January 2024 Weather in the PNW (Part I)

[Kolk1604]

I spy improvements 

[Weiner Warrior]

Portland getting some mixed action

[awright-31]

This looks not bad

[lowlandsnow]

Much better than GFS

[snow_wizard]

Looking better so far.  Much like the 6z EPS control...at least as far as Weatherbell is.

[Front Ranger]

That block at the end of the GEM is just insane. All the way from Greenland to AK, sagging deep into Canada. -60 temps in MT.

[Frontal Snowsquall]

1 minute ago, Kolk1604 said:

I spy improvements 

Here we go!!!!!

[Meatyorologist]

AL looks a tad less progressive

[fubario]

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.

[Deweydog]

HOT TAKES!!!

[Slushy Inch]

2 minutes ago, Kolk1604 said:

I spy improvements 

Indeed!

[Phishy Wx]

1 minute ago, Front Ranger said:

That block at the end of the GEM is just insane. All the way from Greenland to AK, sagging deep into Canada. -60 temps in MT.

The Baffin Bumper

[MR.SNOWMIZER]

1 minute 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.

This forecast is based on lastnight runs.

[snow_wizard]

2 minutes ago, Front Ranger said:

That block at the end of the GEM is just insane. All the way from Greenland to AK, sagging deep into Canada. -60 temps in MT.

Full comeback for that model.

I have two words...Graph Cast.

[TT-SEA]

12Z ECMWF way warmer for Thursday than its 00Z run but that seems be due to a delay because its farther west... and wetter.  

[Slushy Inch]

West!

[snow_wizard]

2 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.

You underestimate the knowledge on here.  I've been doing this longer than some of the people at the NWS have been alive.

[SeanNyberg]

Euro looking better than GFS.

Still far from where these models were just two days ago.

[SouthHillFrosty]

Just now, TT-SEA said:

12Z ECMWF way warmer for Thursday than its 00Z run but that seems be due to a delay because its farther west... and wetter.  

 

[Slushy Inch]

Going to be a good run for western WA

[OysterPrintout]

go euro go was it over when the germans bombed pearl harbor??

[RCola]

West is best! C'mon, Euro! 

[Front Ranger]

1 minute ago, snow_wizard said:

Full comeback for that model.

I have two words...Graph Cast.

I haven't caught up...is today's edition fully onboard?

[snow_wizard]

1 minute ago, TT-SEA said:

12Z ECMWF way warmer for Thursday than its 00Z run but that seems be due to a delay because its farther west... and wetter.  

Back digging delays the cold.  Good in this case.

[snow_wizard]

Just now, Front Ranger said:

I haven't caught up...is today's edition fully onboard?

Last night was frigid.  Not updated yet today.

[Randyc321]

6 minutes ago, Frontal Snowsquall said:

12z EURO Day 4

Love this inside 5 days!  

[TT-SEA]

Just now, SouthHillFrosty said:

 

Just delayed... cold air is coming down late in the day and it ends up being more snowy.  

[Meatyorologist]

5 minutes ago, Meatyorologist said:

AL looks a tad less progressive

wrong.

[Frontal Snowsquall]

2 minutes ago, Slushy Inch said:

West!

Better over water trajectory with the Arctic Front. It will result in more snow.

[Doinko]

1 minute ago, Front Ranger said:

I haven't caught up...is today's edition fully onboard?

The latest run, last night's 00z looked like -16 to -20c 850mb temps and around -25/26c in the Columbia Basin

[Phishy Wx]

lol FFS I gotta invest another day in this 

[fubario]

Just now, snow_wizard said:

You underestimate the knowledge on here.  I've been doing this longer than some of the people at the NWS have been alive.

No insult intended to contributors like yourself who know your sh**. I just don't see much attention given to our NWS peeps...that's all.

[snow_wizard]

GFS is to progressive with the base of the block.

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

[Cold Snap]

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

[Deweydog]

Euro slowly but surely catching on.

[snow_wizard]

Just now, fubario said:

No insult intended to contributors like yourself who know your sh**. I just don't see much attention given to our NWS peeps...that's all.

Very fair statement.

[Slushy Inch]

3 minutes ago, SeanNyberg said:

Euro looking better than GFS.

Still far from where these models were just two days ago.

But moving in the direction of old euro runs

[lowlandsnow]

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

[Weiner Warrior]

[iFred]

5 minutes ago, snow_wizard said:

Full comeback for that model.

I have two words...Graph Cast.

It’s one word and Graphcast uses the Euro.