Fortunately for everyone, the wind storm didn‘t happen. The European model had far and away the best forecasts for the event, although there were enough stronger members in the ensemble spread to trigger warnings/advisories.

I feel bad for the NAM model, it just wants one last time to shine before NOAA cuts the cord in 2026. Fortunately it is 10-15+ years outdated and the modeled 70+ mph winds are NOT going to happen in Seattle. Doesn't mean there won't be a significant storm, but not apocalypse level!

Will there be a Christmas Eve windstorm? It would be nice to have an answer, but unfortunately the best meteorologists can do is say "maybe, maybe not". I'd say it probably leans about 75/25 in favor of a minor event, so let's hope that ends up being the case.

Potential X-mas eve windstorm update -- The European model has a weaker and more inland low resulting in mostly non-damaging winds. The GFS ensembles are stronger and farther west, resulting in an event that could be damaging for many areas. Probably will come down to a nowcast 🤷

PNW wind storms exist to frustrate forecasters. After a bunch of news articles ran today, the threat greatly diminished in the models. Wednesday just looks to be a normal day with light rain and a gentle breeze. Unless the models flip again 😅

It's raining again...that makes it 18/22 days with measurable rain this December in Seattle, 20/22 if you include 2 days with a trace.

They're trying to squeak one more Harrell Administration priority through before the end of the year: allowing huge-ass corporate signs on skyscrapers in Downtown Seattle. services.seattle.gov/Portal/Cap/C...

A Christmas Eve windstorm is appearing increasingly likely with a compact 980 hPa low + trailing sting jet expected to take a troublesome S to N track. Willamette Valley, coast, PDX, SEA metros all potentially impacted. Lots of model uncertainty…follow forecasts closely. Could be a bad one.

Watching a possible snow event for the WA lowlands on Christmas Eve. Currently looks like a "dusting on the higher hills" type event for Seattle. Areas north and at higher elevations have a better chance at seeing accumulating snow, but it's still too early to tell...

Sea-Tac is now over 7 inches of rain for December. Average Dec total is 5.90 in. The high water mark for Dec is 11.85" from 1979. Second is Dec 2015, 11.21". Models suggest that we'll get to the 12-13 inch range by the end of the month, which would be #3 all time for any month.

"What if it was all snow?" It was at one spot in Washington -- Harts Pass, the highest elevation SNOTEL site in the Washington Cascades. Snowpack is now 173% of normal for the date. Last winter it took until March 14 to reach this level of snowpack.

What’s the likelihood this actually happens? Killing the mothership would be the knockout blow for weather and climate research in this country.

Efforts by the USACE and facilitated by accurate NWS forecasts appear to have significantly reduced impacts from record flooding on the Skagit River in WA last week. A look at how that worked and why we have to protect the foundations of our fed science/water agencies. tinyurl.com/bdebat4m

This is incredible -- if the claims are true that the Skagit crest height was reduced by 4-5 ft (consistent with some forecasts), this emergency measure may have saved hundreds of millions in damage to Mt. Vernon and other towns along the Skagit river.

A flash flood warning has been issued for a levee failure on the Green River near Tukwila Evacuation info: This is for residents and businesses east of the Green River in the Orillia area in Tukwila, Renton and Kent. Due to breach in the Desimone Levee, this area is under a GO NOW evacuation notice

SEW corrects Flash Flood Warning [flash flood: observed, flash flood damage threat: considerable, levee failure: occurring] for King [WA] till Dec 15, 9:00 PM PST Link

Sea-Tac is now over 5.25" of rainfall for December. Normal for the entire month is 5.75". Model forecasts show about 2 additional inches falling this week.

I spent way too much time on a Saturday analyzing snowfall trends in Washington, but it does appear that the start to snow season in the WA Cascades has trended later in recent decades. Check out my post to learn more...

The catastrophic flooding has been rough to handle, so here's some good news. One more warm atmos river on Monday, then the Cascades are going to get pummeled with snow when cold air finally moves in next Wednesday. Snoqualmie Pass could see 4 feet of snow by Christmas. Skiing will be great.

Another record stage reached on a western Washington river, this time the Cedar River at Renton. Records go back to at least 1940. #wawx

A brief summary as the atmospheric river finally tapers off, with the worst flooding along the Skagit river still to come.

Here's a sampling of some rainfall totals since Monday morning if you were wondering why rivers are experiencing historic flooding in the WA Cascades. Normally one would expect at least some of this to fall as snow in the high terrain, but it was 100% rain in this area.

Morning update: it rained all night and the Snohomish River is now above its modern record and still rising. For now the Snoqualmie River remains slightly below record level, but still in major flood stage.

This storm is just crazy to watch on radar. Nothing but a little drizzle in the lowlands but as soon as the flow hits the foothills it gets the lift needed to produce a deluge. 55 degrees with 95% humidity In Seattle.

Lake Quinault is now higher than the peak in 2015 (14.7 ft) that produced the photo of Josh Wurman kayaking around the DOW during the OLYMPEX campaign. Those were some crazy strong storms, can’t believe this topped it.

While rain has been the main story, Washington Pass in the North Cascades has somehow managed to stay below 32 F all week. As a result, there is at least one site in the PNW sitting well above normal with snowpack this year while everyone else drowns in rain.

Main Topic: November and Fall 2025 Record Scoreboard and Climatological Review On The Extreme Temperature Diary MON 12/08/2025 At: guyonclimate.com + #climate #weather and record temp reports @michaelemann.bsky.social @katharinehayhoe.com @capitalweather.bsky.social @brianmchugh.bsky.social

These subtropical air masses that reach the PNW keep getting warmer and wetter as the climate warms as a whole. Yakima, WA has reached 70 degrees today, the only other 70+ in Dec was 72 on 12/1/2021. The atmospheric water vapor content is near record highs for Dec, increasing rainfall amounts.

The persistence of this atmospheric river is apparent from the morning radar. Flow straight from the west impinging on the Cascades. ~0.5 inch/hour rain rates in the Cascades will continue past midnight tonight — over 24 hours in total in the worst hit spots.

This is quite the forecast. Would be really bad if it verifies.

Round 2 precipitation forecast — this afternoon through Wednesday night. That blob of purple in the central Cascsdes is of particular concern where 12”+ of rain could fall if this model is right. Rivers are already high before this starts!!!

Models are showing the second atmospheric river on Wednesday stalling over the central Cascades. Currently the Snohomish River looks to get the worst of it, with record flooding possible. This could be a a serious disaster.

The rain is gradually winning the battle against the rain shadow. Going to be a wet evening.

Update on the ongoing two-part atmospheric river event: theconvergencezone.com/2025/12/08/t...

A category 5-ish atmospheric river (based on intensity & duration of moisture delivery over the PNW) is setting up over the entire width of the North Pacific this week. Forecasted to be ~3x longer than avg ARs. 1/2 www.washingtonpost.com/weather/2025...

A new entry in the PNW weather model hall of fame. Nearly a quarter of the annual average rainfall for many areas in just two weeks. Still unsure if the deluge will reload for a second week, but if it does then many December rainfall records will fall. Wet gets wetter as the climate warms…

You can always count on Mt Rainier to provide some maxed out colormaps during a good storm cycle.

Strong rainshadowing is expected this week, especially in north King and Snohomish counties. This is for the next 48 hours — 7x more rain at Sea-Tac compared with Paine Field.

This is U N B E L I E V A B L E. #Kilauea

I'm back from a long blogging hiatus with a post on the series of atmospheric rivers expected to cause flooding in the PNW next week: theconvergencezone.com/2025/12/05/f...

Looks like a major Atmospheric River (cat 4-5) will impact the PNW early next week. With minimal snowpack this will likely produce serious runoff and cause river flooding. Stay tuned…

I wonder where every single storm coming from the Pacific is going to make landfall over the next 2 weeks...

🚨 Monday ice update - #Arctic sea ice extent is currently the lowest on record (JAXA data) • about 1,110,000 km² below the 2010s mean • about 1,600,000 km² below the 2000s mean • about 2,310,000 km² below the 1990s mean • about 2,810,000 km² below the 1980s mean More: zacklabe.com/arctic-sea-i...

12/1 PNW snowpack update -- not good. Forecast: mild and wet for the first 10 days of December, so these anomalies will get worse in the short term. The silver lining: it only takes one good storm cycle to get back to normal in the early season.

Seattle still hasn't even been close to a frost this fall, but that may change in about 8 days. Arctic air is expected in the intermountain West, with some intrusion possible into the PNW. About 2/3 of EPS members show at least some cold getting to Seattle, but a high impact event seems unlikely.

Congrats to Miami, FL, for tying their record low for the date. This is their first record low since Feb 20, 2015. Since the previous record low, they have set or tied a daily high temp record 182 times. 2015: 14 2016: 11 2017: 13 2018: 6 2019: 27 2020: 24 2021: 9 2022: 21 2023: 36 2024: 14 2025: 7

I know I’m missing one of the greatest baseball games of all time but at least the Decemberists with the Seattle Symphony is very, very good.

Storm rainfall totals for this atmospheric river have eclipsed an inch from Seattle southward. As usual the mountains are quite effective at ringing out additional moisture from these moist vapor streams. It will be a bit windy this morning, peaking around 10-11 AM around Seattle.

You really couldn’t time this any worse for trick or treating if you tried…

Friendly reminder to tell your kids that M&M packaging is not waterproof.