PNW December 2022, winter might be coming; but mostly canceled.

[fubario]

10 minutes ago, 12345WeatherNerd said:

don't want

[TT-SEA]

2 minutes ago, Brian_in_Leavenworth said:

GEFS looks like it wants to have the Westerlies break through around day 9?  Quite a change from other runs.  18Z vs 00Z

And the Jetstream, same comparison 

 

 

It seems like the GEFS is so much more volatile that the EPS after about day 7.  

[Slushy Inch]

3 minutes ago, Brian_in_Leavenworth said:

GEFS looks like it wants to have the Westerlies break through around day 9?  Quite a change from other runs.  18Z vs 00Z

And the Jetstream, same comparison 

 

 

More chance for northerly flow to continue

[WeatherGeek2022]

8 minutes ago, umadbro said:

Is this the regional event we’ve all been waiting for?

feeling like a very familiar AR transition event. 

[MikeInEverett]

Blue sky!!

[Hawksfan2008]

The GFS/GEFS has walked to the end of the plank…good chance it falls off the deep end with the 00z run (in a good way)

[SouthHillFrosty]

Ayo

[Requiem]

1 minute ago, SouthHillFrosty said:

Ayo

Is there an ice accumulatio ensemble mean by any chance?

[Front Ranger]

1 hour ago, MWG said:

Every Judah gets his day.

[fubario]

1:15pm Seattle NWS discussion..

 

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...An active period of
weather is expected next week, with uncertainty regarding the
troughing trajectory located across British Columbia over the
weekend. Guidance has slowly come into at least slightly better
agreement in the weather pattern, which is discussed in this
section.

The ensemble members for ECMWF/GFS/CMC have slowly come into a bit
better agreement of stalling the colder air on Sunday into British
Columbia, with more moderate temperatures for the Pacific
Northwest. This better agreement is noted on the WPC Cluster
Analysis for the 24 hour period ending 00z Monday. GFS continues
to have a bit more in the way of ridging influence during this
period, compared to ECMWF/CMC, although the difference on Sunday
isn`t overly significant so there isn`t that much spread in
temperatures (only 5 degree spread on NBM using 25-75th
percentile). However, with the boundary slowly sliding south, the
potential for increasing Fraser Outflow exists on Sunday, for a
bit better of a chance of rain/snow mix, primarily for
Whatcom/Skagit Counties with lower snow levels in this area to
near 500 feet.

Troughing will continue to be focused over British Columbia into
Monday, with a bit more in the way of uncertainty into
precipitation type and the amount of colder air that filters into
Western Washington. NBM snow levels on Monday range generally from
500-1200 ft, with surface base snow levels for Whatcom County.
Guidance/ensembles slowly introduce the better chance of
rain/snow beginning Monday morning with likely lingering showery
precipitation. Another weather system may move through the area
Monday night-Tuesday timeframe for another round of precipitation,
with increasing potential for accumulating snowfall for portions
of the lowlands. By Wednesday there is certainly a bit more
significant spread in the guidance as to the extent of troughing
influence across the Pacific Northwest, or rather ridging that
builds offshore. Compared to the ensemble mean, approximately 50%
of ECMWF/GFS/CMC ensembles lean towards a colder solution, and 50%
a bit warmer due to additional ridging. Due to this uncertainty
and spread in guidance have opted to keep with NBM forecast.
Either way, colder temperatures are expected on Wednesday with
increasing northerly flow, potentially setting up another
overrunning event later in the week. It will be important to
continue monitoring forecasts over the next week. JD

&&

[Joshua Lake Oswego]

12 minutes ago, Requiem said:

That's the one saving grace-- models have been persistent with some pretty great low level cold out of the Gorge. Unfortunately the nature of our overrunning systems means I'd hedge bets on it being ZR.

Exactly. I would prefer it not to be below freezing for that reason. The south wind will win out over the gorge outflow for most of the metro area.

[T-Town]

2 hours ago, Deweydog said:

In the meantime, can someone ID this?

Not sure. Caught a glimpse of it here earlier, but very brief and then it was gone. 

[Deweydog]

Did a bit of a deeper dive on this thing and it looks like it does have quite a few similarities to January 2004, at least with some of the current realities thrown out by the models. The precursor pattern is starkly different though.

[dhoffine]

4 minutes ago, Deweydog said:

Did a bit of a deeper dive on this thing and it looks like it does have quite a few similarities to January 2004, at least with some of the current realities thrown out by the models. The precursor pattern is starkly different though.

What happened in January 04 for us new folks?

[Requiem]

3 minutes ago, dhoffine said:

What happened in January 04 for us new folks?

The ice storm that never ended in parts of PDX. I believe everywhere north and east of the west metro up to Bellingham(?) had snow, though. 

[Ziess]

4 minutes ago, dhoffine said:

What happened in January 04 for us new folks?

January 2004 Storm

[Deweydog]

1 minute ago, dhoffine said:

What happened in January 04 for us new folks?

It was a major low level blast which was quickly followed by a significant overrunning event which heavily affected both metro areas, particularly Portland with the ice. 

[BLI snowman]

Just now, Requiem said:

The ice storm that never ended in parts of PDX. I believe everywhere north and east of the west metro up to Bellingham(?) had snow, though. 

The Portland metro had a widespread 6-8" of snow with that storm on the 6th before the transition to freezing rain, which was the same or slightly higher than what most of western WA got. The snow extended down to the mid-Willamette Valley.

[SilverFallsAndrew]

1 minute ago, Requiem said:

The ice storm that never ended in parts of PDX. I believe everywhere north and east of the west metro up to Bellingham(?) had snow, though. 

We had a lot of snow in Silverton east of Salem. And ridiculous ice. 

[TigerWoodsLibido]

Looking pretty dynamic up north.

[flya00]

Kelowna, BC. It snowed last night, not sure the amount.

[jakerepp]

2 minutes ago, flya00 said:

Kelowna, BC. It snowed last night, not sure the amount.

What trees are those that still have leaves??

[Deweydog]

8 minutes ago, Ziess said:

January 2004 Storm

That was actually in the lead up pattern with a surface low that tracked well to the south. Kinda caught everyone a little flat footed.

[Gradient Keeper]

January 2004 we had two events. The first around New Years, and the more prolific one a bit later. Out this way closer to the Gorge we had a ton of sleet, not much zr, then 8" of snow and a brutal arctic blast. High temp at my house was 14.9, low 9.5. Pasco dropped to -25. It was fun!

00z ECMWF in 5 hours 45 minutes

[Kolk1604]

1 minute ago, Gradient Keeper said:

January 2004 we had two events. The first around New Years, and the more prolific one a bit later. Out this way closer to the Gorge we had a ton of sleet, not much zr, then 8" of snow and a brutal arctic blast. High temp at my house was 14.9, low 9.5. Pasco dropped to -25. It was fun!

00z ECMWF in 5 hours 45 minutes

And then we torched the rest of the way 

[TT-SEA]

25 minutes ago, Deweydog said:

Did a bit of a deeper dive on this thing and it looks like it does have quite a few similarities to January 2004, at least with some of the current realities thrown out by the models. The precursor pattern is starkly different though.

Just checked locally... that was sure a slow transition.   The cold spell lasted for 10 days... it finally spiked into the 50s on the 9th.     Tons of snow out here on 1/7 and 1/8 which must be similar to the event shown for next Wednesday/Thursday.

After that... most of the days were in the 50s out here the rest of January.

[Gradient Keeper]

January 2004 I made a big mountain of snow in my backyard that did not melt until the 30th! We had snow on the ground for two weeks.

[Front Ranger]

1 hour ago, umadbro said:

Sorry folks, I have to accept blame for the upcoming non event. Yesterday I went and bought covers for my outdoor faucets and sand bags for the bed of my truck. I accept full responsibility for my actions.

You will need them. Eventually.

- Dewey

[BLI snowman]

1 minute ago, Gradient Keeper said:

January 2004 I made a big mountain of snow in my backyard that did not melt until the 30th! We had snow on the ground for two weeks.

I remember the parking lot piles hanging around until March that year, despite the mild back half of winter. All the ice had really helped to encase and glaciate the snow and made the piles of it tough to melt.

[TT-SEA]

2 minutes ago, BLI snowman said:

I remember the parking lot piles hanging around until March that year, despite the mild back half of winter. All the ice had really helped to encase and glaciate the snow and made the piles of it tough to melt.

Lovely spring in 2004.    And summer too.  

[Front Ranger]

25 minutes ago, BLI snowman said:

The Portland metro had a widespread 6-8" of snow with that storm on the 6th before the transition to freezing rain, which was the same or slightly higher than what most of western WA got. The snow extended down to the mid-Willamette Valley.

And that was after a New Year's storm that dropped a widespread several inches+ from the Willamette Valley to south Puget Sound. 

In Tacoma, we also picked up a couple inches with the Arctic front on 1/4 (?).

[BLI snowman]

1 minute ago, TT-SEA said:

Lovely spring in 2004.    And summer too.  

Late August was beautiful. 

I think I blocked the rest of it from my memory.

[T-Town]

Jaya is monitoring. 
 

 

[WildrootParable]

13 minutes ago, jakerepp said:

What trees are those that still have leaves??

This was a really weird year for trees dropping their leaves. I've got alders that are STILL hanging on. Our apple tree still has some remaining, too. Very strange. 

[BLI snowman]

1 minute ago, Front Ranger said:

And that was after a New Year's storm that dropped a widespread several inches from the Willamette Valley to south Puget Sound. 

In Tacoma, we also picked up a couple inches with the Arctic front on 1/4 (?).

That was a real action packed 10 day stretch. Felt like the Twilight Zone after the previous half decade.

There was also another big, unforecasted snowstorm on December 29th that slammed the central Willamette Valley. Salem area had 4-10" and the south suburbs of Portland actually did well. Then there was a nice little BC slider on the 30th-31st that dropped a few inches across the entire I-5 corridor up to YVR. 

[Nov1985]

18z ECMWF past 2 to Sat nt

 

[Front Ranger]

Just now, WildrootParable said:

This was a really weird year for trees dropping their leaves. I've got alders that are STILL hanging on. Our apple tree still has some remaining, too. Very strange. 

Same here on the Front Range. We went through a similar, rapid transition from summery weather through most of October to wintry weather in November, though not as extreme as the PNW. 

Some trees that are usually bare by late October still have basically dead leaves hanging on.

Thanks, Tonga.

[Nov1985]

18z ECMWF last few frames.

 

[Deweydog]

21 minutes ago, TT-SEA said:

Just checked locally... that was sure a slow transition.   The cold spell lasted for 10 days... it finally spiked into the 50s on the 9th.     Tons of snow out here on 1/7 and 1/8 which must be similar to the event shown for next Wednesday/Thursday.

After that... most of the days were in the 50s out here the rest of January.

Yeah, that cold period started right after Christmas with a funky overrunning/suppressed jet system down the valley, then a benign little clipper on the 30th with flat gradients down here dropped 2-3 inches. That was followed by the big valley event on 1/1 which transitioned to a lot of cold onshore flow. We had a lot of snow in the air here on 1/3 leading up to the wind shift on 1/4.

So the lead up was very different but anomaly placement and vast separation from the accompanying block is pretty similar. Westerlies were already undercutting effectively as the low level cold arrived. I don’t think there was much of a -NAO component though. 

[SouthHillFrosty]