Today will be the warmest day of the heatwave in the interior of the West, with coolness already occurring over some coastal areas.
Yesterday’s highs (shown below) ranged from more than 100F east of the Cascade Peak, to close to 100F in the Willamette Valley, to the mid to upper 80s around Puget Sound and to the 60s on the South Coast of Oregon. Warmer than usual than most areas, but some records have fallen.
Today, temperatures are warmer overhead… and in fact, temperatures around 5000 ft at the radiosonde site in Quillayute (UIL), on WA’s north coast, are close to a record for the day – not every record records of time, daily records (see below). (dot shows today’s temperature and red line is date).
Today is warmer in some places and cooler in others. Below is the temperature difference at noon compared to the same time yesterday. Warmer on Puget Sound, similar to Willamette Valley, but cooler along the Coasts south of Washington and Oregon.
Why is it cooler along the coast? Because clouds and cool air are moving up the coast, as seen in recent satellite images. This is forced by the reduced pressure inside.
The latest forecasts for Seattle show that today is the warmest day, but temperatures will stay mild for the next few days.
The situation in eastern Washington can only be described as extreme. Check out the situation at Pasco in the Tri-Cities. Scary. The high will hit 112F on Friday.
I’ve been studying heat waves in the Northwest for decades, and this is an animal that’s out of the ordinary.
Why different? Because the warmth associated with a wide high pressure peak of the loft is only slowly waning and moving eastward. As a result, cool sea air will move very slowly inland west of Oregon and Washington over the next few days.
The long-term forecast suggests a sustained cooling in the coming week.
