December 2016 Observations and Model Discussion for the Pacific Northwest

[Weather101]

It's over.

At least we got January

[MossMan]

Wasn't exactly an inspiring write up in the snow dept.,

Felton always runs very conservative when it comes to snow...which I guess is smart...but doesn't inspire us weenies though.

[Gradient Keeper]

I'm here! sorta

 

Through HR 42 block stronger than previous runs, offshore ridge weaker. Hope this run handles those cut-off lows northwest of Hawaii differently.

[Gradient Keeper]

Day 2

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120112/048/500h_anom.na.png

[luvssnow_spokane]

I noticed the Heat Island Effect for SeaTac has a much greater effect on the lower the temps hence why lows are affected more than highs typically.

This morning SeaTac shows 42 for the low and although I don't have a temp sensor the small puddles this morning had ice on top and ice on the car to the point I had to pour water over the door to open it. Big difference over such a short distance within the city of Seattle.

Where do you live? I live out in BonneyLake and I was not even close to freezing with a low of 41...

[Gradient Keeper]

Not liking the kona low

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016120112/gfs_z500_mslp_npac_9.png

[ShawniganLake]

29.6F here this morning.  Starting off December with the coldest morning of the season. 

[jcmcgaffey]

Where do you live? I live out in BonneyLake and I was not even close to freezing with a low of 41...

Ballard/Greenwood area only about 3-4 miles north of downtown Seattle.

 

I am in a bit of small valley between two small hills about 250ft above sea level so that might help keep the cold in.

 

It was clear last night and early morning as well before the sun came up.

 

Edit: I see a couple stations near me on the wundermap show some places got down to 34-35 last night so must be a small microclimate thing.

[Timmy]

Sundays system is looking a little colder with more cold air coming off Alaska than previous few runs

[Gradient Keeper]

Day 3

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120112/072/500h_anom.na.png

[Gradient Keeper]

Yuck .

HR 84

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016120112/gfs_z500_mslp_npac_15.png

[Deweydog]

Horrific.

 

Someone go get the keys to the vomitorium.

[Phil]

Eh, 12z GFS looks to be following 06z's lead with the westward trend of the initial anticyclonic breaker, hence a more progressive downstream solution..

[Timmy]

This is pretty bad actually out 84 hours.

[Gradient Keeper]

Day 4

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120112/096/500h_anom.na.png

[crf450ish]

[SilverFallsAndrew]

Well fellas we tried. Maybe January. I might get an inch or two of snow Monday morning if I'm lucky

[Gradient Keeper]

Onto the EURO....and GEM. I will say I hate seeing this consistent trend now with the GFS and hoping we don't see this on other runs or Ensembles warming any before day 10. We still get chilly, but doesn't look promising for snow if this solution wins out.

[Gradient Keeper]

Day 5 is different. We have a full merge with Alaskan and Aleutian block

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120112/120/500h_anom.na.png

[Deweydog]

Complex pattern.

[Phil]

Day 5 is different. We have a full merge with Alaskan and Aleutian block

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120112/120/500h_anom.na.png

Look at that small ULL vort over the Aleutians, right underneath the block. That vort will try to phase with the kona low and ignite further offshore vorticity..

[Timmy]

Complex pattern.

Hot take

[catnip]

BC is colder so far on this run.

[Gradient Keeper]

The life of a weather geek and model rider. The trials and tribulations. Ups and downs. Highs and lows. Exuberance and anguish.

[Gradient Keeper]

Complex pattern.

Extremely

[crf450ish]

Pics for the less fortunate?

http://i.imgur.com/DSP0YEj.jpg

 

http://i.imgur.com/wCEAdz2.jpg

 

http://i.imgur.com/FAPYNkS.jpg

 

Taken the same day you asked if I had pics. I originally said no, but then ended up making a run into Reardan for some stuff. Reardan actually did pretty well. About 3" fell there. Was 27 degrees when I drove through, freezing fog wrapped the trees making everything look that much cooler. 

[MR.SNOWMIZER]

Looks ok

[bainbridgekid]

Well it took till December, but I finally got my first frost this morning.

 

Mostly on the roofs and the open spots of grass, but it was nice to see some white on the ground for the first time in probably ~8 months.

[VancouverIslandSouth]

First frost of the season here in Victoria, below freezing in low lying areas and all the roof tops are covered. This event is going to be a quick hitter no doubt; the models aren't looking as good for the transition in, but the overrunning event has looked nice on the more recent runs. Hopefully the outflow will kick in a bit earlier, it was pushed back to late Monday on the 6z.

[Gradient Keeper]

Supposedly GFS wants to give PDX 2-4" of snow..... Not believing it. Westerly 850mb flow is not good for snow.

[ShawniganLake]

BC is colder so far on this run.

No big changes up here.  Still looks like a big overrunning snowfall.  The Monday snow is a question mark IMO.  Might have to wait for the outflow before everyone is cold enough for sticking snow, and timing that is tough.  A showery airmass with 925mb temps of -1C and a south wind sounds like 35F mixed precip to me. 

[chopper 918]

All eyes on the ECMWF.  

[catnip]

No big changes up here.  Still looks like a big overrunning snowfall.  The Monday snow is a question mark IMO.  Might have to wait for the outflow before everyone is cold enough for sticking snow, and timing that is tough.  A showery airmass with 925mb temps of -1C and a south wind sounds like 35F mixed precip to me. 

 

Sorry, should have specified. I was referring more to north/central.

 

It would be nice to get something on Monday, at least it will stick around for a day or two.

[stuffradio]

No big changes up here.  Still looks like a big overrunning snowfall.  The Monday snow is a question mark IMO.  Might have to wait for the outflow before everyone is cold enough for sticking snow, and timing that is tough.  A showery airmass with 925mb temps of -1C and a south wind sounds like 35F mixed precip to me. 

Our biggest snows of the year come from overrunning events, unfortunately. Remember the ice bombs on the Golden Ears bridge? That was crazy. The ice was damaging the cars windows.

[Deweydog]

Bring November back.

 

Mild temperatures, better model runs.

[Gradient Keeper]

12z GEM day 3. No Kona Low YET

 

http://maps3.pivotalweather.com/maps/models/ggem/2016120112/072/500h_anom.na.png

[luminen]

Nice morning on Grouse Mountain today:

http://i.imgur.com/XeJPxna.png

[Gradient Keeper]

Hr 84

 

http://maps3.pivotalweather.com/maps/models/ggem/2016120112/084/500h_anom.na.png

[catnip]

Our biggest snows of the year come from overrunning events, unfortunately. Remember the ice bombs on the Golden Ears bridge? That was crazy. The ice was damaging the cars windows.

 

Have they had a chance to test the new system they installed to prevent that? I don't think we have had much snow since that episode.

[Gradient Keeper]

HR 90 - Looks much better than the GFS so far

 

http://maps3.pivotalweather.com/maps/models/ggem/2016120112/090/500h_anom.na.png