Seattle Weather Blog @KSeattleWeather

First Friday Halloween in 11 years.

First rainy Halloween in … 1 year.

: 3:20 PM · Oct 31, 2025

#WAwx #ORwx #BCwx #PNWwx #PNW #KSEA #NWS #WX #Weather

Whoa

Stevens Pass US Hwy 2 Washington

Pass report:

Elevation: 4061 ft / 1238 m

Air Temp.: Not available

Travel eastbound: Traction Tires Advised, Oversize Vehicles Prohibited.

Travel westbound: Traction Tires Advised, Oversize Vehicles Prohibited.

Conditions: Compact snow and ice

Weather: Snowing

Last updated: Saturday, October 25, 2025 11:53 AM

Here: https://wsdot.com/travel/real-time/mountainpasses/stevens

#WAwx #ORwx #BCwx #PNWwx #PNW #KSEA #NWS #WX #Weather #Snow

The atmospheric river has arrived 👀

#WaWx #OrWx #BCwx #PNW #seattle

It’s gonna be heckin’ wimdy.

“Wind gusts up to 90 km/h expected for the Cariboo”

#BCWx #BCStorm
https://cfjctoday.com/2025/10/23/wind-gusts-up-to-90-km-h-expected-for-the-cariboo/

huh...

Both Snoqualmie Pass I-90 and Stevens Pass US Hwy 2, Washington, are reporting snow

Snoqualmie Pass at 3022 ft, Stevens Pass at 4061 ft in the Cascade Mountains

Can't see anything sticking, and no temperatures reported because we're not in the "reporting" season yet...

#WAwx #ORwx #BCwx #PNWwx #PNW #KSEA #NWS #WX #Weather #Snow

If you’re driving the #Coquihalla today, be careful—and make sure you’ve got good winter-rated tires!

#BCStorm #BCWx
https://cfjctoday.com/2025/10/11/special-weather-statement-expanded-to-include-coquihalla-between-hope-and-merritt/

An illegal dam on Fadear Creek is apparently looking to be about to fail #lang_en #BCStorm #BCwx #CAPol

Series of atmospheric rivers to bring heavy rain to Washington, Oregon, and northern California through early October

A series of atmospheric rivers (AR) is forecast to hit the U.S. West Coast from late September through early October, beginning with a strong AR that made landfall over British Columbia on September 26, 2025. Forecasts show moderate AR conditions in Washington, Oregon, and northern California on September 28, followed by a stronger system making landfall on September 30 and potentially continuing into October 7. #weather #AR #WAwx #ORwx #CAwx #BCwx
https://watchers.news/2025/09/27/series-atmospheric-rivers-bring-heavy-rain-washington-oregon-northern-california-early-october/

🥇#Vancouver hasn't recorded a temperature below 9°C in 126 days, which is the longest run on record. #YvrWx #YVR #BCWx

P.S. Important and much appreciated input from Ed Wiebe M.Sc. at UVic Earth & Ocean Science

https://mstdn.ca/@edwiebe/115265785432541292

#PortAlberni #BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

8/end The question is.. what will those totals look like?

Could we see a 150mm-200mm in-a-day rainfall event? 1000mm over a few days? More?

Or perhaps even if it happened just right in January or February, could we see a massive snowfall event reminiscent of last century?

We won't know until it happens, but we can see the signs that our time is coming.

#PortAlberni #BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

7/n We have seen a number of times in the past 10 years, most dramatically in 2021, where small and large Atmospheric River events have seemed to "go around" Port Alberni... often impacting the Lake Cowichan area most.

Our strongest events have always been when winds lined up best with the opening of the Alberni Inlet, roughly South to Southeast. So we will have our moment.

#PortAlberni #BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

6/n What I don't believe we have yet experienced in Port Alberni — as a matter of luck — is the full force of a extra-water-vapor-laden Atmospheric River event.

Whereas before #PortAlberni could rely on our geography to 'squeeze' moisture out of almost any frontal system as it rammed into the inland Vancouver Island mountain ridges, today with generally warmer/drier air, that's not enough.

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

5/n We have also noticed far fewer foggy days in Port Alberni in Spring and Fall and this year there were almost none in Summer, when in previous decades we could expect to see fog on more than few days.

These are all indications (anecdotal) that would go along with the notion that as the temperature is rising, the air is drying, making precipitation in general much less frequent.

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

4/n Thinking about it... Port Alberni in the summer is a very dry place. As the sun rises higher in the sky in Spring, there is more opportunity to dry out the air and land... combine that with rising average temperatures, especially on the low end (at night/early morning) and that means the air is drier making it less likely to rain when we would normally receive rain from even small frontal systems.

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

3/n “Because onset of rainfall depends on relative humidity, rain events on land become less frequent. But when rain events are triggered by weather systems, they become larger, more intense and more likely to cause flooding, as is also observed to be happening”

We have most definitely seen this change in behaviour on Vancouver Island!

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

2/n part1 "Because land temperatures are rising faster than ocean temperatures [figure attached] as air moves from the ocean to the land as part of the hydrological cycle (ocean evaporation, wind moisture transport to land, rain on land, runoff and flow of water in rivers back to the ocean), the relative humidity of air drops. This is now clearly observed on land even as the total moisture has increased.”

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

1/n Really interesting Post on The Climate Brink from Dr. Kevin Trenberth.

TIL: "Weather systems reach out and gather in moisture typically from over a distance about four times (3 to 5) the diameter of the precipitating area.”

Handy guide!

But there is a paragraph in particular that intrigues me and I want to parse it out in the next couple replies/toots in this thread.

#BCWx #Weather #BCStorm #AtmosphericRiver #ClimateChange #ClimateExtremes #Flooding

https://www.theclimatebrink.com/p/the-undeniable-science-of-extreme?utm_source=post-email-title&publication_id=1593097&post_id=174213380&utm_campaign=email-post-title&isFreemail=true&r=3995q&triedRedirect=true&utm_medium=email

🥈Streak over. After 15 consecutive September days with minimum temperature ≥12°C in #Vancouver, the minimum temperature was only 10.5°C yesterday. We made it to 2nd place, only 2 days behind the record. #YvrWx #YVR #BCWx

🥈#Victoria International Airport hasn't recorded a temperature below 9°C in 92 days, which is the 2nd longest on record. #YyjWx #YYJ #BCWx