January Weather In The PNW 2024 (Part III) - The Warming Shot

[snow_wizard]

Another cold February would be incredibly ridiculous after our recent run, but it could easily happen the way things look right now.  As it is the 10 year average for Feb is currently the lowest it's been in decades in this area.

[snow_wizard]

Just now, Phishy Wx said:

probably because its clown range GFS

The pattern is interesting well before that though.  It just takes time for the excitement to build.

[Phishy Wx]

Just now, snow_wizard said:

The pattern is interesting well before that though.  It just takes time for the excitement to build.

hit me up if its still around a week from now

[snow_wizard]

5 minutes ago, BLI snowman said:

Lost in the shuffle somewhat is how wet it's been across NW OR and SW WA. PDX's rainfall today puts them over 7.40" on the month, with a ton more on the way. Looking like a double digit month there. The only other 10"+ Januaries at PDX are 1950, 1953, 1956, 1970, and 2006.

Only about 6" up here so far.  Still decently wet though.

[Weiner Warrior]

It'll trend North

[snow_wizard]

The chill is more sustained on this GEFS run as well.  Good trends right now.

[Slushy Inch]

I’m hyped for the new cold chance! Cascadia, Phil, I had a hunch!

[LowerGarfield]

4 hours ago, Phishy Wx said:

This, often the warmest.  its offshore wind season.  Dry and Hot.  high fire risk.

Yup, and as a result you'd have a few days pushing above 85-90 in my coastal foothills region of the Oakland/Berkeley area. Now it's more like 90-100F and a/c is needed when it previously wasn't.

[snow_wizard]

1 minute ago, Weiner Warrior said:

It'll trend North

The models have done well zeroing in on cold in recent years.  They still suck big time for snow of course.

[snow_wizard]

GEFS clearly shows the cold pool in AK sliding down into BC during week two.  That could be a big deal.

[snow_wizard]

Very weird setup, but the models have been consistent on it.  This run is the coldest yet on the GEFS though.

[Doinko]

13 minutes ago, BLI snowman said:

Lost in the shuffle somewhat is how wet it's been across NW OR and SW WA. PDX's rainfall today puts them over 7.40" on the month, with a ton more on the way. Looking like a double digit month there. The only other 10"+ Januaries at PDX are 1950, 1953, 1956, 1970, and 2006.

I've been curious, what was the specific progression like that month to have that much precip/cold? From what I can tell, it looks like there was a small airmass around New Year's with some snow, then a big blast with signficant snow around the 13th, and then another major airmass at the end of the month after a brief warmup? I was wondering about the individual airmasses that affected the region that month mostly. 

[Phishy Wx]

9 minutes ago, LowerGarfield said:

Yup, and as a result you'd have a few days pushing above 85-90 in my coastal foothills region of the Oakland/Berkeley area. Now it's more like 90-100F and a/c is needed when it previously wasn't.

yep we were up in the Santa Cruz Mtns at about 1000' above the fog belt near Felton.  several days in Sept and sometimes in October in the triple digits pretty much every year with no AC.  we'd go down to the wharf in santa cruz to cool off, usually about 10 degrees cooler in those offshore days

[SilverFallsAndrew]

22 minutes ago, BLI snowman said:

Lost in the shuffle somewhat is how wet it's been across NW OR and SW WA. PDX's rainfall today puts them over 7.40" on the month, with a ton more on the way. Looking like a double digit month there. The only other 10"+ Januaries at PDX are 1950, 1953, 1956, 1970, and 2006.

I believe SLE surpassed 8” today. 

[Slushy Inch]

6 minutes ago, snow_wizard said:

Very weird setup, but the models have been consistent on it.  This run is the coldest yet on the GEFS though.

May be a group of members dropping trough into California or just the fact that it seems like the troughing is broad.

[Rubus Leucodermis]

32 minutes ago, Phishy Wx said:

probably because its clown range GFS

Also we already had an arctic blast this winter, so most weenies are not jonesing so hard for one anymore.

[Slushy Inch]

4 minutes ago, Rubus Leucodermis said:

Also we already had an arctic blast this winter, so most weenies are not jonesing so hard for one anymore.

I got no real snow accumulation! I’m jonesing more than ever. Walked 4 miles to see 1/8 an inch, I’m not counting that!

[SnowWillarrive]

57 minutes ago, Sunriver Snow Zone said:

I'm surprised people on this forum aren't going nuts right now. If this run had happened in December there'd be 10 comments a minute, but yall are just really burnt out aren't ya? Glad to see the end of the models are getting fun again!

Looks nice but we already know it will be confined to parts of Hood Canal and MossMans vortex. 

[Rubus Leucodermis]

7 minutes ago, Slushy Inch said:

I got no real snow accumulation! I’m jonesing more than ever. Walked 4 miles to see 1/8 an inch, I’m not counting that!

I am frankly a little surprised that Seattle weenies aren’t jonesing for snow and model riding, but the lack of excitement over the latest clown range GFS trends is what it is. Maybe everyone is just tired of model riding and waiting for it to get less clown rangey.

[Rubus Leucodermis]

8 minutes ago, SnowWillarrive said:

Looks nice but we already know it will be confined to parts of Hood Canal and MossMans vortex. 

I would post about how it will trend north, but I recently just cast that spell and scored a foot as a result. Don’t want to get too greedy.

[Slushy Inch]

2 minutes ago, Rubus Leucodermis said:

I am frankly a little surprised that Seattle weenies aren’t jonesing for snow and model riding, but the lack of excitement over the latest clown range GFS trends is what it is. Maybe everyone is just tired of model riding and waiting for it to get less clown rangey.

Well I am. Could get pretty chilly within 10 days.

[MossMan]

7 minutes ago, Slushy Inch said:

Well I am. Could get pretty chilly within 10 days.

Me too…I want WAY MORE!! 

[snow_wizard]

44 minutes ago, Doinko said:

I've been curious, what was the specific progression like that month to have that much precip/cold? From what I can tell, it looks like there was a small airmass around New Year's with some snow, then a big blast with signficant snow around the 13th, and then another major airmass at the end of the month after a brief warmup? I was wondering about the individual airmasses that affected the region that month mostly. 

The thing about Jan 1950 is it was almost completely -PNA driven.  The lowest monthly PNA average of the 20th century.  The N to S temperature gradient was very strong which allowed frequent undercutting systems to spin /push moisture up over the area.  The shallow southward penetration of cold allowed the systems to move inland underneath us instead of them getting shunted way down to CA.  Quite the perfect little setup. For both PDX and SEA to do well.

We had major intrusions of cold on New Years, around the 13th, and then late month.  The warmup before the last Arctic blast set the stage for a major winter storm that produced very heavy snow, ice, and sleet.  For some places the month end storm produced more snow than the blizzard on the 13th.  Palmer which is very near here had 40 inches of snow with that one and had over 60 inches on the ground.  That was caused by marine air interacting with Arctic air seeping in from the passes in East King County.  Tim's area probably had similar. 

[BLI snowman]

46 minutes ago, Doinko said:

I've been curious, what was the specific progression like that month to have that much precip/cold? From what I can tell, it looks like there was a small airmass around New Year's with some snow, then a big blast with signficant snow around the 13th, and then another major airmass at the end of the month after a brief warmup? I was wondering about the individual airmasses that affected the region that month mostly. 

It was probably the most anomalous PNA blocking pattern in modern history across North America.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.mon.pna.wg.jan1950-current.ascii.table

The modified value of -4.39 represents the most extreme value on record, though December 2021 recently gave it a run for its money.

The progression actually started in mid December with a Fraser River blast that hit northern WA around the 18th. Following that, the pattern reset and reset with each successive airmass digging a little more ferociously than the last while a significant amount of jet support existed under the base of the block .

The blast around the 2nd-4th was significant regionally, followed by days of cold onshore flow and occasional wet snow in the lowlands. Then the block reset in full and delivered a massive airmass into the region.

The Friday the 13th blizzard probably rivaled many of the more intense Nor'easters on record. Highly recommend checking out some of the old obs from that day, the wind speeds and temperatures were insane. A few examples:

BLI

https://www.wunderground.com/history/daily/us/or/portland/KBLI/date/1950-1-13

SEA

https://www.wunderground.com/history/daily/us/or/portland/ksea/date/1950-1-13

PDX

https://www.wunderground.com/history/daily/us/or/portland/kpdx/date/1950-1-13

MFR

https://www.wunderground.com/history/daily/us/or/portland/kmfr/date/1950-1-13

The low passed right over PDX around 5pm, and it wound up being one of the worst southerly windstorms on record for the Rogue Valley. And the worst noreaster on record for Whatcom County. Gusts there approached 80mph with temps in the low single digits.

That was followed by a sharp undercut around the 18th which led to a significant ice storm that produced 2-3" of freezing rain for most of NW OR and SW WA. A few mild days followed regionally before another massive airmass dropped straight down out of BC around the 23rd.

The jet stream yo-yoed with a battle zone setting up for a few more days before a very broad and deep trough settled in and produced a massive eastside cold pool at the end of the month which was boosted by the big snowpack. That cold pool helped produce a 15/-10 day locally on the 31st. Low level airmass held on for a few more days into February before the block shifted east for good.

Edited January 25 by BLI snowman

[snow_wizard]

4 minutes ago, BLI snowman said:

It was probably the most anomalous PNA blocking pattern in modern history across North America.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.mon.pna.wg.jan1950-current.ascii.table

The modified value of -4.39 represents the most extreme value on record, though December 2021 recently gave it a run for its money.

The progression actually started in mid December with a Fraser River blast that hit northern WA around the 18th. Following that, the pattern reset and reset with each successive airmass digging a little more ferociously than the last while a significant amount of jet support existed under the base of the block .

The blast around the 2nd-4th was significant regionally, followed by days of cold onshore flow and occasional wet snow in the lowlands. Then the block reset in full and delivered a massive airmass into the region.

The Friday the 13th blizzard probably rivaled many of the more intense Nor'easters on record. Highly recommend checking out some of the old obs from that day, the wind speeds and temperatures were insane. A few examples:

BLI

https://www.wunderground.com/history/daily/us/or/portland/KBLI/date/1950-1-13

SEA

https://www.wunderground.com/history/daily/us/or/portland/ksea/date/1950-1-13

PDX

https://www.wunderground.com/history/daily/us/or/portland/kpdx/date/1950-1-13

MFR

https://www.wunderground.com/history/daily/us/or/portland/kmfr/date/1950-1-13

The low passed right over PDX around 5pm, and it wound up being one of the worst southerly windstorms on record for the Rogue Valley. And the worst noreaster on record for Whatcom County. Gusts there approached 80mph wind temps in the low single digits.

That was followed by a sharp undercut around the 18th which led to a significant ice storm that produced 2-3" of freezing rain for most of NW OR and SW WA. A few mild days followed regionally before another massive airmass dropped straight down out of BC around the 23rd.

The jet stream yo-yoed with a battle zone setting up for a few more days before a very broad and deep trough settled in and produced a massive eastside cold pool at the end of the month which was boosted by the big snowpack. That cold pool helped produce a 15/-10 day locally on the 31st. Low level airmass held on for a few more days into February before the block shifted east for good.

Great write up and insanely gorgeous map!

[SilverFallsAndrew]

It really annoys me that Silver Falls has no data from January 1950. They did have a 41” snow depth on February 1st though, so I know it was good. I believe locally January 1949 was actually slightly colder, at Silver Falls it was the coldest month on record and I believe its #2 at SLE behind January 1930 (Silver Falls data only goes back to 1938.). Off the top of my head 1950 is the 3rd coldest January on record at SLE. 

Edited January 25 by SilverFallsAndrew

[SilverFallsAndrew]

Given the late month torch that will bump us up near the 30-year average for January we have a chance for this year to be the 6th out of the past 7 years to have a colder February than January. Still think it’s a long shot, but who knows if we get a sustained chilly pattern with a nice cold shot!

[snow_wizard]

I also read somewhere that January 1950 was considered to be the biggest atmospheric anomaly anywhere on the planet in the 20th century.

[snow_wizard]

4 minutes ago, SilverFallsAndrew said:

It really annoys me that Silver Falls has no data from January 1950. They did have a 41” snow depth on February 1st though, so I know it was good. I believe locally January 1949 was actually slightly colder, at Silver Falls it was the coldest month on record and I believe its #2 at SLE behind January 1930 (Silver Falls data only goes back to 1938.). Off the top of my head 1950 is the 3rd coldest January on record at SLE. 

That sound right.  As I mentioned 1950 had a really big gradient.  In 1949 the cold dug much further south.  At SEA 1950 was a lot colder than 1949.

[SilverFallsAndrew]

1 minute ago, snow_wizard said:

I also read somewhere that January 1950 was considered to be the biggest atmospheric anomaly anywhere on the planet in the 20th century.

Hopefully 70 years from now my kids are telling their grandkids they lived through the biggest atmospheric anomaly of the 21st Century. The 2021 Heat Dome. Then the grandkids will ask why we don’t get heatwaves like that anymore and my kids will just shake their head and draw out a long sigh…

[Doinko]

7 minutes ago, BLI snowman said:

It was probably the most anomalous PNA blocking pattern in modern history across North America.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.mon.pna.wg.jan1950-current.ascii.table

The modified value of -4.39 represents the most extreme value on record, though December 2021 recently gave it a run for its money.

The progression actually started in mid December with a Fraser River blast that hit northern WA around the 18th. Following that, the pattern reset and reset with each successive airmass digging a little more ferociously than the last while a significant amount of jet support existed under the base of the block .

The blast around the 2nd-4th was significant regionally, followed by days of cold onshore flow and occasional wet snow in the lowlands. Then the block reset in full and delivered a massive airmass into the region.

The Friday the 13th blizzard probably rivaled many of the more intense Nor'easters on record. Highly recommend checking out some of the old obs from that day, the wind speeds and temperatures were insane. A few examples:

BLI

https://www.wunderground.com/history/daily/us/or/portland/KBLI/date/1950-1-13

SEA

https://www.wunderground.com/history/daily/us/or/portland/ksea/date/1950-1-13

PDX

https://www.wunderground.com/history/daily/us/or/portland/kpdx/date/1950-1-13

MFR

https://www.wunderground.com/history/daily/us/or/portland/kmfr/date/1950-1-13

The low passed right over PDX around 5pm, and it wound up being one of the worst southerly windstorms on record for the Rogue Valley. And the worst noreaster on record for Whatcom County. Gusts there approached 80mph with temps in the low single digits.

That was followed by a sharp undercut around the 18th which led to a significant ice storm that produced 2-3" of freezing rain for most of NW OR and SW WA. A few mild days followed regionally before another massive airmass dropped straight down out of BC around the 23rd.

The jet stream yo-yoed with a battle zone setting up for a few more days before a very broad and deep trough settled in and produced a massive eastside cold pool at the end of the month which was boosted by the big snowpack. That cold pool helped produce a 15/-10 day locally on the 31st. Low level airmass held on for a few more days into February before the block shifted east for good.

 

9 minutes ago, snow_wizard said:

The thing about Jan 1950 is it was almost completely -PNA driven.  The lowest monthly PNA average of the 20th century.  The N to S temperature gradient was very strong which allowed frequent undercutting systems to spin /push moisture up over the area.  The shallow southward penetration of cold allowed the systems to move inland underneath us instead of them getting shunted way down to CA.  Quite the perfect little setup. For both PDX and SEA to do well.

We had major intrusions of cold on New Years, around the 13th, and then late month.  The warmup before the last Arctic blast set the stage for a major winter storm that produced very heavy snow, ice, and sleet.  For some places the month end storm produced more snow than the blizzard on the 13th.  Palmer which is very near here had 40 inches of snow with that one and had over 60 inches on the ground.  That was caused by marine air interacting with Arctic air seeping in from the passes in East King County.  Tim's area probably had similar. 

Thank you for these write ups! Really informative and great to read! Those obs for BLI on the 13th are insane. Those late month snows look crazy impressive here as well. Looks like a newspaper article from the Beaverton Enterprise says drifts were around 4 feet in Cedar Mill in early February. 

[SilverFallsAndrew]

2 minutes ago, snow_wizard said:

That sound right.  As I mentioned 1950 had a really big gradient.  In 1949 the cold dug much further south.  At SEA 1950 was a lot colder than 1949.

Yeah I mean it was still unthinkably cold by our current standards, we haven’t had a colder month since, but yeah there was a clear north/south gradient, it’s clearly the coldest month in the modern era up there and it’s not even close here. 
 

We probably need the north south gradient to get the really snowy months across the whole region. Those multiple battleground snow events. I’m guessing some of the 1949 and 1930 cold was cold pool and inversion based, which is going to favor Western Oregon for cold anomalies due to geography. 

[Slushy Inch]

Euro run is not it. Can we can do a re-run?

[snow_wizard]

BTW...MJO 7 coming up.  That and SSW are good for us.

[Phil]

1 hour ago, Slushy Inch said:

I’m hyped for the new cold chance! Cascadia, Phil, I had a hunch!

May or may not work out in any given region, but it does seem likely we’ll see another round of high latitude blocking starting mid-Feb, as momentum loss begins and the pacific jet slows (waves break into AK and Greenland again).

Of course AAM will be higher than Jan event, and the PV will be stronger, so odds of a top-tier cold outbreak are lower, but it could still get interesting. But will probably be slightly more progressive overall.

[snow_wizard]

4 minutes ago, SilverFallsAndrew said:

Yeah I mean it was still unthinkably cold by our current standards, we haven’t had a colder month since, but yeah there was a clear north/south gradient, it’s clearly the coldest month in the modern era up there and it’s not even close here. 
 

We probably need the north south gradient to get the really snowy months across the whole region. Those multiple battleground snow events. I’m guessing some of the 1949 and 1930 cold was cold pool and inversion based, which is going to favor Western Oregon for cold anomalies due to geography. 

Right on everything you said here.

[SilverFallsAndrew]

Think about what PDX has done the past 4 winters. 
 

- February 2021 snow/ice event.

- December 2021 snow

- April 2022 snow

- December 2022 ice event sub-freezing high. 
- Late February 2023 snow event 10.8” of snow 

- Sub freezing high in late February. 
- Record low of 18 in late February.

- January 2024 arctic blast. 21/15 day. 
 

Not necessarily a super cold stretch. Last cold season was below average, but none of the other 3 were overall, but some great events. I know Seattle has done well too. 

[snow_wizard]

The ECMWF could be going somewhere really good at the end of the run.  Door is slammed shut on the Pacific.

[snow_wizard]

Just now, SilverFallsAndrew said:

Think about what PDX has done the past 4 winters. 
 

- February 2021 snow/ice event.

- December 2021 snow

- April 2022 snow

- December 2022 ice event sub-freezing high. 
- Late February 2023 snow event 10.8” of snow 

- Sub freezing high in late February. 
- Record low of 18 in late February.

- January 2024 arctic blast. 21/15 day. 
 

Not necessarily a super cold stretch. Last cold season was below average, but none of the other 3 were overall, but some great events. I know Seattle has done well too. 

I don't know why I kept thinking OR didn't well in Dec 2021.  It just seems like everyone down there kept lamenting on how Seattle kept getting all the snow.

[Phil]

4 minutes ago, snow_wizard said:

BTW...MJO 7 coming up.  That and SSW are good for us.

FYI those unfiltered RMMs often lose the MJO due to interference from lower frequency and higher frequency components of tropical forcing (base state/ENSO, ERWs, and CCKWs).

The MJO doesn’t propagate backwards, so if you see that on plots like above, it is because there is interference somewhere.