December 2018 Weather in the Pacific Northwest

[Farmboy]

Going to be a COLD month.

On Baffin Island.

[Farmboy]

We had two VCR’s in the house so I would tape the two channels and watch the 3rd between 5:18 and 5:27pm and then compare between Renner, Pool, and Wappler.

I did weather reports for the class in 5th grade...

[TT-SEA]

41 here and 43 in Seattle... must still be cloudy. 

 

Although I noticed just now that I can see the snow on the top of Mt Si from the front window even though its still dark so the low clouds must have cleared out.   

[Phil]

Wow it was gnarly up there. Probable worst conditions I've seen up there in few years. Looks like 12 inches new and that's a big storm for that pass.

Dashcam footage?

[Phil]

[Phil]

Looking *deeply* into the pattern progression this month in the extratropics, there are actually striking similarities to December 2012.

 

It’s not an ideal low frequency analog (much stronger STJ this year w/ east-shifted IPWP), but the nature of the intraseasonal convective tendencies and upstream wavetrain are similar.

 

In the case of 2012/13, it culminated in a major SSW by New Years and a major climate shift across the Pacific.

[TT-SEA]

00Z EPS:

 

5-10 day period...

 

 

 

10-15 day period...

 

 

 

 

 

 

That last frame is the COMPLETE opposite of the usual complaint on this forum that the cold air is "just across the border".  

 

When is all of Canada warm at the same time?    And this has been a recurring theme recently.    I sense a huge pattern change during the week before Christmas.... just a feeling.  

[Phil]

But yeah, the +WPO is a wave activity flux machine. Even though -WPO is (initially) better for cold in the PNW and the USA overall, it’s also a pattern that shuts down poleward vertical heat/mass fluxes, tightens the vortex, and ultimately leads to a warm pattern across the region.

 

So if we’re moving into a temporary Aleutian Low/+WPO pattern during early/mid December, we might as well put it to use and have it go nuclear. Kill the vortex and then open the Arctic floodgates after New Years and hope it happens fast enough to beat the unfavorable cycle of intraseasonal forcing after 1/10.

 

Because 1/10 - 2/5 looks hideous west of the Rockies, barring a bizarre sequence of events that somehow precludes the midwinter cycle of warm pool forcing.

[El_Nina]

While I was headed west down from the mountain I encountered a heavy cell of snow just west of government camp. It was so heavy the roads were turning white down to silent rock(~2500'). I snapped this pic just up from there:

[El_Nina]

I tried posting that at 11 last night but the picture wouldn't upload. So for anyone wondering when the snow was falling it was about 10.

[Phil]

00Z EPS:

 

5-10 day period...

 

 

 

10-15 day period...

 

 

 

 

 

 

That last frame is the COMPLETE opposite of the usual complaint on this forum that the cold air is "just across the border".

 

When is all of Canada warm at the same time? And this has been a recurring theme recently. I sense a huge pattern change during the week before Christmas.... just a feeling.

It’s a pattern change, but it’s intraseasonal in nature, arising from the cycle of AAM transport/MJO. We actually have a decent pool of analogs for this type of pattern progression. The period from 12/15 to ~ 12/25 will have the classic Alaska vortex/+EPO and storminess across the west coast.

 

But starting around New Years, the wavetrain retrogrades/amplifies and cold air returns to the US once again. Exactly where/how it arises is debatable, but it’s coming back. At least for some parts of the continent.

 

This is, ironically, a more classic “by the books” pattern and is (hopefully) easier to predict. I think is a pretty clear cut case. We’ll see, though..

[Chewbacca Defense]

We had two VCR’s in the house so I would tape the two channels and watch the 3rd between 5:18 and 5:27pm and then compare between Renner, Pool, and Wappler.

 

For me it was Guy Sharp on WXIA channel 11 in Atlanta.  The other news stations sucked.  Of course it was more about thunderstorms and whatnot....with the occasional ice/snow storm to throw in.

 

 

When it came to tracking a major weather event, I was almost as bad as the Rainman was regarding Judge Wapner when it came to catching Guy Sharp's forecast, my mom even started calling me Guy Sharp.....she still brings that up every once in a while...LOL

[TT-SEA]

For me it was Guy Sharp on WXIA channel 11 in Atlanta.  The other news stations sucked.  Of course it was more about thunderstorms and whatnot....with the occasional ice/snow storm to throw in.

 

 

When it came to tracking a major weather event, I was almost as bad as the Rainman was regarding Judge Wapner when it came to catching Guy Sharp's forecast, my mom even started calling me Guy Sharp.....she still brings that up every once in a while...LOL

 

Had to look him up... here is his segment from 6/5/85.    Looks like it was hot in Atlanta and cold and wet up here that day.   

 

Those old radar images make me laugh.   

 

https://www.youtube.com/watch?v=K0GffNmIkkc

[SilverFallsAndrew]

Looking *deeply* into the pattern progression this month in the extratropics, there are actually striking similarities to December 2012.

 

It’s not an ideal low frequency analog (much stronger STJ this year w/ east-shifted IPWP), but the nature of the intraseasonal convective tendencies and upstream wavetrain are similar.

 

In the case of 2012/13, it culminated in a major SSW by New Years and a major climate shift across the Pacific.

 

Oh that is going to get everyone excited! 

[Phil]

Oh that is going to get everyone excited!

Early January was close to being great. The block was just slightly too far east.

 

This isn’t going to be a year like 2011/12 or 1996/97 with a consolidated northern jet and Arctic air sitting nearby for weeks on end, oozing south with every tiny nudge. Essentially zero chance for a pattern like that. Instead, this year, the highest potential for winter weather will coincide with jet retraction cycles and meridional wave amplification initiating upstream or over Eurasia.

[TigerWoodsLibido]

Oh that is going to get everyone excited!

I lived on the coast and remember nothing significant out there during that time, I’m assuming you were being sarcastic lol.

[SilverFallsAndrew]

More rain for SoCal.

 

[ShawniganLake]

00Z EPS:

 

5-10 day period...

 

 

 

10-15 day period...

 

 

 

 

 

 

That last frame is the COMPLETE opposite of the usual complaint on this forum that the cold air is "just across the border".

 

When is all of Canada warm at the same time? And this has been a recurring theme recently. I sense a huge pattern change during the week before Christmas.... just a feeling.

I think it’s pretty common for Canada to torch like that during a strong nino. Which I realize this is not one.

[TT-SEA]

I think it’s pretty common for Canada to torch like that during a strong nino. Which I realize this is not one.

I thought a typical Nino set up would be warm west and cold east... just strange to see warmth from coast to coast.

[Brian_in_Leavenworth]

I think it’s pretty common for Canada to torch like that during a strong nino. Which I realize this is not one.

It may "torch", but still cold enough for snow across much of Canada.  It looks like a zonal pattern to me, which is not bitterly cold, but up there would still be cold enough for snow.  Edmonton not forecast to be above freezing for the next 2 weeks.   Toronto and Montreal in the 30's for the next 14 days.  

[SilverFallsAndrew]

I lived on the coast and remember nothing significant out there during that time, I’m assuming you were being sarcastic lol.

 

I was though at the time it was the coldest January in 20 years, since beaten by 2017.

[Farmboy]

I think it’s pretty common for Canada to torch like that during a strong nino. Which I realize this is not one.

The Weather Channel seems to want to have everyone believe it is a strong El Nino.. They're advertising a "much above normal" temperature regime for Washington for December...

[Jesse]

I thought a typical Nino set up would be warm west and cold east... just strange to see warmth from coast to coast.

Warm northern tier “cold” southern tier.

[ShawniganLake]

I thought a typical Nino set up would be warm west and cold east... just strange to see warmth from coast to coast.

[TT-SEA]

It may "torch", but still cold enough for snow across much of Canada. It looks like a zonal pattern to me, which is not bitterly cold, but up there would still be cold enough for snow. Edmonton not forecast to be above freezing for the next 2 weeks. Toronto and Montreal in the 30's for the next 14 days.

That map is for the 10-15 day period... it's not nearly that warm for the first 10 days.

[SilverFallsAndrew]

12z = ZZZZZZZZzzzzzzzzzzzzzzzzzzzzzz

[ShawniganLake]

12z = ZZZZZZZZzzzzzzzzzzzzzzzzzzzzzz

Splittyyyyyyyyyy

[jcmcgaffey]

41 here and 43 in Seattle... must still be cloudy.

 

Although I noticed just now that I can see the snow on the top of Mt Si from the front window even though its still dark so the low clouds must have cleared out.

There has been a little convergence coming from the east this time. It has been over Seattle area since Friday. It fades then strengthens. Had almost an inch of rain since yesterday morning. Almost 1/2” just this morning.

[TT-SEA]

There has been a little convergence coming from the east this time. It has been over Seattle area since Friday. It fades then strengthens. Had almost an inch of rain since yesterday morning. Almost 1/2” just this morning.

 

Wow!   I saw that on radar but had no idea it was producing that much rain.    

 

Only .05 here since yesterday and its been totally dry since early yesterday afternoon.  

[MR.SNOWMIZER]

Dashcam footage?

I was only going about 15mph.

[jcmcgaffey]

Wow! I saw that on radar but had no idea it was producing that much rain.

 

Only .05 here since yesterday and its been totally dry since early yesterday afternoon.

. Was at a holiday party last night in SODO and was absolutely dumping on the way home. It also woke me up around 3am or so cause it was raining so hard.

[MR.SNOWMIZER]

Wow!   I saw that on radar but had no idea it was producing that much rain.    

 

Only .05 here since yesterday and its been totally dry since early yesterday afternoon.

 

Must of been some pretty strong dynamics going on at blewett lastnight although there was not much on radar.

[MR.SNOWMIZER]

I was only going about 15mph.

Notice how far i kept traffic in front of me. There was a string of about 40 cars that were 10 feet apart.

[Phil]

I thought a typical Nino set up would be warm west and cold east... just strange to see warmth from coast to coast.

Not really.

 

The canonical niño pattern is GOA vortex, blast furnace across western/central Canada and the northwestern half of the US, and a chilly STJ/ULL pattern in the Deep South and Southeast.

[Phil]

The canonical niño pattern is GOA vortex, blast furnace across western/central Canada and the northwestern half of the US, and a chilly STJ/ULL pattern in the Deep South and Southeast.

Canonical niña is essentially the opposite..GOA ridge, cold air across most of western/central Canada and the northwest half of the US, and warm/dry anticyclones across the Deep South and Southeast.

 

The upcoming pattern is very niño-like. More so than any pattern we’ve seen since 2015/16.

[MossMan]

Notice how far i kept traffic in front of me. There was a string of about 40 cars that were 10 feet apart.

Speed and following too close in those conditions is the cause of most accidents in those conditions.

[Phil]

The “ridge west/trough east” pattern is not associated with any particular ENSO phase.

 

That’s actually a +TNH pattern, which is associated with warm pool forcing (which can exist as a low pass signal in both +ENSO and -ENSO, depending on their structure).

[Bryant]

I thought a typical Nino set up would be warm west and cold east... just strange to see warmth from coast to coast.

I'm surprised to see you say this. Figured it would be common knowledge for you

[MossMan]

Cloudy and 42 currently.

[TT-SEA]

I'm surprised to see you say this. Figured it would be common knowledge for you

 

 

I am far from an ENSO expert... never said otherwise.

 

I guess I was thinking about how they say a Nino favors the Midwest and East for snowstorms.   Phil talks about that all the time.