January 2024 Weather in the PNW (Part I)

[Sunriver Snow Zone]

8 minutes ago, fubario said:

Call me a heretic...but I'm prone to paying some attention to the people who actually make a living at doing this stuff. 

 

 

9:25AM NWS SEATTLE/TACOMA, WA

LONG TERM /TUESDAY THROUGH FRIDAY/...The active pattern
continues through the middle of next week, potentially turning
much colder and more wintry even across the lowlands by the end
of the workweek.

Additional shortwave energy looks to move through the backside of
the longwave trough Tuesday and Wednesday, keeping widespread
precipitation over the region. Confidence is lower in exactly how
deep the trough and associated cold air will dig across the
Pacific Northwest through this time, with the consensus remaining
unchanged for a prolonged heavy snowfall event for the Cascades
and passes. Long-range ensemble mean and the NBM both bring storm
total snowfall of up to several feet over the Cascades by
Thursday morning, which will make travel difficult to dangerous at
times. Snow levels remain above 1000 feet through Wednesday,
which will keep precipitation mostly in the form of rain over the
lowlands, with the exception possibly being western Whatcom and
Skagit Counties where colder air will filter in from the north
first.

As previously mentioned, a large degree of uncertainty remains in
timing and placement of moisture with these shortwaves in relation
to the push of cold air with a sub-Arctic front that pushes
southward out of British Columbia during the Wednesday night into
Thursday timeframe. General consensus is for the best chances for
lowland snow is mostly Thursday into Friday after this front
pushes southward into Western Washington. Greatest snowfall totals
and probability for accumulating lowland snow continues to be
north of Seattle across northwestern Snohomish County and western
Whatcom and Skagit Counties. Here are current 72-hour period
snowfall probabilities across the lowlands ending 4 PM Friday:
* 75-85% chance of greater than 0.1" of snow
* 50-60% chance of greater than 1" of snow
* 20-30% chance of greater than 4" of snow (10-15% from Everett
  to Seattle Southward.)
* 5-10% chance of greater than 8" of snow (<5% from Everett to
  Seattle Southward.)

We continue to monitor the potential for extreme cold late next
week, with growing confidence for at least the coldest
temperatures thus far this winter season as a strong Arctic
surface high noses southward east of the Canadian Rockies.
Uncertainty continues in how far south and west of this high the
core of the cold air digs. The temperature gradient is likely to
be quite large along this front, regardless of how far south it
makes it through the end of the week. NBM probability for low
temperatures below 20F Thursday night, Friday night, and Saturday
night is roughly around 50%. And the probability for lows in the
single digits is around 20% during this time, obviously lower for
locations immediately along waterfronts.

Forecasters miss out in snow sometimes, Dec 2016, Feb 2023 Portland didn't have much warning for the snowstorm it got, and it absolutely f'd everything up, and December 2009. And probably other things Im forgetting.

 

Obviously different but this time will be no exception!

[snow_wizard]

Brrrrr.

[Doinko]

3 minutes ago, Meatyorologist said:

wrong.

Yeah it just cuts into the block

[TacomaWx]

Just now, snow_wizard said:

Brrrrr.

Terrible run for sure. It’s over 100%

[snow_wizard]

1 minute ago, lowlandsnow said:

Way better than GFS worse than the Canadian though. Oh well I guess we might not have a Jan 1950 repeat.

GEM and ECMWF both had great improvements vs 0z.

[Randyc321]

3 minutes ago, Cold Snap said:

Looks like this is not over yet! GFS seems like it is out to lunch.

Hopefully having several drinks for lunch.  

 

[TT-SEA]

High of 22 in Seattle on Friday.   

[iFred]

1 minute ago, Deweydog said:

Euro slowly but surely catching on.

Im making an educated guess that by Monday evening that the Euro will have picked up on what the others have been on and we’ll all get some nice cold rain on Thursday.

[snow_wizard]

That little short wave to the west could be a huge player.

[TacomaWx]

Just now, TT-SEA said:

High of 22 in Seattle on Friday.   

Kind of disappointing this is a strong N/S gradient run. Seeming like the regional stuff is seemingly disappearing. 

[TT-SEA]

Major moisture plume parked along arctic boundary by next Saturday.  

[MikeInEverett]

That block is just hanging by a thread. I feel like we’re just dying a slow death with these possibilities. I really really hope I’m wrong. 

[fubario]

1 minute ago, Sunriver Snow Zone said:

Forecasters miss out in snow sometimes, Dec 2016, Feb 2023 Portland didn't have much warning for the snowstorm it got, and it absolutely f'd everything up, and December 2009. And probably other things Im forgetting.

 

Obviously different but this time will be no exception!

Right. Weather forecasting is HARD! Even for the people who go to school for it. I'm just saying I think there's value in paying attention to these folks...that's all.

[Front Ranger]

Yeah, overall Euro looks like a compromise between CMC and GFS through day 7.

[snow_wizard]

Looks like OR may get slammed.

[ShawniganLake]

1 minute ago, TacomaWx said:

Kind of disappointing this is a strong N/S gradient run. Seeming like the regional stuff is seemingly disappearing. 

Usually means someone in the middle gets buried 

[snow_wizard]

Just now, MillCreekMike said:

That block is just hanging by a thread. I feel like we’re just dying a slow death with these possibilities. I really really hope I’m wrong. 

Look at trends.  Better run than 0z.

[Doinko]

Temps crash with an approaching system to the south. 30 to 20 at PDX in 6 hrs

[snow_wizard]

Uh guys....

[Frontal Snowsquall]

3 minutes ago, snow_wizard said:

That little short wave to the west could be a huge player.

Incoming snowstorm for next weekend!

[SeanNyberg]

Euro 12z

Seattle Thurs Temp +12 run to run

Seattle Friday Temp Unchanged run to run

Seattle Saturday Temp -7 run to run

Euro is slightly delayed, but stronger than before.

[TT-SEA]

Oregon is in sweet spot next Saturday with cold air to the north and moisture to the south. 

[GobBluth]

The block is going to reassert once the Saturday wave passes...

[snow_wizard]

This run is worlds better actually.

[Weiner Warrior]

[Frontal Snowsquall]

2 minutes ago, snow_wizard said:

Uh guys....

Big snowstorm incoming!

[snow_wizard]

I think we are in for a delightful ride.

[Doinko]

@TigerWoodsLibidogets nailed. Heavy snow with a temp of 17!

 

[SnowWillarrive]

1 minute ago, TT-SEA said:

Oregon is in sweet spot next Saturday with cold air to the north and moisture to the south. 

Good to be on the north side of that. Will need the wiggle room this far out. 

[westcoastexpat]

[TT-SEA]

Just now, SnowWillarrive said:

Good to be on the north side of that. Will need the wiggle room this far out. 

If it moves this far north then Oregon would be screwed.

[Prairiedog]

Just now, Frontal Snowsquall said:

Big snowstorm incoming!

Looks like pretty strong Gorge outflow.  That could create quite a wonderful mess if it all comes together. 

[Frontal Snowsquall]

2 minutes ago, TT-SEA said:

Oregon is in sweet spot next Saturday with cold air to the north and moisture to the south. 

The sweet spot is going to change as we get closer to the event. But PDX North is sitting pretty right now.

[Ken in Wood Village]

Just now, Frontal Snowsquall said:

Big snowstorm incoming!

The low will fluctuate between now and then. If it moves a little North, big snowstorm for the Portland area with big East winds which could make it a blizzard. We are still to far out to know what will happen. 

[Winterdog]

Rob will be pleased with that cold pool in eastern Washington.  It looks like a slow but dry warmup for most of us in Western Washington.

[TT-SEA]

Just now, Frontal Snowsquall said:

The sweet spot is going to change as we get closer to the event. But PDX North is sitting pretty right now.

If it happens at all.   We are nowhere close to model consensus yet.  

[Prairiedog]

1 minute ago, Prairiedog said:

Looks like pretty strong Gorge outflow.  That could create quite a wonderful mess if it all comes together. 

Gap winds too?

[Blizzard777]

15 minutes ago, snow_wizard said:

GFS is to progressive with the base of the block.

We 2 out of 3 on the big three models going cold now.

 

[snow_wizard]

Pretty colors are back!

[TT-SEA]

Clipper snow next Sunday.