Up, down, up, down…interesting 2nd half of summer eh? Something for everyone.
Major marine push already in progress at 5pm. I see the North Bend-PDX gradient is 7.3 mbs already! That’s good even for 20 mph southerly wind in midwinter, so we should see a rapid cooldown this evening. Dramatic cooling in the upper atmosphere in the next 24 hours two as a sharp trough moves through the Northwest tomorrow & Wednesday. It should suffice to say that tomorrow will be a VERY good day for windsurfing in the Gorge (I used to to that before marriage/kids/home improvement etc…). Gusts to 50 mph from The Dalles to Arlington are likely. The marine layer quickly thickens to well above pass elevations by midday too.
Rain is unlikely, but I think central/eastside metro area will see trace-.03" or so each of the next 2 mornings.
Then, it’s back to "September" heat. It’s clear on the maps this afternoon that this weekends warmup will be a "fallish" pattern, not summer (same end result). The sharp thermal trough develops out that the coast instead of in the valley Friday. And surface high pressure builds over the Rockies (their first cool airmass since spring). The combination will bring the first widespread early fall/late summer easterly wind to the Gorge, Cascades, Coast Range and metro area Friday & Saturday. So enjoy the cool weather before the heat returns…Mark