north Seattle. Such flow brings warming as air is compressed as it sinks down on the western slopes of the Cascades. The increasing pressure difference and winds moving across the crest, will strengthen as they descend the "Stampede Gap" into the Enumclaw/Black Diamond/Maple Valley area--so things will get breezy there overnight. Here is the forecast winds for tomorrow AM:And really strong winds will be found over the western exit of the Strait of Juan de Fuca. This is a good example of something books often get wrong...usually the strongest winds are in the exits of gaps and Straits...not in their middle or where they are narrowest.

Back to warmth...here are the temperatures predicted by the local high-res computer model run at the UW. Wow! Temperatures in the upper 60s and lower 70s all over the place in western Washington. In fact, it is warmer west of the Cascades then to the east.


What about probcast? (www.probcast.com)--the super high tech probabilistic prediction system. This is exactly the kind of situation in which it does well. And it is going for 71F at Sea-Tac tomorrow--and from the map plenty more of that around the region.


Now I am not telling you to skip work tomorrow or playing hookie from school, but tomorrow will be glorious...sun, warmth, trees in full blaze of fall color. And the weekend? There may be some gaps...but rain will be back.