PNW February 2023 Weather Discussion - Meteorological winter finale

[Slushy Inch]

11 minutes ago, WhoNeedsAC said:

Seriously, what is up with these long-range models? It seems like there's been a major snowstorm 2 weeks to 10 days out for half the winter. Do they not take historical climatology into consideration at all? Or is it a scale thing, like the entire Willamette Valley is modeled at 5,000 feet?

I don’t think it’s been that often.

[Phil]

I might have to jump on the El Niño bandwagon soon. Downwelling OKW looking very likely now. At the very least, this La Niña is toast.

[WhoNeedsAC]

8 minutes ago, MossMan said:

I need AC in the summer! 

That's the joke.

[MossMan]

Getting a little breezy. Hopefully it will increase substantially soon. 

[Doinko]

How's the 18z Euro?

[TT-SEA]

18Z ECMWF

[Doinko]

1 minute ago, TT-SEA said:

18Z ECMWF

Slightly worse than the 12z. Hoping the 00z is a bit better

[Perturbed Member]

Low is weaker on the 18z, less juice to work with. 

[MossMan]

2 minutes ago, TT-SEA said:

18Z ECMWF

Almost very slightly better for my area. 

[joelgombiner]

38 minutes ago, Phishy Wx said:

GFS GFS'n

 

Are we really trusting a forecast system that doesn't even know how to use HTML on their website? 

[Perturbed Member]

Last 4 runs. 18z is a noticeable step backwards for PDX. 

[Requiem]

6 minutes ago, TT-SEA said:

18Z ECMWF

Sad

[Deweydog]

Breezy!

[GHweatherChris]

Things are looking more favorable for my backyard.

[Requiem]

1 minute ago, Perturbed Member said:

Last 4 runs. 18z is a noticeable step backwards for PDX. 

Crossing my fingers for a decent 00Z run but it's frustrating how one step forward two steps backwards tracking a relatively minor snow event is. Unfortunate how snow starved we are...

[Cold Snap]

4 minutes ago, joelgombiner said:

Are we really trusting a forecast system that doesn't even know how to use HTML on their website? 

44 mile resolution on the GFS in the long range lol no wonder it performs so bad in the long range here.

[SilverFallsAndrew]

7 minutes ago, Perturbed Member said:

Last 4 runs. 18z is a noticeable step backwards for PDX. 

Best yet for SLE and here. lol

[Dave]

Hmm. Still no WWA or even a special weather statement. Meanwhile, a WWA has been issued for Medford. 

[thickhog]

8 minutes ago, Requiem said:

Crossing my fingers for a decent 00Z run but it's frustrating how one step forward two steps backwards tracking a relatively minor snow event is. Unfortunate how snow starved we are...

Maybe the pro mets know what they’re doing

 

[Slushy Inch]

20 minutes ago, TT-SEA said:

18Z ECMWF

I’ll wait for EPS before reacting.

[TT-SEA]

4 minutes ago, Slushy Inch said:

I’ll wait for EPS before reacting.

Not sure what to make of it for the EPSL... it shows most of that snow falling before 4 p.m. tomorrow but temps at 4 p.m. are not very cold yet.

 

[ShawniganLake]

25 minutes ago, TT-SEA said:

18Z ECMWF

Oh wow. Substantial improvement. Looks like my location could be inline for 3-6”.  

[ShawniganLake]

5 minutes ago, Slushy Inch said:

I’ll wait for EPS before reacting.

Meh. Within 72hrs now.  Model accuracy swings toward the operationals. 

[Dave]

1 minute ago, TT-SEA said:

Not sure what to make of it for the EPSL... it shows most of that snow falling before 4 p.m. tomorrow but temps at 4 p.m. are not very cold yet.

 

Could be a situation where the temps fall under a heavy shower, then rebound after it passes. 

[Cold Snap]

It’s starting.

[joelgombiner]

56 minutes ago, Cold Snap said:

44 mile resolution on the GFS in the long range lol no wonder it performs so bad in the long range here.

Some quick mapping in QGIS shows what 44-mile resolution looks like. The image on the left shows the topography of western North America, overlayed with a 44x44 mile grid. The image on the right shows the same view, with down-sampled topography created by taking the median elevation value in each grid cell. This is close to what that the long-range GFS apparently sees. Note the total absence of the Olympics, and the overall crudeness of the topography. 

Due to interest in this, I went ahead and made a second version with 15 greyscale color classes to better depict the coarse 44-mile topography on the right. This makes it a bit harder for my eye to pick out the terrain patterns, but is more accurate for what the GFS actually sees. 

Another thought is that the placement of the grid relative to the topographic features makes a big difference for the final output. Are the Olympics centered in one grid-cell or split between four? 

[Phishy Wx]

gotta love Spokane AFD forcaster humor

 

Wednesday evening through Thursday: The main story through Thursday 
is cold and breezy conditions. Temperatures will bottom out to as 
low as 0-10F in most places Wednesday night. The coldest locations 
Wednesday night will be Deer Park, Bonners Ferry, and Lookout Pass 
with a 44, 28, and 99 % chance of below 0F temperatures 
respectively. With winds still gusting as high as 40 mph in spots 
Wednesday night, wind chills could be as low as -15F to 
-20F (especially in the Purcell Trench to the Upper Columbia Basin).

Temperatures Thursday will only reach into the teens as cold air 
advection from the northeast continues. Wind gusts wane below 25 mph 
Thursday night as the pressure gradient relaxes, allowing for 
another night of cold temperatures. The coldest spot Thursday night 
will be Northern Idaho, particularly Bonners Ferry. The probability 
of less than 0F for Bonners Ferry Thursday night is 72 %. Deer Park 
has a 43 % chance of temperatures less than 0F again as a stronger 
surface inversion will form with less surface wind. Luckily Spokane 
has a 0 percent chance of being below zero because this forecaster 
is over winter. 

[SouthHillFrosty]

2 minutes ago, joelgombiner said:

Some quick mapping in QGIS shows what 44-mile resolution looks like. The image on the left shows the topography of western North America, overlayed with a 44x44 mile grid. The image on the right shows the same view, with down-sampled topography created by taking the median elevation value in each grid cell. This is close to what that the long-range GFS apparently sees. Note the total absence of the Olympics, and the overall crudeness of the topography. 

 

Can we pin this?

[ShawniganLake]

2 hours ago, TT-SEA said:

Andrew here... so we are all just going to completely ignore the Sunday event?? 

Oh wow.  Looks like another solid thumping of snow here. 2-4”. 

[HuskyMaestro]

3 minutes ago, joelgombiner said:

Some quick mapping in QGIS shows what 44-mile resolution looks like. The image on the left shows the topography of western North America, overlayed with a 44x44 mile grid. The image on the right shows the same view, with down-sampled topography created by taking the median elevation value in each grid cell. This is close to what that the long-range GFS apparently sees. Note the total absence of the Olympics, and the overall crudeness of the topography. 

 

This is really cool.

With the map on the left, my imagination makes it look like if WW, Willamette Valley, and the Columbia Basin went underwater and turned the Olympics into an island and the Cascades into a giant peninsula. 

[snow maniac]

Been dry here all day today just breazy. 

[SilverFallsAndrew]

IDK if it has been mentioned, but there has been a Winter Storm Watch issued for the Southern Oregon Coast from North Bend to Brookings. This is for accumulating snow to sea level. 

Edited February 21, 2023 by SilverFallsAndrew

[joelgombiner]

5 minutes ago, SouthHillFrosty said:

Can we pin this?

Caveat that I do not really understand how the GFS model works, but I interpret "44-mile" grid spacing as meaning something similar to the topography shown above. 

[Phil]

12 minutes ago, MossMan said:

Getting a little breezy. Hopefully it will increase substantially soon. 

You want wind? We’ve had plenty to share.  This upcoming pattern will probably produce several 50-60+mph days over the next 2 weeks. 

 

 

[Timmy]

Gonna be a tough pill to swallow here. Anyone from the Dalles wanna commiserate ?

Edited February 21, 2023 by Timmy

[SilverFallsAndrew]

2 minutes ago, Timmy said:

Gonna be a tough pill to swallow here. Anyone from the Dalles wanna commiserate ?

Bet you do well Sunday morning though. 

[ChrisEl Elyon]

Had gusts of 49 mph here around Seattle City Center/Downtown Seattle area.

[Perturbed Member]

The  GEM, RGEM and NAM have generally produced solutions where PDX is too far north to get much if any snow Wednesday-Thursday, the 12z UKMET also moved the bullseye well south of PDX whereas the 00z run had it right over the metro. 

With the 18z euro also scaling back on snow in PDX and producing higher totals around SLE and south it raises a question of if this is just noise and meaningless fluctuations or if this will end up being the start of a trend. 

The ICON and GFS are the two remaining models that produce very significant totals in PDX metro. 

I suspect 1-2 inches of snow is pretty doable around the north WV and maybe more likely than not, but it looks like some areas can end up missing out still.

[gusky]

Looks like I might get lucky this time... headed to Quinault on Wednesday and should get at least a bit of snow. (NAM snow depth valid 7am Thursday PST)

[ShawniganLake]

24 minutes ago, Phil said:

You want wind? We’ve had plenty to share.  This upcoming pattern will probably produce several 50-60+mph days over the next 2 weeks. 

 

Didn’t see any Sasquatch in this.  But Phil wins. Much windier than mossman’s house