February 2024 Weather in the PNW

[Phishy Wx]

 

 

[Sunriver Snow Zone]

Super nice day at Bachelor, over a foot of fresh snow!

[SouthHillFrosty]

Flurries in downtown Seattle rn from the wifey.

[RCola]

8 minutes ago, SouthHillFrosty said:

Flurries in downtown Seattle rn from the wifey.

Can confirm, although it's mostly rain. No slushy inch this time, unfortunately, but we at least had flakes last night for a bit. 

[DareDuck]

27 minutes ago, Sunriver Snow Zone said:

Super nice day at Bachelor, over a foot of fresh snow!

Going to Willamette tomorrow. Think it should be a pretty fun morning with 6-10” 

[BLI snowman]

2 hours ago, Cascadia_Wx said:

Makes sense. A Bonneville accumulation cutoff is a pretty far cry from seeing snow here.

Probably was some up at Cape Horn as well I'd guess, but obviously that's with elevation.

[SilverFallsAndrew]

I’m cautiously optimistic for a nice onshore flow regime. I think it will be transitory. 

[MR.SNOWMIZER]

Light snow still falling at home, 33.5 degrees. Totally impressive winter day.

[Deweydog]

1 hour ago, High Desert Mat? said:

Just a quick question for the stat guys on here. During the winter of 2016-2017 was there an SSWE? One or multiple? 

Nope. Although the PV was rather weak. 

[ShawniganLake]

Been snowing all day but it’s melted faster than it’s accumulated.  Back to green grass now.  

[High Desert Mat?]

7 minutes ago, Deweydog said:

Nope. Although the PV was rather weak. 

Thanks. Just was an insanely cold and snowy winter over here and thought maybe there were a few of them. So in hindsight, I guess root for a weak La Niña with a weak PV throughout the winters ahead. 

[SilverFallsAndrew]

I don’t think anyone ever mentioned a SSW on here until 2018.

[Cascadia_Wx]

Just now, SilverFallsAndrew said:

I don’t think anyone ever mentioned a SSW on here until 2018.

They were known of/mentioned here, but mostly relegated to Phil jibberish before that.

[Phil]

 

2 hours ago, MossMan said:

You just need to move back here so you too can enjoy our annual February/March epicness! 

I thought you said spring is your least favorite season? Also it could snow 2-4” here tomorrow night!

Ironically, I enjoy warmth/ridging mid-March to mid-April, as long as there is variability. Also it’s the only time of year we can get warm temps without humidity (autumn still has residual mugginess and is usually very stagnant).

1 hour ago, High Desert Mat? said:

Just a quick question for the stat guys on here. During the winter of 2016-2017 was there an SSWE? One or multiple? 

Nope. The pattern during La Niña/+QBO is usually excellent for cold weather in the PNW regardless of the stratosphere (NPAC high tends to be more amplified in such years).

The cases where SSWEs are more important for PNW cold are usually Niños or neutral years with unfavorable low frequency convective forcing from the eastern IPWP.

[Phishy Wx]

this thing is done.  not going to get the pivot,  looks to be mainly shifting NE and drying out.  fun little system. with the heavy snow burst and wind.  looks like 2-3" total but its blown all over

[Phishy Wx]

18 minutes ago, SilverFallsAndrew said:

I don’t think anyone ever mentioned a SSW on here until 2018.

intelligence levels increased when I started lurking via telepathy

[Phishy Wx]

remember in like I think 2013 ish or so the media went ape shiit about Chicago plunging into the POLAR VORTEX!!!!!!!  I think at that time some more informed or science based media channels and sources explained what was going on.  since then people seem to be more in tune to SSWEs

[Phil]

14 minutes ago, SilverFallsAndrew said:

I don’t think anyone ever mentioned a SSW on here until 2018.

I was talking about them on this forum long before the term “polar vortex” became the popular fad it is today.  You don’t remember because we had no SSWEs from 2014 to 2016. Since 2017 they’ve been very frequent.

The SSW in Jan 2013 played a role in triggering the Pacific climate shift that has led to hotter western summers since then (though I suspect the underlying cause was the longer term extension of the IPWP, which set up tropical forcing in a way that favored said SSW, so perhaps the SSW was simply conduit through which the change occurred, rather than the instigator).

[Phil]

8 minutes ago, Phishy Wx said:

remember in like I think 2013 ish or so the media went ape shiit about Chicago plunging into the POLAR VORTEX!!!!!!!  I think at that time some more informed or science based media channels and sources explained what was going on.  since then people seem to be more in tune to SSWEs

That was 2014, and ironically there was no SSW that winter! Just a very amplified NPAC pattern under -ENSO/+QBO.

The term “polar vortex” is almost always used incorrectly on social media as well. It’s hilarious, as even science media channels/accounts screw it up.

[MossMan]

I miss the old NW terms “Arctic Express” and “Pineapple Express”! I remember the media used those terms for the November and December 1990 events. Atmospheric River sounds to stuffy and official, and Polar Vortex is not my favorite either. 

[MR.SNOWMIZER]

3 minutes ago, MossMan said:

I miss the old NW terms “Arctic Express” and “Pineapple Express”! I remember the media used those terms for the November and December 1990 events. Atmospheric River sounds to stuffy and official, and Polar Vortex is not my favorite either. 

Atmospheric river is used to much, every time it rains for more than 10 hrs its another river!

[MR.SNOWMIZER]

Fresh batch of moisture moving into the area from the coast and there is still light snow falling with a little rain at times. Temp steady at 33.5

[ShawniganLake]

5 minutes ago, MR.SNOWMIZER said:

Atmospheric river is used to much, every time it rains for more than 10 hrs its another river!

Media has fallen in love with that one recently up here. Especially since the historic BC floods a couple years back. Every couple weeks the headlines are sensationalizing the next “atmospheric river”. 

[LowerGarfield]

We had solid flurries all morning and early afternoon but it's over and nothing really stuck.

[Cascadia_Wx]

38 minutes ago, Phil said:

I was talking about them on this forum long before the term “polar vortex” became the popular fad it is today.  You don’t remember because we had no SSWEs from 2014 to 2016. Since 2017 they’ve been very frequent.

The SSW in Jan 2013 played a role in triggering the Pacific climate shift that has led to hotter western summers since then (though I suspect the underlying cause was the longer term extension of the IPWP, which set up tropical forcing in a way that favored said SSW, so perhaps the SSW was simply conduit through which the change occurred, rather than the instigator).

I remember you talking about the January 2013 SSW. And for a time there you were blaming the climate shift associated with it for ushering in our era of hot summers.

[SilverFallsAndrew]

Speaking of climate shift!

[Phishy Wx]

40 minutes ago, MossMan said:

I miss the old NW terms “Arctic Express” and “Pineapple Express”! I remember the media used those terms for the November and December 1990 events. Atmospheric River sounds to stuffy and official, and Polar Vortex is not my favorite either. 

the ol Siberian Express!!

 

All Aboard!!

[Port Angeles Foothiller]

6 minutes ago, SilverFallsAndrew said:

Speaking of climate shift!

Pour one out for Phil

[Willamette Weenie]

7 minutes ago, SilverFallsAndrew said:

Speaking of climate shift!

The Coriolis effect and angular momentum of the prevailing trade winds coupled with the baroclinicity often experienced during an occluded front has the potential to directly impact positive thermal vorticity advection leading to a significant change in the Beaufort scale over the pacific deformation zones during the transition from one extreme to the other... *falls asleep dreaming of two feet of fresh snow on Christmas morning*

 

[the_convergence_zone]

41 minutes ago, ShawniganLake said:

Media has fallen in love with that one recently up here. Especially since the historic BC floods a couple years back. Every couple weeks the headlines are sensationalizing the next “atmospheric river”. 

The research group out of Scripps (CW3E) that studies atmospheric rivers is very good at marketing them. It's just worth remembering that California is funding a big chunk of that research and most of the forecast products are tailored for California. By their California-centric definitions, pretty much every single front has an atmospheric river. So they put out statistics that say that the PNW gets hit by something like 50 atmospheric rivers every winter. The ongoing storm probably was classified as having a weak (category 1) AR making landfall in Oregon last night. 

Outside of their group, there's been some interesting research showing that water vapor doesn't really get transported 1000s of miles within an AR...a huge component of it is actually local moisture convergence. So it's not even really correct to think of them as rivers, they are low level jet streams with high moisture content that are largely forced by frontogenesis. I was once at a hydrology conference where someone remarked that "real rivers are channeled between banks" or something to that effect which of course isn't happening in the atmosphere.

Lots of good work coming out of CW3E and talented people working there, but just keep the above in mind. 

[TacomaWx]

44/34 today with a trace of snow and 0.37” liquid. The chilliest day we’ve had since the deep freeze. 

[Meatyorologist]

8 hours ago, SilverFallsAndrew said:

Did seem like a lot of folks north of PDX thought they would get snow. Which is pretty funny,  but this has to be devastating for many. Total bust. Lesson is: it has to be cold to snow.  

idk i was happy with what i got, a trace around 3am. not too bad.

[High Desert Mat?]

1 hour ago, Phil said:

 

I thought you said spring is your least favorite season? Also it could snow 2-4” here tomorrow night!

Ironically, I enjoy warmth/ridging mid-March to mid-April, as long as there is variability. Also it’s the only time of year we can get warm temps without humidity (autumn still has residual mugginess and is usually very stagnant).

Nope. The pattern during La Niña/+QBO is usually excellent for cold weather in the PNW regardless of the stratosphere (NPAC high tends to be more amplified in such years).

The cases where SSWEs are more important for PNW cold are usually Niños or neutral years with unfavorable low frequency convective forcing from the eastern IPWP.

Ok so since we’re supposedly going back to a La Niña next fall/winter and a decent one at that, what is the QBO predicted to be? Or can those be predicted that far out?

[Eugene-5SW]

31 minutes ago, the_convergence_zone said:

The research group out of Scripps (CW3E) that studies atmospheric rivers is very good at marketing them. It's just worth remembering that California is funding a big chunk of that research and most of the forecast products are tailored for California. By their California-centric definitions, pretty much every single front has an atmospheric river. So they put out statistics that say that the PNW gets hit by something like 50 atmospheric rivers every winter. The ongoing storm probably was classified as having a weak (category 1) AR making landfall in Oregon last night. 

Outside of their group, there's been some interesting research showing that water vapor doesn't really get transported 1000s of miles within an AR...a huge component of it is actually local moisture convergence. So it's not even really correct to think of them as rivers, they are low level jet streams with high moisture content that are largely forced by frontogenesis. I was once at a hydrology conference where someone remarked that "real rivers are channeled between banks" or something to that effect which of course isn't happening in the atmosphere.

Lots of good work coming out of CW3E and talented people working there, but just keep the above in mind. 

Thank you for this excellent clarification.

I recently saw a nature documentary on PBS that took the "atmospheric river" metaphor to absurd lengths, with woozy new-agey narration saying that atmospheric and terrestrial rivers are just the same because they're both life-giving forces, or some such drivel.

Really makes me cringe when they do this. I'm all in favor of bringing science to the masses, but let the science stand on its own without distortion or exaggeration for dramatic purposes.

[ShawniganLake]

1 hour ago, Willamette Weenie said:

The Coriolis effect and angular momentum of the prevailing trade winds coupled with the baroclinicity often experienced during an occluded front has the potential to directly impact positive thermal vorticity advection leading to a significant change in the Beaufort scale over the pacific deformation zones during the transition from one extreme to the other... *falls asleep dreaming of two feet of fresh snow on Christmas morning*

 

That actually happened here in 1937. 26” of snow fell at Shawnigan lake on December 25th. 40” between the 23rd and 25th. Could you imagine 2+ feet of snow falling on Christmas Day.  

[Sunriver Snow Zone]

21 minutes ago, ShawniganLake said:

That actually happened here in 1937. 26” of snow fell at Shawnigan lake on December 25th. 40” between the 23rd and 25th. Could you imagine 2+ feet of snow falling on Christmas Day.  

Something like that is probably the best weather that can exist, maybe this year will be the year. There's nothing like a Christmas snowstorm.

 

If only our Feb 24th-26th 2019 snowstorm could've been December 24th-26th, that storm gave us 34" of snow, and over 2 feet fell on the 25th. Ive experienced quite a few white Christmas's, but never anything close to 2 feet in a day.

[MossMan]

17 minutes ago, Sunriver Snow Zone said:

Something like that is probably the best weather that can exist, maybe this year will be the year. There's nothing like a Christmas snowstorm.

 

If only our Feb 24th-26th 2019 snowstorm could've been December 24th-26th, that storm gave us 34" of snow, and over 2 feet fell on the 25th. Ive experienced quite a few white Christmas's, but never anything close to 2 feet in a day.

If December 1996 would have happened (the big overrunning event) 3 days earlier I would have experienced a 2 foot Christmas! 

[T-Town]

52 minutes ago, ShawniganLake said:

That actually happened here in 1937. 26” of snow fell at Shawnigan lake on December 25th. 40” between the 23rd and 25th. Could you imagine 2+ feet of snow falling on Christmas Day.  

We always host Christmas at our place and have lots of family over to celebrate. Two feet of snow would mean people couldn’t come over, which would be disappointing. Or it might mean they couldn’t leave, which would be VERY disappointing. 

[Ken in Wood Village]

I can say this, my weather station never reached 40 degrees today. We reached 39.9 degrees we are sitting at 36.9 degrees now. It's been a cold raw day here with a little east wind blowing which makes it feel a little colder  

[MR.SNOWMIZER]

2 hours ago, TacomaWx said:

44/34 today with a trace of snow and 0.37” liquid. The chilliest day we’ve had since the deep freeze. 

34/32, got some cold air trapped real good over here. still snow on trees in spots