PNW February 2023 Weather Discussion - Meteorological winter finale

[Gradient Keeper]

6z GFS Op Day 10+ Long range looking to drop another cold, continental air mass on us.

[Phil]

1 hour ago, SilverFallsAndrew said:

I can’t believe how much rain/snow California has had. It’s almost livable again. 

Yeah, pretty major shift in the SPMM/NPMM dipole & Hadley/z-cells compared to recent years. Lends credence to the idea that La Niña is ending and the 4CH will be smaller in 2023.

[Phil]

Wow.

We’ll have to see if a trade burst follows as the MJO orbits back into the IO, but the fact there’s little if any indication of the low pass/niña standing wave is pretty incredible.

[Phil]

Also note the rising integral of AAM on the EPS over the next couple of weeks.

[Phil]

Check out these D8-14 500mb analogs.  

[Christensen87]

Winter Weather Advisory for EPSL, calling for up to 10 inches by Sunday night. I feel like it should be upgraded to a Winter Storm Watch. 

[MillCreekMike]

When it said 10 inches for EPSL I figured that meant through Tuesday or something but nope it’s only through 10pm Sunday. Pretty bullish! Which is good to see.

[TT-SEA]

8 minutes ago, MillCreekMike said:

When it said 10 inches for EPSL I figured that meant through Tuesday or something but nope it’s only through 10pm Sunday. Pretty bullish!

ECMWF only shows .3 to .4 in total precip for the EPSL through that time,    And shows temps in the 40s on Sunday afternoon.   They are going the other way now.   Not sure how there could be 10 inches of snow in the EPSL in the next 36 hours.

[TT-SEA]

Reading the details of the WWA... I think the high end of the amounts might be up north in the foothills where the c-zone reaches the Cascades near Gold Bar on Sunday afternoon.    Its pretty silly to lump places like Maple Valley and Fall City in with that small area and just blanket say the entire EPSL could see 10 inches of snow.    It doesn't represent the reality of the situation.  

[Timmy]

7 minutes ago, TT-SEA said:

ECMWF only shows .3 to .4 in total precip for the EPSL through that time,    And shows temps in the 40s on Sunday afternoon.   They are going the other way now.   Not sure how there could be 10 inches of snow in the EPSL in the next 36 hours.

Can you post the 06z euro through tomorrow mornings event ?

[TT-SEA]

Looking at the ECMWF... the circled area is why they put the high end at 10 inches.    Most of the EPSL has no chance of reaching 10 inches by Sunday evening.

[TT-SEA]

2 minutes ago, Timmy said:

Can you post the 06z euro through tomorrow mornings event ?

 

[GHweatherChris]

The WWA's they put up, the one for ESPL up to 10" and in my area for up to 6" aren't gospel, they just want people to know of any potential for areas in the advisory zones, scrutinizing them for putting them up is pointless.

[Blizzard777]

8 hours ago, SunAndSnow said:

What is this? And where can I buy one? 

Look up “storm glass” on the internet and that will lead the way.  Just fun crystals that react to the weather.   Mine doesn’t work all the time but hers really reacts to the weather. 
 

20* brrrrrrr

[TT-SEA]

The unfortunate part of that WWA is that it will hurt their credibility the other way.    Only a very tiny percentage of the people in the EPSL live where 10 inches is even remotely possible.    But I guess that is better than what happened in Portland where no one was prepared because the NWS didn't say anything about the impending snowstorm.

[Timmy]

2 minutes ago, TT-SEA said:

The unfortunate part of that WWA is that it will hurt their credibility the other way.    Only a very tiny percentage of the people in the EPSL live where 10 inches is even remotely possible.    But I guess that is better than what happened in Portland where no one was prepared because the NWS didn't say anything about the impending snowstorm.

more bullish on the nam

[MillCreekMike]

21 minutes ago, TT-SEA said:

ECMWF only shows .3 to .4 in total precip for the EPSL through that time,    And shows temps in the 40s on Sunday afternoon.   They are going the other way now.   Not sure how there could be 10 inches of snow in the EPSL in the next 36 hours.

Yeah, it includes the town of Snohomish in that which is funny because we usually get pretty close to the same amount as they do over there

[TT-SEA]

The Monday night and Tuesday period looks more snowy on the 06Z ECMWF.   Another WWA will be needed then.    The NAM goes absolutely crazy in this period... but its the NAM and it really struggles with precip placement.  

[TacomaWx]

NWS SEA explanation for not putting up a WWA in the Seattle area is the chance for snow exceeding 1” is 50%…but the possibility of needing to put one up later tonight was something they admitted could happen in the AFD. I’d rather they don’t jinx this anyways. I think we see 1-1.5” tonight here. 

[TacomaWx]

Very cold this morning…got down to 21. About as cold as it gets for the last couple days of February. 

[BLI snowman]

18 at PDX. First low in the teens there since January 2017.

[TT-SEA]

Just now, BLI snowman said:

18 at PDX. First low in the teens there since January 2017.

The power of snow cover! 

[TT-SEA]

12Z ICON for the system tonight.

[luterra]

13 minutes ago, TT-SEA said:

The power of snow cover! 

17 in Corvallis with no snow cover.  I thought snowy areas might be colder.

[MR.SNOWMIZER]

59 minutes ago, MillCreekMike said:

When it said 10 inches for EPSL I figured that meant through Tuesday or something but nope it’s only through 10pm Sunday. Pretty bullish! Which is good to see.

And yet they only show up to 4 inches around the hood canal when every model clearly shows it will be one of the hardest hit areas in western Washington.

[Prairiedog]

19f this am with no snow cover.  Pretty decent for this time of year. 

[SnarkyGoblin]

9 minutes ago, TT-SEA said:

12Z ICON for the system tonight.

I don't believe that convergence zone location for 1 second.

[Cold Snap]

44 minutes ago, TT-SEA said:

Looking at the ECMWF... the circled area is why they put the high end at 10 inches.    Most of the EPSL has no chance of reaching 10 inches by Sunday evening.

When I first saw the WWA I thought the NWS was being very bullish. After seeing this though it makes sense why they would show up to 10 inches. Looks like about 5” for MBY if this verifies.

[MossMan]

Had a low of 22. Currently 25 with some high clouds rolling in. DP 21. 
 

Not much of a -PNA change yet…Sorry Tim! (And me if this was late March) 

[TacomaWx]

We’re down to -1.3F as of yesterday for February. Could finish around -2F this month. Should finally hit 40 today for the first time since Tuesday afternoon but a 42/21 temp spread is still a huge negative departure this time of year. 
 Looking like each of the next 4 days should each have measurable snowfall here. We’re already at 13 days with snowfall this year…amazing how many light snowfalls have occurred this winter. We never got more than 1.2” in a day…however the potential for a 2” event still exists coming up. 

[Hawksfan2008]

12z Meso models all improved. Love to see it as 9/10 times it feels like it goes the other way right before the event. Here we go! 

[TT-SEA]

1 minute ago, SnarkyGoblin said:

I don't believe that convergence zone location for 1 second.

Over Seattle?    That is not a c-zone at that time.   That is just stratiform precip tonight and it must assume that is where temps will be more favorable.

[snowbustcity]

46 minutes ago, TT-SEA said:

 

Ooof…

 

[Hour364Please]

14 minutes ago, TT-SEA said:

12Z ICON for the system tonight.

Looks like Puyallup Valley is in the donut hole again.

Sometimes you're the windshield, sometimes the bug.

[MR.SNOWMIZER]

The ECMWF is struggling with the low placement Tuesday morning.  Every model has it between Olympia and Astoria and ECMWF has it near port angles. 

[TacomaWx]

1 minute ago, TT-SEA said:

Over Seattle?    That is not a c-zone at that time.   That is just stratiform precip tonight and it must assume that is where temps will be more favorable.

From what Mike Snyder was talking about on his briefing yesterday…that’s caused by southerlies off of the Olympic mountains and cascades. Mid level warming creates compression and dries things out a bit. Looks like that’s the reason southern pierce county and places in the NW interior are shadowed. 

[Ken in Wood Village]

1 hour ago, TT-SEA said:

ECMWF only shows .3 to .4 in total precip for the EPSL through that time,    And shows temps in the 40s on Sunday afternoon.   They are going the other way now.   Not sure how there could be 10 inches of snow in the EPSL in the next 36 hours.

You may want to look at the short range models instead of the longer range. Short range should have a better handle on how much moisture these systems will produce. 

[TT-SEA]

2 minutes ago, MossMan said:

Had a low of 22. Currently 25 with some high clouds rolling in. DP 21. 
 

Not much of a -PNA change yet…Sorry Tim! (And me if this was late March) 

Still thinking there will be some sort of pattern change after next weekend... but anything warm seems unlikely.    It seems like the models want to move the focus of the troughing to the east eventually. 

[MR.SNOWMIZER]

Both the nam and fv3 lift this very nice snow band through the sound Tuesday morning. 

[TT-SEA]

1 minute ago, Ken in Wood Village said:

You may want to look at the short range models instead of the longer range. Short range should have a better handle on how much moisture these systems will produce. 

ECMWF is by far the best model for surface details within 3 days.    It may go out to 10 days... but the absolutely best part of the ECMWF is its accuracy with the surface details in the short range.  

[MR.SNOWMIZER]

Bremerton and Shelton both hit 17 degrees.  

[TT-SEA]

2 minutes ago, MR.SNOWMIZER said:

Both the nam and fv3 lift this very nice snow band through the sound Tuesday morning. 

I think Monday night and Tuesday is the main period to watch for some crazy things to happen.  

[TacomaWx]

9 minutes ago, MR.SNOWMIZER said:

The ECMWF is struggling with the low placement Tuesday morning.  Every model has it between Olympia and Astoria and ECMWF has it near port angles. 

We will see if it comes around. Could really be the difference between a decent event or a more significant one. 

[Cold Snap]

FWIW the NBM is showing some 6”+ amounts in the EPSL through next Sunday.

[TT-SEA]

1 minute ago, TacomaWx said:

We will see if it comes around. Could really be the difference between a decent event or a more significant one. 

Yeah... the Tuesday situation is just hard for the models in general.   Similar to the situation in Portland earlier this week.   The potential for a major event somewhere is really high that day and even the ECMWF will bounce around with that scenario.  

[Hour364Please]

I want that sucker to wind up and lift some snow bands from Olympia to Seattle and bury the region in a heavy wet snow.

Let's do this!

[Rubus Leucodermis]

2 hours ago, Phil said:

Check out these D8-14 500mb analogs.  

March 1951… this map is Jim-approved!

[Cold Snap]

5 minutes ago, TT-SEA said:

I think Monday night and Tuesday is the main period to watch for some crazy things to happen.  

Just hoping the precip shield can extend farther east than what these are showing. Though it’s probably very hard for the models to nail exactly how far east it goes.

[MR.SNOWMIZER]

8 minutes ago, TT-SEA said:

I think Monday night and Tuesday is the main period to watch for some crazy things to happen.  

This is Monday morning I posted.  Just noticed 

[Rubus Leucodermis]

06Z models say I probably get 8–10" tonight. Actually they say I get a bit more than that but I’m being conservative in my forecast.