December 2020 Weather Observations for the PNW

[MossMan]

2 minutes ago, Deweydog said:

I remember very little about the 2009 cold snap.  

We did have a 9 degree low if I remember correctly...But other than that it was a boring chilly stretch. 

[BLI snowman]

8 minutes ago, Deweydog said:

I remember very little about the 2009 cold snap.  

Portland NWS had an oft overlooked WSW bust with the overrunning storm on the 13th (?). Forecasted 3-8" of snow even though all the models were keeping precip south of Salem. It didn't work out, which may have led into their reluctance to pull the trigger on anything a few weeks later when they busted the other way.

[Deweydog]

1 minute ago, BLI snowman said:

Portland NWS had an oft overlooked WSW bust with the overrunning storm on the 13th (?). Forecasted 3-8" of snow even though all the models were keeping precip south of Salem. It didn't work out, which may have led into their reluctance to pull the trigger on anything a few weeks later when they busted the other way.

I do remember that, although we did score some 35 degree drizzle that Saturday.  

[Deweydog]

***SLIGHTLY*** warmer over AK in the long range compared to yesterday’s 18z.

[jakerepp]

28 minutes ago, Deweydog said:

I remember very little about the 2009 cold snap.  

Lack of snow will do that.

i don’t remember it at all either, but I obviously remember 2008 very well.

[ShawniganLake]

Partly sunny and 55 at the Christmas tree farm earlier this afternoon.  Warmest day since early November. 

[Deweydog]

2 minutes ago, ShawniganLake said:

Partly sunny and 55 at the Christmas tree farm earlier this afternoon.  Warmest day since early November. 

Looks like you need a gorge too!

[Meatyorologist]

Move ahead that SSW by a few weeks...?

We would be feeling the effects of this by Christmas.

[Weather1011]

52F today for a high 

[Weather1011]

I don't know how Seahawks allowed the Giants to do this. Lol 

[TigerWoodsLibido]

1 minute ago, Weather1011 said:

I don't know how Seahawks allowed the Giants to do this. Lol 

We're ranting about it in the banter thread.

[Phil]

2 hours ago, hawkstwelve said:

Lots of pretty things to look at in this frame on the CFS control, but I particularly enjoy that the East Coasters are roasting under a strong ridge. That's a thing of beauty.

Why would you root for my suffering? Am I really that bad of a person? #sadist

[Meatyorologist]

Some support from the GFS...

[Phil]

1 hour ago, ShawniganLake said:

Yea. I don’t disagree. Feels like we are more likely to be heading for a chilly active stretch of weather in the pre Christmas period.  Doesn’t look like the EPO is going to cooperate but as you mentioned some -NAO in combo with -pna could work. 

It usually does work if they’re negative at the same time. In extreme cases you get a 1968/69 or 1942/43 outcome when they combine like that.

In terms of p-value negative departures are actually more consistent @ SeaTac with -PNA and -NAO together versus -EPO alone. Which I found interesting.

[Gradient Keeper]

I would say there is growing confidence that we are soon to see a major pattern change emerging for AK block. Yup.

00z GFS in 3 hours 19 minutes

[TigerWoodsLibido]

Hopefully tonight the models perform better than the Hawks. Gonna be some pissed-off posters in here for a while. But some goodies on the models would sure "soften the blow."

[fubario]

19 minutes ago, Weather1011 said:

I don't know how Seahawks allowed the Giants to do this. Lol 

underestimate any nfl team.. get poor outcomes

[luminen]

2 hours ago, SilverFallsAndrew said:

Looking back at the December 2009 arctic blast, I would definitely take a repeat. Here are the temps from the 6-11th. 

PDX:

39/28

31/23

32/14

30/12

34/13

34/14

SLE:

38/25

32/18

33/14

31/10

33/10

35/12

EUG:

37/22

32/16

30/10

30/7

32/8

32/11

 

For PDX and SLE it was fairly similar to the temps put up with the December 2013 event. 

I remember going up to Council Crest with my dad during this blast. It was a chilly 17 degrees with what seemed like a decent amount of snow. Where we lived the coldest temp registered was 8 degrees and it was even snowing! Great memories! 

[snow_wizard]

10 minutes ago, DJ Droppin said:

I would say there is growing confidence that we are soon to see a major pattern change emerging for AK block. Yup.

00z GFS in 3 hours 19 minutes

You can just feel it.  The models keep almost getting there, and they probably will before too long.

[TigerWoodsLibido]

1 minute ago, snow_wizard said:

You can just feel it.  The models keep almost getting there, and they probably will before too long.

I hope you're right man. I really do.

[Brian_in_Leavenworth]

GEFS looks like the 0Z from last night. 

[Meatyorologist]

GEFS was weird. Onto the 12z, weenies.

[GHweatherChris]

31 minutes ago, Phil said:

Why would you root for my suffering? Am I really that bad of a person? #sadist

Yes

[Omegaraptor]

48 minutes ago, Meatyorologist said:

Move ahead that SSW by a few weeks...?

We would be feeling the effects of this by Christmas.

Siberian event too. For the PNW in a Niña year a Siberian SSW is superior to a North Atlantic SSW.

[Deweydog]

Also........ It snowed nicely 26 years ago today.  My first legit Portland area snowfall.

[Gradient Keeper]

32 minutes ago, snow_wizard said:

You can just feel it.  The models keep almost getting there, and they probably will before too long.

Yeah I really can. I can sense it, I can feel it, and I can envision the pattern change. Model runs are soon to become quite fun, promising, and cold!

00z GFS in 2 hours 34 minutes

00z ECMWF in 4 hours 49 minutes

[luminen]

11 minutes ago, Deweydog said:

Also........ It snowed nicely 26 years ago today.  My first legit Portland area snowfall.

How much did you get? 

[Gradient Keeper]

East wind is redeveloping here and it is very cold.

[snow_wizard]

I was just looking at the last 4 GFS runs for the strat warming event and the 18z was much more massive for both area and intensity of the warming.  The difference was huge.  We'll have to see how it plays out.

[FroYoBro]

2 minutes ago, DJ Droppin said:

East wind is redeveloping here and it is very cold.

I’m not sure 44 at pdx counts as very cold in December. 

[snow_wizard]

15 minutes ago, Deweydog said:

Also........ It snowed nicely 26 years ago today.  My first legit Portland area snowfall.

I do seem to recall  a decent cold snap in early December 1994.  Don't think we had much snow here though.

[snow_wizard]

1 minute ago, FroYoBro said:

I’m not sure 44 at pdx counts as very cold in December. 

It's colder where he is.

[Gradient Keeper]

2 minutes ago, FroYoBro said:

I’m not sure 44 at pdx counts as very cold in December. 

41.8 here. Not the temp of course not, the wind is however very cold even as light as it is, for now.

00z EPS (Pivotal) in 7 hours 26 minutes

[snow_wizard]

8 minutes ago, DJ Droppin said:

East wind is redeveloping here and it is very cold.

You guys are about the only place that has been at all chilly this weekend other than yesterday morning in some places.  Really lame here right now, but maybe it will clear out and get cold tonight.

[Gradient Keeper]

4 minutes ago, snow_wizard said:

You guys are about the only place that has been at all chilly this weekend other than yesterday morning in some places.  Really lame here right now, but maybe it will clear out and get cold tonight.

It may be slow clearing for many locations as high pressure is reasserting itself with light gradients outside of the Gorge or easterly gaps.

 

925mb temps show the Columbia Basin/eastern Washington cold pool is deepening. I'd look for this to expand a bit further to the west and southwest perhaps down to Hermiston-Arlington. The 0c contour might make it to The Dalles. This will help fuel another round of gusty cold east winds.

[weatherwonder]

18 minutes ago, DJ Droppin said:

Yeah I really can. I can sense it, I can feel it, and I can envision the pattern change. Model runs are soon to become quite fun, promising, and cold!

00z GFS in 2 hours 34 minutes

00z ECMWF in 4 hours 49 minutes

Winter is coming!

0z tonight shall show nice changes!

[Dave]

3 hours ago, SilverFallsAndrew said:

Looking back at the December 2009 arctic blast, I would definitely take a repeat. Here are the temps from the 6-11th. 

PDX:

39/28

31/23

32/14

30/12

34/13

34/14

SLE:

38/25

32/18

33/14

31/10

33/10

35/12

EUG:

37/22

32/16

30/10

30/7

32/8

32/11

 

For PDX and SLE it was fairly similar to the temps put up with the December 2013 event. 

Hmmm. 4 straight lows under 12, yet there was exactly zero snow on the ground. Clearly, this climate can no longer support such anomalies. BTW, ice hockey was being played on some ponds in west Eugene during that event. 

[SilverFallsAndrew]

10 minutes ago, dolt said:

Hmmm. 4 straight lows under 12, yet there was exactly zero snow on the ground. Clearly, this climate can no longer support such anomalies. BTW, ice hockey was being played on some ponds in west Eugene during that event. 

Until January 2021 shatters everything we thought we knew about this climate!

[TigerWoodsLibido]

13 minutes ago, dolt said:

Hmmm. 4 straight lows under 12, yet there was exactly zero snow on the ground. Clearly, this climate can no longer support such anomalies. BTW, ice hockey was being played on some ponds in west Eugene during that event. 

If only I'd lived in Eugene in 2009...

[Deweydog]

46 minutes ago, luminen said:

How much did you get? 

Couple inches maybe?