December 2016 Observations and Model Discussion for the Pacific Northwest

[SilverFallsAndrew]

Looking at the RPM it is showing nearly 4" of precip at my location in the next 72 hours. The Cascades are going to get totally buried.

[crf450ish]

Live pic from my backyard... 

 

Pretty blue spruce!

[Phil]

If you guys remember the 500mb setup in January of 2011, that was another scenario where the +NAO/Hudson Bay Vortex consolidated last minute and screwed up the refractive NAMT process that lead to the failure of what could have been a historic snow event.

 

It's no coincidence that the midwinter mediocrity in recent years has coincided with the prolonged +NAO stretch. Hard to know for certain why this pattern keeps resurfacing, but it's something that needs to be watched IMO..

[Winterdog]

2" here and light snow again.

2"!! I only got half and inch. I guess that's because I'm further east than you. I was fearing the models would erase our arctic air after seeing the Euro last night. Looks like it's not going to happen, after all it was still four days out and well within the clown range.

[snow_wizard]

The 4km WRF still hinting at some lowland snow Monday.

[dairyd]

It is colder now (26) than when the snow arrived (27) at midnight.  WRF and Seattle office has us at 35 by now lol.  Wind is still NE at 10-15.

[SilverFallsAndrew]

GEM looks to be in fair agreement with the GFS.

[snow_wizard]

2"!! I only got half and inch. I guess that's because I'm further east than you. I was fearing the models would erase our arctic air after seeing the Euro last night. Looks like it's not going to happen, after all it was still four days out and well within the clown range.

The Euro had Arctic air for us last night. Cold is not in doubt next week.

[snow_wizard]

Down to 30 here now. Wasn't expecting this.

[Timmy]

The battle of the east and west is in full swing! Just checked the cam temps on my hood. Govy camp is at 33f, and just a couple miles (maybe 2) east at snow bunny (same elevation) it's 24f.

[HighlandExperience]

The 4km WRF still hinting at some lowland snow Monday.

Let's hope. A broken clock is right at least once a day!!

[Phil]

GEM looks to be in fair agreement with the GFS.

It's even more hideous in the extended range, but similar problems with the consolidation of the +NAO/dampened NAMT hence the trend towards abstrong, fully coupled PV/+AO. Similar to the problems faced over the last two winters.

 

Far from certain it'll verify, though, and in the long run I'm betting against something like that persisting for very long.

[Geos]

Will post pics in a bit. Just a tad below freezing here with a mix of freezing rain and snow. But it's light. Roads are a mess in the area.

[Abbotsford_wx]

24.5F here with 2" so far.

[TT-SEA]

Pretty insane snowfall here right now.   

[MossMan]

So I'm a bit confused, are we still Arctic cold again starting Monday or not?! What happened to the arctic front that was going to sweep down Sunday night?? Are we just back to business as usual?

[TT-SEA]

Temp down to 23.5 here.   Amazing that its still dropping.

[luminen]

Big fluffy flakes falling now. Temp 32F...which is slightly warmer than YVR and Richmond.

[Phil]

So I'm a bit confused, are we still Arctic cold again starting Monday or not?! What happened to the arctic front that was going to sweep down Sunday night?? Are we just back to business as usual?

Model chaos..mostly due to differences in the handling of tropical convection and large scale wave driving. These factors determine the nature of the polar vortex, hence your Arctic potential.

[weatherfan2012]

You guys have absolutely no reason to be panicking. Overall you're set up fairly nicely in the long run, barring an unexpected consolidation of the PV/AO which looks unlikely. Hard to find any negatives for you guys, actually..maybe too much Indo-China forcing but that's yet to be determined and might not be a problem at all.

If anyone should be panicking it's me. This looks like a classic "suppression depression" winter here. A frigid, dry, mostly snowless piece of crap with the occasional warm blast.

the early to mid 80s were like that plus 08-09 saw something very much alike lot of cold but little if any fan fair snow to show for it it was it until March when we finally saw a decent snow event pretty lol that it took until March doing that year.

[snow_wizard]

Let's hope. A broken clock is right at least once a day!!

 

The 12z actually shows a band of heavy snow JUST south of us on Monday.  Maybe we will get lucky this time.

[snow_wizard]

So I'm a bit confused, are we still Arctic cold again starting Monday or not?! What happened to the arctic front that was going to sweep down Sunday night?? Are we just back to business as usual?

 

Cold is almost a given at this point.

[snow_wizard]

The 12z ensemble is still quite chilly for early next week. Still looks like two cold shots next week.

[MossMan]

Cold is almost a given at this point.

So we just need to worry about moisture then correct?

[SilverFallsAndrew]

A lot of potential for next week to trend colder down the stretch...I think we need to keep an eye on the 23rd-New Year's for something big.

[Winterdog]

The Euro had Arctic air for us last night. Cold is not in doubt next week.

I was looking forward to an incoming front Monday with a few inches of snow with it. The Euro took that away and looking at the 500 level GFS this morning I assumed the worst. You are right. Still cold next week and we still have a shot at some snow Monday afternoon according to the 12Z GFS. And a possible white Christmas out there in super clown range.

[snow_wizard]

the early to mid 80s were like that plus 08-09 saw something very much alike lot of cold but little if any fan fair snow to show for it it was it until March when we finally saw a decent snow event pretty lol that it took until March doing that year.

We had quite a bit of snow in 1984-85 and 1985-86. 1983-84 was the dry / cold one.

[snow_wizard]

So we just need to worry about moisture then correct?

Yup.

[crf450ish]

When is the final shot going to come?

[snow_wizard]

A lot of potential for next week to trend colder down the stretch...I think we need to keep an eye on the 23rd-New Year's for something big.

I totally agree. We have the right players...we just need them to come together right.

 

BTW there are some wildly cold ensemble members on this run.

[TT-SEA]

Good Lord... getting silly out there.

[Geos]

Pics

 

 

 

 

[MR.SNOWMIZER]

I was right about one thing, the showers rolling in even with onshore are still producing snow. It just starting snowing here again at work. My son called from home and said it was snowing hard and temp went back down to 31.

[jcmcgaffey]

Speaking of weather apps.

 

Mine is still showing snow on Monday, Thursday, and Friday next week with 1-3" on each day.

 

https://www.wunderground.com/cgi-bin/findweather/getForecast?query=47.68789291,-122.37007141&sp=KWASEATT403

[Phil]

the early to mid 80s were like that plus 08-09 saw something very much alike lot of cold but little if any fan fair snow to show for it it was it until March when we finally saw a decent snow event pretty lol that it took until March doing that year.

Yeah, 08/09 was an old-school niña. That anticyclonic amplification into the upper strat, right out of the NPAC, is something that just doesn't happen very often anymore. Truly an epic destruction of the entire PV that winter from 1mb down to the surface.

 

And yeah, I remember that crazy blizzard in March. Kind of a two part system though, with the first wave crapping out half melted mashed potatoes, followed by the beastly ULL out of planet Hoth throwing down 10" of powder in 2hrs.

[Geos]

I'm at work in Bellevue but my wife just called and said it's snowing very heavy at my house, with very thick flakes and adding up fairly fast.

 

Kind of surprised to hear that because it was a rain/snow/sleet mix when I left - must be the heavy precip rates.

 

Yep, some heavy returns are doing the trick.

 

 

Still getting a mix here.

[TT-SEA]

Yep, some heavy returns are doing the trick.

 

http://climate.cod.edu/data/nexrad/ATX/N0Q/ATX.N0Q.20161209.1757.gif

 

Still getting a mix here.

 

 

Heavy snow is an understatement here.  

[weatherfan2012]

We had quite a bit of snow in 1984-85 and 1985-86. 1983-84 was the dry / cold one.

I hope you guys get a good snowy winter this year you all deserve it after the last few years.

[snow_wizard]

Looks like an amazing cold pool builds up over the Basin late next week. That could really help us down the road. The gradient angle become such that my area could have a strong inversion together with the very cold air mass. Could come up with some crazy numbers...especially if there is snow on the ground.

[snow_wizard]

Temp still 30 degrees here with a slowly thickening layer of ice. One thing this area can get is ZR.