PNW December 2022 - Part II

[Deweydog]

11 minutes ago, BLI snowman said:

Downslope gonna be hungry.

I'm leaning towards just flurries/virga with that first band, and all sleet with the 2nd band once the airmass actually saturates a bit. 

Definitely. Things could start very similar to 12/18/05 where areas just south of the river saw some decent accumulations with the initial warm frontogenesis. I’m sitting at ground zero for the downslope. Looks like Larch should be gusting 50+ for at least 24 hours starting tomorrow afternoon.

[snow_wizard]

Just now, TacomaWx said:

Wow down to 30 at sea tac. It’s gonna get really interesting soon. Getting a good north wind here. 

ECMWF showed 34 or 35 at this time.  Wow wee!!!!

[Winterdog]

Crazy weather.  3” fell before 2am then it warmed up to 33F until it started snowing again around 8am.  Added another 2.5” and the temp is now down to 27F.  Snow has stopped and I have around 5” remaining.  

[JW8]

Just now, snow_wizard said:

From what I can tell temps are running to 3 to 5 colder in areas where the north winds have taken over compared to ECMWF expectations.  Big big deal.

Just wish we had a couple more hours of precip to work with. We can hope for the CZ tonight to overperform though! 

[BLI snowman]

1 minute ago, thickhog said:

I haven’t seen the maps, but I think you can safely cancel your Friday plans if they’re near PDX metro. It’s gonna be nasty.

I have to imagine that I-84 and SR-14 both will be closed on Friday through the gorge. 

[SouthHillFrosty]

Just now, TacomaWx said:

Wow down to 30 at sea tac. It’s gonna get really interesting soon. Getting a good north wind here. 

Rain/snow mix here and 33. I doubt we might be able to get any accumulation with the amount of water everywhere 

[Christensen87]

3 minutes ago, TacomaWx said:

Wow down to 30 at sea tac. It’s gonna get really interesting soon. Getting a good north wind here. 

I keep looking out the window, still raining in Kent at 38 now from 41 ten minutes ago. It's coming!

[snow_wizard]

2 minutes ago, Doinko said:

Euro looks interesting around hr 168. Seems windy

 

For Portland I think big winds will happen a lot sooner than that.

[bainbridgekid]

SEA down to 30 now. 13 degree drop in 90 minutes!

[snow_wizard]

Just now, SouthHillFrosty said:

Rain/snow mix here and 33. I doubt we might be able to get any accumulation with the amount of water everywhere 

Everywhere else has gone to sticking pretty much immediately.  People are really underestimating the power of this cold air advecting in.

[TeacherLori]

Update: Lynnwood at 29 degrees and have now lost the snow globe. Just gentle wafting flakes now...

[TT-SEA]

Fascinating... its not snowing yet at Tiger Summit at 1,300 feet buts its dumping just a couple miles north of there on I-90 which is about 500 feet lower.

[Nov1985]

Just a 13° difference between GFS and ECMWF for tonight's low temps. The ECMWF winter warm bias and GFS winter cold bias was never more evident than the past week.

[Seattle]

1 minute ago, SouthHillFrosty said:

Rain/snow mix here and 33. I doubt we might be able to get any accumulation with the amount of water everywhere 

That's what I thought too, but the temp dropped so fast and you still have fairly heavy precip that I think you should still see accumulation.

[joelgombiner]

1 minute ago, SouthHillFrosty said:

Rain/snow mix here and 33. I doubt we might be able to get any accumulation with the amount of water everywhere 

That was not a problem here with the intensity of precip and the flash freeze. 

[snow_wizard]

Just now, bainbridgekid said:

SEA down to 30 now. 13 degree drop in 90 minutes!

It seems the ECMWF has just underestimated the low level cold pretty much everywhere in the Puget Sound area and Whatcom County.

[snow_wizard]

Just now, joelgombiner said:

That was not a problem here with the intensity of precip and the flash freeze. 

Flash freezes are so cool!

[TT-SEA]

Just now, snow_wizard said:

It seems the ECMWF has just underestimated the low level cold pretty much everywhere in the Puget Sound area and Whatcom County.

Definitely appears that way now... it will be interesting to see what happens to temps in the Seattle area this afternoon when the precip is gone.  

[Doinko]

4 minutes ago, snow_wizard said:

For Portland I think big winds will happen a lot sooner than that.

The WRF GFS is forecasting 55mph gusts for my area Wednesday night.

[yellowstone]

4 minutes ago, snow_wizard said:

Everywhere else has gone to sticking pretty much immediately.  People are really underestimating the power of this cold air advecting in.

Yes absolutely. Didn’t stick on deep puddles and in the road gutters at first but everywhere else, including the road, started almost instantly due to how hard it was coming down (and that the switch happened at exactly 32.0)

[The Blob]

14 minutes ago, Tyler Mode said:

1030 AM

Check out how shallow the cold air is, 28-31 at River level up to about 800', then in the 40s...

It's 45 ar my house and it's at 200'. Gonna be a minute before that cold hits.

[VancouverIslandSouth]

3 minutes ago, TT-SEA said:

Fascinating... its not snowing yet at Tiger Summit at 1,300 feet buts its dumping just a couple miles north of there on I-90 which is about 500 feet lower.

That's the sort of thing that happens a lot near the Fraser outflow. Unusual to see down there though. 

[Cloud]

BFI also down to 30 with snow and visibility of 0.5 mile. 

[BLI snowman]

5 minutes ago, Deweydog said:

Definitely. Things could start very similar to 12/18/05 where areas just south of the river saw some decent accumulations with the initial warm frontogenesis. I’m sitting at ground zero for the downslope. Looks like Larch should be gusting 50+ for at least 24 hours starting tomorrow afternoon.

Yeah, there was a definite E-W divide with that one due to the dry air advection off the foothills. Had a windswept 1/4" in Brush Prairie but areas to the south and to the west of I-5 generally had 1+" and Scappoose had 2-3".

 

[Rubus Leucodermis]

1 hour ago, Gummy said:

Yea, it is giving Seattle a little 1" tease on the way out

Pretty much SOP for an arctic front in Seattle. Have had somewhat better luck up this way, but even so, the recent string of cold snaps with snowy arctic front passages has been a bit like buying winning lottery tickets a few times in a row. At this stage I am probably due to experience a streak of dry blasts.

[Blizzard777]

11 minutes ago, SouthHillFrosty said:

Currently 34 with a daily accumulation of .71in. The euro was way off rain totals

35* here now…I’m chasing you

no sign of snow yet …just heavy drops of rain

[snow_wizard]

Down to 32 at weather station just 4 or 5 miles NW of here.  36 here.

[thisisacreativename]

34.5 here now, every time I go and check it's another bit lower. Full snow shouldn't be long from now.

[Tenochtitlan]

Just measured 9.5" downtown! This is so special, and it makes it all the better that you folks further south are getting in on the action now.

[SouthHillFrosty]

3 minutes ago, snow_wizard said:

Flash freezes are so cool!

I currently have over a quarter of an inch  of standing water… I hope not 

[CloudJunkie]

43, gusty, and dumping rain in Lakewood. Our gutters are overflowing!

[Cloud]

It’s a tad snowy at BFI! 

[TT-SEA]

What a fun morning... about as dynamic as it gets with that low passing right over Seattle.     We went from the house shaking in the wind and rain pounding against the windows and the power out to gentle, calm snow falling in about an hour.

[Perturbed Member]

2 minutes ago, Deweydog said:

Definitely. Things could start very similar to 12/18/05 where areas just south of the river saw some decent accumulations with the initial warm frontogenesis. I’m sitting at ground zero for the downslope. Looks like Larch should be gusting 50+ for at least 24 hours starting tomorrow afternoon.

That airmass was much warmer than this one right?

How well did the metro area do as a whole?

Being on the far western end of the metro I think I should be safe from that downsloping but the outflow of cold air will also be shallower. Sometimes these far west areas especially around Forest Grove and Banks do pretty well from damming up a bunch of cold air against the coast range but not sure that will be deep enough to matter here. 

[TacomaWx]

8 minutes ago, SouthHillFrosty said:

Rain/snow mix here and 33. I doubt we might be able to get any accumulation with the amount of water everywhere 

It accumulated up north just fine with heavy rain earlier. 

[RentonHill]

4 minutes ago, TT-SEA said:

Definitely appears that way now... it will be interesting to see what happens to temps in the Seattle area this afternoon when the precip is gone.  

[Mid Valley Duck]

Euro is best case scenario for the Willamette Valley. But I think its scouring out the valley and metro too quickly.

[Doinko]

Just now, BLI snowman said:

Yeah, there was a definite E-W divide with that one due to the dry air advection off the foothills. Had a windswept 1/4" in Brush Prairie but areas to the south and to the west of I-5 generally had 1+" and Scappoose had 2-3".

 

I'm in the west metro, but do you think the wind could reduce our snow chances initially? The WRF-GFS is showing 55mph+ gusts accelerating down the west hills, but much lighter wind just a few miles S/W.

[Deweydog]

So bizarre the NWS going with lows 10-15 tomorrow night in the advection. It’s like they don’t realize how incredibly rare that would be.

[lowlandsnow]

What does radarscope show for the central sound anymore snow coming?