December 2020 Weather Observations for the PNW

[Deweydog]

Seems like skiers over Xmas break might be happy, assuming any AR potential doesn’t prove too destructive.

[Fircrest]

5 minutes ago, jakerepp said:

Heck I’d probably take that. Just buy something ahead of time and wait for the engine to be replaced and eventually sell it. 

The dealership was Larson in Tacoma.  BTW I like Carcomplaints.com, it is a good site to get an idea about which cars/models to avoid.

[TT-SEA]

Partly sunny and 52 in NB... east wind is gone for now.  

[MossMan]

4 minutes ago, TT-SEA said:

Partly sunny and 52 in NB... east wind is gone for now.  

Still a goofest up here. 

[Phil]

5 minutes ago, TT-SEA said:

Partly sunny and 52 in NB... east wind is gone for now.  

Let me guess..your house is under that cloud?

[snow_wizard]

Major improvement on the EPS for the period just before Christmas.  The control gets quite interesting in fact.  That makes all of the big 3 better on this run. 

[TT-SEA]

5 minutes ago, Phil said:

Let me guess..your house is under that cloud?

That is Mt Si... elevation 4,167 feet.    Its not a populated up there as Stampede Pass.  

[snow_wizard]

Pretty interesting to note that while the 12z EPS takes the PNA a bit lower than previous runs the real change is a considerably more negative NAO than previous runs.  The -PNA -NAO combo is usually a good outcome for us.

[TigerWoodsLibido]

3 minutes ago, snow_wizard said:

Pretty interesting to note that while the 12z EPS takes the PNA a bit lower than previous runs the real change is a considerably more negative NAO than previous runs.  The -PNA -NAO combo is usually a good outcome for us.

Looks pretty neutral to me. Let's try not to wishcast too much.

[snow_wizard]

8 minutes ago, TigerWoodsLibido said:

Looks pretty neutral to me. Let's try not to wishcast too much.

I was specifically pointing to the EPS which is -1.  You're entitled to your opinion though.  We all know you think nothing good will ever happen anyway.

What I said is correct.  The EPS was slightly lower on the PNA and quite a bit lower on the NAO than previous runs.  Keep in mind to get the average to -1 or so there are a lot of members that are lower.

[SilverFallsAndrew]

Up to 49 under partly sunny skies. 

[SilverFallsAndrew]

I'm with you Jim I think the future is bright. Might be to much maritime influence for much of the lowlands, prior to Christmas at least. I have a feeling there will be a Whatcom county event in the 18-25th timeline. 

[MossMan]

8 minutes ago, SilverFallsAndrew said:

I'm with you Jim I think the future is bright. Might be to much maritime influence for much of the lowlands, prior to Christmas at least. I have a feeling there will be a Whatcom county event in the 18-25th timeline. 

Let’s make that an extreme north Snohomish Co and north event! 

[Weather1011]

21 minutes ago, snow_wizard said:

I was specifically pointing to the EPS which is -1.  You're entitled to your opinion though.  We all know you think nothing good will ever happen anyway.

What I said is correct.  The EPS was slightly lower on the PNA and quite a bit lower on the NAO than previous runs.  Keep in mind to get the average to -1 or so there are a lot of members that are lower.

I don't think he meant that in a bad way he's just reporting what he is seeing....

[SilverFallsAndrew]

There is a legitimate chance we end up with above normal December precip, despite a very dry first half of the month. 

[SilverFallsAndrew]

PDX hanging on to the offshore flow and still 44. Mid 50s down the valley. 

[TigerWoodsLibido]

44 minutes ago, snow_wizard said:

I was specifically pointing to the EPS which is -1.  You're entitled to your opinion though.  We all know you think nothing good will ever happen anyway.

What I said is correct.  The EPS was slightly lower on the PNA and quite a bit lower on the NAO than previous runs.  Keep in mind to get the average to -1 or so there are a lot of members that are lower.

Just being a realist about our climate and reporting what the graphs show. I still think good things will eventually happen. They’re just not being depicted by the models other than some mountain snow.

[Deweydog]

11 years ago it was pretty chilly but NOT snowy.

[SilverFallsAndrew]

3 minutes ago, Deweydog said:

11 years ago it was pretty chilly but NOT snowy.

That was a classic, but underrated arctic outbreak. Given the fact it had no snow made it seem a bit underwhelming compared to the previous year. Was actually out in Oklahoma that winter, was one of their best ever. 

[Brian_in_Leavenworth]

2 minutes ago, hawkstwelve said:

Might have been shared already but also some good differences on the latest GEFS Extended vs. it's previous run.

Overall, some encouraging trends from the LR guidance models across the board.

 

Good trends on the ensembles.  Wondering if Ventrices IBM model was ran with the 0Z data.  If so, maybe it will be wrong.  I did have a couple of GIFs to compare last nights runs to the 12Z runs for the GEFS and the Canadian ensembles.

 

[Gradient Keeper]

Great trends on 12z runs/ensembles. Reminds me of 2008. Timing may move ahead for this pattern change too.

[MossMan]

15 minutes ago, Deweydog said:

11 years ago it was pretty chilly but NOT snowy.

I don’t have pics on my phone that far back...Please keep it to 2012-2020 please. 

[bainbridgekid]

33 minutes ago, Deweydog said:

11 years ago it was pretty chilly but NOT snowy.

Hood Canal froze over in spots with that one. Pretty rare to have saltwater freeze around here but the low dew points and lack of snow gave it excellent lake freezing capability.

[SilverFallsAndrew]

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. 

[GHweatherChris]

We don't need any more wasted cold, you can't have a stat ball fight.

[Jesse]

1 minute ago, GHweatherChris said:

We don't need any more wasted cold, you can't have a stat ball fight.

I’ll be creating a petition shortly. You can be my first signature!

[GHweatherChris]

2 minutes ago, Jesse said:

I’ll be creating a petition shortly. You can be my first signature!

Your down vote kinda makes a petition moot.

[SilverFallsAndrew]

Olympia had 3 consecutive lows of 6 with the December 2009 event. Pretty nice lows for no snow cover. Given highs most places were in the 30-32 range on the coldest days, it didn't have quite the bite (CAA) of say a December 1998, but had enough of a continental component to achieve some really nice radiational cooling. 

[Jesse]

Really pleased with how today has played it so far. Low overcast with a high of just 45 here, 44 at PDX.

Hopefully the system moving through is weak enough where the southerlies never quite make it up here and we stay in light gorge influence.

[Gradient Keeper]

Hmmm....

[TT-SEA]

Lots of mid 50s around the Seattle area with breaks of sun at times... decent day.    

[El_Nina]

No additional rain out of the drizzle this morning. It has dried out and is now overcast and 48.

[FroYoBro]

Next weekend looks pretty wet. 

[Gradient Keeper]

10 minutes ago, Jesse said:

Really pleased with how today has played it so far. Low overcast with a high of just 45 here, 44 at PDX.

Hopefully the system moving through is weak enough where the southerlies never quite make it up here and we stay in light gorge influence.

Likewise. Good news on that front.

2 PM
PDX-EUG: +1.5mb (Northerly flow)

PDX-SLE: +1.7mb (Northerly flow)

12z WRF shows easterly ingredients increasing around 3-5 PM.

[SilverFallsAndrew]

Next weekend is looking really wet. 

[Omegaraptor]

Really hoping the snow level stays below 5000’ next Saturday.

[Deweydog]

Weekend.  Wet.

[Gradient Keeper]

Look to me like a 8-10 day period of zonal onshore flow perhaps northwesterly flow before heights rise upstream with blocking setting up. Book it. MBG!

[ShawniganLake]

3 hours ago, snow_wizard said:

Doesn't really line up with the model runs we've been seeing.  We shall see.

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. 

[Deweydog]

I remember very little about the 2009 cold snap.