I had originally planned to work on this post last night during the Seahawks/49ers game, but there simply weren’t any boring parts where I could divert my attention from the game and to my computer. From start to finish, it was one of the best football games I’ve ever seen, period. I’m thankful that the Seahawks are heading into their bye week… I’m thoroughly “footballed-out” for the time being!
After an October that was the coldest on record for many locations around the Pacific Northwest, we’ve witnessed one of the quietest starts to November on record. Both Seattle and Portland saw no measurable precipitation during the 14 days from 10/26 to 11/8, which is one of the longest “storm season” dry spells for either city. Dr. Joe Zagrodnik (a UW Ph.D candidate while I was there who is now a post-doctoral researcher at WSU) put together a cool graphic showing all dry streaks of at least 10 days from 10/1 to 2/28 (or 2/29 during a leap year), and you’ll see that only a few years have had dry spells of 14 days or greater during the mid-October to late February period.
Seattle just hit 10 days in a row without measurable precipitation. Assuming it stays dry through next week, this streak will be one of the longest November dry spells in the Sea-Tac record. Only recent precedent is a 21-day dry run in December 1985. #wawx pic.twitter.com/QzOAAWFBNK
— Joe Zagrodnik (@joejoezz) November 5, 2019
There are no signs that we’ll transition to the typical, stormy November that we all know and love within the next ten days, but we’ll at least see a few weak/moderate systems Friday and Sunday evening to mix out the inversions/poor air quality over the Columbia Basin and bring a little bit of snow to the higher elevations of the Cascades. Some models hint at a stronger storm on Monday that could bring moderate rain and blustery conditions to the coast, but there is, as always, very little confidence in individual storms more than 5-6 days in advance.
Current Weather:
The dominant feature of the past two weeks – and the reason why we’ve been so unseasonably warm, dry, and sunny – has been a persistent ridge of high pressure in the NE Pacific. This ridge has directed the jet stream north into Alaska, leaving the entire West Coast much drier and warmer-than-average. Meanwhile, a large trough “downstream” (east) of this ridge has brought repeated cold shots to the Central and Eastern US.
I walk to work in the mornings – I’m just glad I work in Portland and not Chicago!
The combination of air temperatures in the single digits and blustery northwest winds has sent wind chills below zero this early this morning. Dress warmly if heading outside early this morning! pic.twitter.com/9imB0FEIVv
— NWS Chicago (@NWSChicago) November 12, 2019
The current satellite/upper-level chart below shows plenty of clouds streaming over the top of this West Coast ridge, but consolidated storm systems have really had a tough time punching through this ridge and making landfall along the coast. A front brought a little bit of precipitation to Washington and Northern OR on Tuesday, but it was pretty anemic by November standards.
Credit: University of Washington
This ridge will strengthen Wednesday and Thursday, giving us mostly sunny skies with temperatures in the mid-upper 50s. The Willamette Valley (including the Portland metro area) could see some fog Wednesday morning, and the Central/South Valley could see another round of fog Thursday morning. The East Wind is expected to ramp up Wednesday afternoon and evening for Portland, and this should preclude fog from forming Thursday morning for the Columbia River Gorge. This will be a weak and short-lived East Wind event; I’d be surprised if Crown Point topped 55 mph, and it should all be over by midday Thursday.
Credit: University of Washington
A moderate front will come through on Friday, bringing a brief shot of rain and high-elevation snow to the Pacific Northwest.
Credit: University of Washington
Saturday currently looks dry as a ridge moves over the Pacific Northwest and directs an atmospheric river into Vancouver Island, but some light rain from this storm could reach us Sunday evening. If I were still living in Seattle, I’d be closely watching this feature for slight southward shifts in future runs, but I think Portland is too far south to see any significant precipitation from the storms this weekend.
Credit: University of Washington
However, models finally show Portland getting a more November-esque storm to begin the following work week. Confidence in individual systems that far out is always extremely low, but you can bet I’ll be watching this baby closely – I’m dying for even a somewhat decent storm to blow through! I’ve purposely omitted a weather model graphic like the ones above because they are unreliable this far out and the solutions have been changing run-to-run, but I’ll provide updates on my Twitter and Facebook pages as this event gets closer and potentially write a blog if I have time.
The tl;dr (too long, didn’t read):
Expect nice weather Wednesday/Thursday, albeit with morning fog in spots and breezy winds near the Columbia Gorge Wednesday evening and early Thursday morning. A moderate front will come through Friday, but nice weather will return for Saturday and much of Sunday as a ridge over our area sends an atmospheric river into Vancouver Island and keeps us dry and mild. Light rain should return Sunday night, and we may finally see a more “typical” November storm on Monday, but confidence is low that far out.
Unfortunately for ski bums, weather geeks, and anybody else who prays for active weather, models bring back this dreaded West Coast ridge by next Tuesday and keep it around through next Friday, so next week looks drier and warmer-than-normal. With the potential exception of that singular storm on Monday, I don’t see any signs of us returning to a traditional, stormy November pattern before next weekend.
Storm season may be late, but it will come – I can promise you that.
Charlie