For the last few days the weather over the Northwest has been warm and sunny...nearly perfect for outdoor activities. The only negative of the warm, dry weather is fire..and if you look at this evening's visible satellite image you can see the smoke from two large fires over northern Oregon. Plus lots of low clouds along the coast, with a sliver entering the Strait of Juan de Fuca.
Here is a summary of the temperatures of the last 4 weeks versus the normal highs and lows. Pretty normal pattern, with periods of warmer and cooler than normal temps--average out the period, it all is close to normal. There is a good lesson in this--daily temperatures are rarely normal!
A major transition is now occurring and you can expect MUCH cooler weather and the return of some showers for the next 4-5 days. A weak front is now approaching the coast, and the thermal trough, which has been sitting over or just to the east of the western lowlands is rapidly moving eastward. The pressure gradient has turned onshore and cooler air will be moving in overnight. But this will not be like a strong marine push, the decline will be gradual overnight and the first half of Thursday. Here are the pressure patterns for today and tomorrow ... very different indeed.
Aloft the temperatures will be around 20F cooler tomorrow ... you will notice it.
And as the front moves through and the coastal winds turn westerly, a Puget Sound convergence zone will form. As a result the models are predicting a band of precipitation over central Puget Sound late tomorrow afternoon and into the evening (see graphic). Lets see if they are right!
Finally, there have been some ultra-high temps over the inland portions of California, with the warmth extending into Oregon (see graphic). Over 105F in the central valley and over 110F over the SE part of the state. And I might note that nearby Medford, Oregon got to 105F and Redmond, OR a hot 100F! In contrast, the NE U.S. is now cool, with temps in the 70s.