The latest satellite image shows the rapid development of the offshore storm.
The visible satellite image around 9 AM was stunning, with low-level clouds swirling around the low center (the orange arrow points to the low center).
Stunning.
Here is the blow-up of the clouds around the low center. The circulation is obvious.
Strong, rapidly developing storms not only have rising motion that produces clouds, but intense sinking motion that produces a "slot" dry air coming in from the southeast.
We can view the "dry slot" using satellite images that reveal water vapor content in the upper and middle troposphere. Such an image is shown below, with blue indicating very dry air. This is a strong storm... no doubt about it.
The latest National Weather Service surface map (and I do have some issues with the quality of their analyses) shows the storm at 7 AM, with an analyzed lowest surface pressure of 974 hPa. The storm is rapidly deepening today, so the pressure will fall considerably more.
As I mentioned in my previous blogs, although strong coastal winds are an issue, my biggest concern is for strong winds east of Puget Sound tonight.
The models are still going for threatening winds....with the clear threat of substantial tree damage and power outages.
The latest European Center forecast predicts winds exceeding 70 mph on the east side of Puget Sound, particularly towards the western Cascade foothills. These are all easterly and southeasterly winds....not the usual direction of strong local winds.
The maximum wind over Seattle based on dozens of predictions is predicted to hit 45-60 mph...from the east (see below).
Bottom line: strong winds from the east, gusting to 40-70 mph, will occur east of Puget Sound and will be stronger towards the Cascades. Expect substantial vegetation damage and many power outages. Driving down streets with lots of trees might not be a good idea after 6-7 PM if you living in the vulnerable areas noted above.
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Some satellites can measure low-level winds by measuring wave action...called scatterometers. Here are the surface winds from a scatterometer around the storm around 12:30 PM PST. The intense circulation around the low is obvious.
Cliff, so the winds will be blowing from the east to the west??
ReplyDeleteAir (winds) flow from areas
Deleteof high pressure to low pressure (in an effort to equalize pressure). The LOW is to our West - hence the winds out of the East (flowing towards the low)
Hi Cliff. Thanks for providing so much information on this storm. I live near Gold Bar on highway 2 where we can get really strong gap winds when nobody else gets much impact. The models don't look much worse through the gaps than what's expected over the entire region. Should I be expecting an even worse impact here, or is this a different beast than the usual gap winds scenario?
ReplyDeleteTo answer my own question, it was similar to a fairly typical strong gap wind event out here in my neighborhood. Strong winds for hours. Lots of 40+ mph gusts with a max of 54, I believe.
DeleteThank you for the updates! Your vast knowledge, experience, and input is certainly appreciated in events like these.
ReplyDeleteShould residents of King and Snohomish counties need to worry?
ReplyDeleteThat’s a large region you’re asking about! Did you read all that he wrote? Prepare for a power outage and prepare your yard/porch/etc for severe winds. Better safe than sorry.
DeleteBlowing maybe 5mph in sultan... over stated as usual
ReplyDeleteAnd one resident from Sultan speaking for the entire state of WA. Unneeded as usual. Multiple trees down in our area. No power. No water. Multiple neighbors are dealing with trees on houses.
DeleteToo soon Junior.
DeleteShe's a beast
ReplyDeleteAny from the ground images you've seen from inside or close proximity to a Pacific cyclone like this?
ReplyDeleteAm I wrong or is the eastern pacific isobar map now reading 955, which is 5 lower than Columbus Day Storm? Yikes!
ReplyDeleteNaw....That CD windstorm was measured lowest, at 950....the thing is, that titanic event (which I lived through at age 15) was exceptionally devastating, because it decided to move much closer to the coastline than this storm will do. Therefore, Oregon suffered winds in excess of 145mph at times, and Puget Sound became the perfect "wind tunnel" from South to North, experiencing the somewhat weakening wind blasts that still exceeded 100mph in a few locations. The eye of the CD monster storm finally veered into Vancouver BC area, still leaving a 90mph gust in the Bellingham area. before degenerating slowly into a rainstorm. Living in the Greenlake area of Seattle, I will never forget that storm--it was our only "real" Category 2 Hurricane that Western Washington has ever hosted! Tonight's blast was not positioned to do ultimate damage, compared to the 1962 storm.
DeleteOur barometer must ticked by 996, which isn’t of itself low, it that pressure is down 12 hPa from 8 1/2 hours ago, a decent fall. Power is out here in NE Seattle and surrounding neighborhoods.
ReplyDeleteWe live on Camano Island. I’ve never seen anything like this. We’ve lost power, trees are down, looks like it’s going to be a very long night. Stay safe. You warned us Cliff. Thank you!
ReplyDeleteYou were right as usual. Already had a tree take out a big section of my fence. I can hear trees crashing every few minutes. We are on the south slope of Tiger Mountain.
ReplyDeleteOn 12/27/22 the low press also hit 970. That combined with a king tide, flooded thousands of our homes and cabins in the Puget Sound with over 2+ feet of higher than normal tide. Back then you said it was a “100-year event”… While local tides aren’t “king” they are very high. Are we in for another disastrous flooding event?
ReplyDeleteWell, that was interesting. I was doing a safety check of the neighborhood when I heard, among the wind gusts, what I knew immediately was a much stronger localized burst of wind. Even without power and lights I could see an intense cyclonic shaped swirl of leaves moving across the neighborhood from ENE toward WSW very loudly, bending large trees and violently shaking bushes. It knocked over several neighbors garbage bins, even with contents and then moved past me and was gone. I liken it to a notable eddy in a river near already fast moving water in rapids. Live and learn.
ReplyDeleteI’m in Sammamish. We have a tree on our roof that punched through into our living room. Broke a window and took part of the deck off. Not sure what else got damaged because it’s not safe to go out there to look
ReplyDeleteIt’s been and continues to be a doozy of a night her in Mirrormont. I am currently bunking with my son on a basement couch in sleeping beds with no electricity and a massive tree through my upper floor. I dread seeing the extent of the damage to my home in the morning.
ReplyDeleteIn Olympia last night the wind never got over 14mph and for hours was between 0 & 5 mph. It was like sitting in a hurricane eye.
ReplyDeleteI live in the Tacoma area and it was a literal bubble of calm all night. Barely even a breeze. Heard folks in Olympia were experiencing the same. Amazing when less than ten miles away it was 50 mph gusts.
ReplyDeleteI came here to say the same thing. I'm curious as to why Tacoma was spared.
DeleteToo far south and west for the downslope winds
DeleteThe Tacoma News Tribune had an article today (11/20) that credited Mt. Rainer with shielding Tacoma from the winds. This is the first time I can remember with any windstorm that the volcano (in theory) protected the Tacoma area.
DeleteThis was wild. We live in Orting. If I were to have driven 15 min up the hill, everything was going crazing. Not even my flag wiggling out front. I watched Pacific Northwest storm watchers on YouTube catch two separate 70 mph gusts in Enumclaw.
ReplyDeleteI’m anxious to see if the next event follows the same path.
On SW whidbey we had very little impact from wind though elsewhere on the island there are lots of power outages. If you want to see impact look at the Puget Sound Energy webpage and from there to outage map! Wow
ReplyDeleteNothing happened last night except lots of rain and breezy. The storm looked amazing on satellite!! We're just south of Port Townsend.
ReplyDeleteWhat turned out to be the lowest millibar reading for the storm?
ReplyDelete942 hPa
DeleteProfessor Mass
ReplyDeleteOur barometer bottomed at 994 hPa. Not remarkable but the quick journey there, from 1009 in the morning, was. Still, if the next storm develops as it may it could be even stronger if it gets into 980s, and especially if into the 970s.
Professor Mass, what are you thinking about this?
“National Weather Service”
“Organized front associated with a developing surface low in the base of the upper level low turning towards Western Washington Thursday night. 999 mb low at 00z Friday will deepen to around 985mb while moving north northeast Thursday night. By early Friday morning the low will be west of the mouth of the Columbia River
near 129W. Rain out ahead of the front spreading over the southern portion of the area late. Lows in the lower to mid 40s.
“Front moving through Western Washington Friday. Surface low will continue to strengthen bottoming out near 975 mb. Winds increasing
Friday morning with the potential for wind advisories along the coast and over the Northwest Interior. If the low deepens a little
more than the models indicate or the track is a little further east could need a high wind warning for the coast Friday.”