December 2020 Weather Observations for the PNW

[Winterdog]

12 minutes ago, MossMan said:

It’s interesting that in January 2019 on the forum there did not seem to be much of any talk about the SSW...Though I didn’t go back and look at the entire Jan 2019 thread. Seems to be all the rage on the December 2020 thread however. 

Yeah, I do remember some mention of a SSW in the past but never posited as  a huge precursor to us getting an arctic intrusion. Now it seems like the 500 and 850 level model runs are passé in comparison 

[snow_wizard]

25 minutes ago, Cloud said:

Obviously I'm pretty noobish with the SSW stuff. SSW is gonna happen! But for us, do we want the SPV to split or nah? 

Everyone wants it to split.  It's a potential win for much of the US.

[snow_wizard]

3 minutes ago, Acer said:

Yeah, I do remember some mention of a SSW in the past but never posited as  a huge precursor to us getting an arctic intrusion. Now it seems like the 500 and 850 level model runs are passé in comparison 

More people have seen the light on how big a deal it is.  It usually leads to big pattern changes.  In this case the models are beginning to show an MJO wave may enter the picture in a favorable phase for the NW as well.  Lots of reason for hope.

[snow_wizard]

The EPS continues to look chillier for week two than previous runs.  Last nights 0z was better than yesterdays 12z and now this run is better yet.  Nothing grand, but it shows decent negative height anoms over the NW.

[ShawniganLake]

22 minutes ago, MossMan said:

It’s interesting that in January 2019 on the forum there did not seem to be much of any talk about the SSW...Though I didn’t go back and look at the entire Jan 2019 thread. Seems to be all the rage on the December 2020 thread however. 

It’s definitely going to be the catch phrase of the 20-21 season. Whatever gives people hope. 

[ShawniganLake]

50 minutes ago, Brian_in_Leavenworth said:

In the 10-15 day period, the GFS builds a huge ridge over us.  GEFS had a weaker signal for that.  GFS V16, the new one that will take over soon, had ridging like the GFS, but a bit weaker, allowing for a bit of a progressive flow.  Also had a bit more ridging in the Gulf of Alaska.  The Canadian ensembles, as has been the cast for the last week or two, also has some ridging over us in that range. 

But the EPS disagrees.  Of course it is not the pattern that those of you west of the mountains want, but at least it is not an inversion pattern.  Actually a pattern that would bury my area in snow.   Looks like La Nina.  Here is the latest EPS:

 

 

 

Not really sure if a strong Aleutian low and massive warm anomalies across most of Canada would be considered a La Niña pattern. 

[TacomaWaWx]

4 minutes ago, ShawniganLake said:

It’s definitely going to be the catch phrase of the 20-21 season. Whatever gives people hope. 

Think it was low solar last year. 

[Brian_in_Leavenworth]

9 minutes ago, snow_wizard said:

More people have seen the light on how big a deal it is.  It usually leads to big pattern changes.  In this case the models are beginning to show an MJO wave may enter the picture in a favorable phase for the NW as well.  Lots of reason for hope.

Some of the MJO forecasts seem to want a wave to emerge in phase or zone 2, which is decent for us.  Doesn't seem to be a strong signal . . . yet.  

[snow_wizard]

1 hour ago, Brian_in_Leavenworth said:

Maybe he is talking about Oregon.  In Leavenworth, we have a white Christmas about 90% of the time.  And places north like Okanogan and Winthrop probably 90% or more.  But when you get south, like Walla Walla, Moses Lake, etc, it is less.

 

Here is a map of the historic probability of a white Christmas courtesy of the NWS in Spokane.  This covers Washington and most of Oregon.

Yeah...I was thinking of places like Cle Elum having snow nearly every year.  It appears some parts of South Central WA and North Central OR have a very low chance.  The north half of Central and Eastern WA is another climate zone entirely.

[snow_wizard]

7 minutes ago, ShawniganLake said:

Not really sure if a strong Aleutian low and massive warm anomalies across most of Canada would be considered a La Niña pattern. 

A lot of the period is actually more zonal.  The PNA spits out at a flat zero.  At any rate there will probably be big model changes coming soon.

[snow_wizard]

7 minutes ago, TacomaWaWx said:

Think it was low solar last year. 

We still have that too.  Just coming out of the deepest solar min in 200 years.  This stuff matters.  The SSW stuff has worked out well for us in recent years.  As I've said it reshuffles the pattern.

[snow_wizard]

7 minutes ago, Brian_in_Leavenworth said:

Some of the MJO forecasts seem to want a wave to emerge in phase or zone 2, which is decent for us.  Doesn't seem to be a strong signal . . . yet.  

Yeah...the models have been struggling to get a handle on the MJO.  That is going to be another biggy going forward.  Cold ENSO favors good regions for cold in the NW.

[snow_wizard]

17 minutes ago, ShawniganLake said:

It’s definitely going to be the catch phrase of the 20-21 season. Whatever gives people hope. 

This seems kind of flippant.  Some very respected mets put a lot of stock in it.

[Brian_in_Leavenworth]

18 minutes ago, ShawniganLake said:

Not really sure if a strong Aleutian low and massive warm anomalies across most of Canada would be considered a La Niña pattern. 

I  see your point.  though above normal precip and tons of mountain snow are very much Nina.  Bitter cold isn't there for sure, but Nina's are not wall to wall cold.   So maybe not 100% a nina pattern, but nothing at all like a nino pattern either.  Temps for us look to be seasonal.

[snow_wizard]

5 minutes ago, Brian_in_Leavenworth said:

I  see your point.  though above normal precip and tons of mountain snow are very much Nina.  Bitter cold isn't there for sure, but Nina's are not wall to wall cold.   So maybe not 100% a nina pattern, but nothing at all like a nino pattern either.  Temps for us look to be seasonal.

I think a rather interesting aspect of the pattern is the NAO will be tanked, but it won't be cold in the east in spite of not having a -PNA.  Kind of a curiosity.  Probably no sustainable for long.  Something will give.

[SilverFallsAndrew]

Seems like a tremendous amount of wishful thinking on here today. Fear not though, we will be alright. 

[SilverFallsAndrew]

11.63” of rain on the month now, could get up around 13” or so by the end of the month. December will end up a bit above average. 

[Deweydog]

Wouldn’t any weather pattern during a nina technically be considered a nina weather pattern?

[ShawniganLake]

16 minutes ago, snow_wizard said:

This seems kind of flippant.  Some very respected mets put a lot of stock in it.

Not sure about flippant. It’ll be a game changer for someone but not necessarily everyone is going to cash in. 

[snow_wizard]

4 minutes ago, SilverFallsAndrew said:

Seems like a tremendous amount of wishful thinking on here today. Fear not though, we will be alright. 

A lot of the people saying the favorable things for us are from the East Coast.  Just sayin.

[FroYoBro]

9 minutes ago, SilverFallsAndrew said:

Seems like a tremendous amount of wishful thinking on here today. Fear not though, we will be alright. 

GOOD point.

[Gradient Keeper]

12z EURO for the past 2-3 runs has gone full blown Nina. I don't mind. EPS looks quite similar. And now we wait until January 12th or so.... I remember when supposedly mid-December was when the big pattern change were to take place. Who knows.

18z GFS in 7 minutes

 

[Winterdog]

3 minutes ago, DJ Droppin said:

 I remember when supposedly mid-December was when the big pattern change were to take place. Who knows.

18z GFS in 7 minutes

 

Maybe the east coast people know.  Here's hoping 

[Gradient Keeper]

19 minutes ago, SilverFallsAndrew said:

11.63” of rain on the month now, could get up around 13” or so by the end of the month. December will end up a bit above average. 

Wetter than a poodle in a car wash.

[MossMan]

[TT-SEA]

1 minute ago, Acer said:

Maybe the east coast people know.  Here's hoping 

The East Coast mets are the biggest morons in the world usually... unless they predict something for the West and then they are geniuses!  

[The Swamp]

1 minute ago, Acer said:

Maybe the east coast people know.  Here's hoping 

they don't give two craps about the west

just look at Bastardi, could care less

they could care less if we get cold and snow, they just know the pattern doesn't look good for them

[Winterdog]

2 minutes ago, TT-SEA said:

The East Coast mets are the biggest morons in the world usually... unless they predict something for the West and then they are geniuses!  

Your talking to a 6'2" moron right now buddy

[SilverFallsAndrew]

3 minutes ago, TT-SEA said:

The East Coast mets are the biggest morons in the world usually... unless they predict something for the West and then they are geniuses!  

I don't think the fact they are from the East Coast means much of anything. 

[Winterdog]

4 minutes ago, puyallupjon said:

they don't give two craps about the west

just look at Bastardi, could care less

they could care less if we get cold and snow, they just know the pattern doesn't look good for them

Geeze I'm starting to think you guys think I was serious.

[SilverFallsAndrew]

8 minutes ago, DJ Droppin said:

Wetter than a poodle in a car wash.

A very wet month would be 15"+, a top tier wet month is over 20"+. Examples of that would January 2012, March 2012, and December 2015. 

[Deweydog]

1 hour ago, MossMan said:

It’s interesting that in January 2019 on the forum there did not seem to be much of any talk about the SSW...Though I didn’t go back and look at the entire Jan 2019 thread. Seems to be all the rage on the December 2020 thread however. 

2019 was already written off as a dud at that point, plus February 2019 hadn’t happened yet.  Since that happened and it’s fresh in everyone’s minds, it’s a short walk to thinking this is our ticket out of what will likely be a dud of a first half.

[MossMan]

3 minutes ago, Deweydog said:

2019 was already written off as a dud at that point, plus February 2019 hadn’t happened yet.  Since that happened and it’s fresh in everyone’s minds, it’s a short walk to thinking this is our ticket out of what will likely be a dud of a first half.

I was getting nervous about our snow chances around this time 25yrs ago. Good thing we had a double windstorm by now to divert our attention a bit. 24yrs ago today I was really enjoying life! 

[Gradient Keeper]

At least the "dud" the next two weeks looks like it may feature a solid Nina pattern with tons of mountain snows. Better than a ridge-fest, inversion-palooza dud. A dud is a dud, but not every dud is a dud. Something like that.

00z ECMWF (New Year's Eve) in 127 hours 58 minutes

[El_Nina]

Periods of clouds and sun down in Newport, about 50 degrees.

[SilverFallsAndrew]

6 minutes ago, Deweydog said:

2019 was already written off as a dud at that point, plus February 2019 hadn’t happened yet.  Since that happened and it’s fresh in everyone’s minds, it’s a short walk to thinking this is our ticket out of what will likely be a dud of a first half.

Unlike 2018-19 Nina climo says our "best days" are ahead, whatever that may be. My money is on some monster troughing in the February-April period before we default back to endless summer in May. 

[Deweydog]

5 minutes ago, MossMan said:

I was getting nervous about our snow chances around this time 25yrs ago. Good thing we had a double windstorm by now to divert our attention a bit. 24yrs ago today I was really enjoying life! 

We had a decent icing event in December 1995 just before the big windstorm.  Although that was progged a few days earlier as a major outbreak.  Marky Mark Nelsen was all in for a couple days.

[MossMan]

6 minutes ago, Deweydog said:

We had a decent icing event in December 1995 just before the big windstorm.  Although that was progged a few days earlier as a major outbreak.  Marky Mark Nelsen was all in for a couple days.

We had a snow up here similar to what we just had but I thought it was right after windstorm #2...It’s a little vague. I do remember showering in our camper since it had hot water since we didn’t in the house due to the power being out for 3 days. Remember having my soap and shampoo and walking to the camper in the snow. 

[SilverFallsAndrew]

1 minute ago, Deweydog said:

We had a decent icing event in December 1995 just before the big windstorm.  Although that was progged a few days earlier as a major outbreak.  Marky Mark Nelsen was all in for a couple days.

Early Mark Nelsen was a Jim level cold fiend. I remember the early December 1995 icing event. It was a decent glaze down in the mid-valley, so I would imagine it was even worse in the metro area, being closer to the gorge. On paper December 1995 was pretty blah, solidly above average temps. 

[Deweydog]

4 minutes ago, SilverFallsAndrew said:

Unlike 2018-19 Nina climo says our "best days" are ahead, whatever that may be. My money is on some monster troughing in the February-April period before we default back to endless summer in May. 

A solidly cool February still seems like a good bet, although I do ponder the symmetry of a 2019 SSW/ENSO doppelgänger payback.