December 2015 in the Pacific Northwest

[stuffradio]

Last month of the year. Everyone party like it's 2015!

 

My New Year's resolution is to have a climate that gets us snowy winters, variable Spring where rain systems don't drizzle for days on end, and warm hot Summers, then crisp Falls with some storms in it.

[MossMan]

Snow by the 3rd week of December lasting into Christmas...you heard it here first!

[snow_wizard]

I think lowland snow will be a threat somewhere between Dec 10 and New Years.  Things look to be coming together for an interesting month. 

 

It's pretty hard to believe this month could average 4 degrees lower than last December and still not be below normal.  At this point I'm in for this one to run a good 3 to 5 lower than last December.  Better than that is certainly possible.

[Weather101]

Snow by the 3rd week of December lasting into Christmas...you heard it here first!

Well then! No need to look at the models !!

[Jesse]

Well then! No need to look at the models !!

God knows he isn't!

[Deweydog]

Best chance for a white Xmas in years.

[snow_wizard]

The ECMWF looks good for days 9 and 10.  Cool zonal flow giving way to a colder NW flow.  We're in business guys!

[snow_wizard]

Best chance for a white Xmas in years.

 

Ironically the chances look above average right now.  A long way to go, but the pattern appears to evolve favorably over the next two weeks.

[snow_wizard]

One thing for sure...the GFS and ECMWF agree we are going to get blasted by a strong consolidated jet around day 8.  This is what we want to see.

[Deweydog]

One thing for sure...the GFS and ECMWF agree we are going to get blasted by a strong consolidated jet around day 8. This is what we want to see.

One thing is even more sure. Your peaks get peakier and your valleys valleyier every year. Roll with it and go balls deep! Six foot drifts and windchill warnings! Let's do it!!!

[BLI snowman]

Best chance for a white Xmas in years.

 

I'm thinking Christmas could be a 2008/1980 hybrid.

[Weather101]

I'm thinking Christmas could be a 2008/1980 hybrid.

Let's not get too carried away yet.

[Bryant]

If you're one to believe that East Asia patterns are reflected in the US later down the road via the wave train, then it's worth mentioning that there's support for the colder anomalies in the west around day 9/10. 7-10 days out from now East Asia advertises a quick moving trough starting in the west which swings through the US, gaining amplitude as it progresses. This equates to a trough over the Central/Eastern US around the 13th of December +/- a few days. 

 

 

For anyone who cares, threw together a quick graphic representing what I mentioned above. The red text is the date in which it's projected to hit the US, and the overlay on each image demonstrates the correlation points to East Asia. Obviously nothing is perfect when it comes to meteorology, but figured I could throw something together to follow along with. Sorry if the image is huge, this forum doesn't seem to downsize images automatically

 

http://i.imgur.com/bxODI60.jpg

[TT-SEA]

Models are much drier for tomorrow now and much wetter for Thursday.   No chance of a warm day on Thursday now.   ECMWF led the way with that change.

[Jesse]

Certainly some signs of arctic air making it into the lower 48 this month, based on some recent runs.

[MR.SNOWMIZER]

12 is starting to look good for some mountain snow.

[Timmy]

12z gfs looks great beyond hour 200.  deep trough after deep trough.  and of course ends with lowland snow.

[TT-SEA]

Nice day.

[MR.SNOWMIZER]

Nice day.

Its a nice any day we have our health. Ask me how i know.

[TT-SEA]

Its a nice any day we have our health. Ask me how i know.

 

 

That goes without saying.

 

It is also a nice day weatherwise.

[Jesse]

Pretty good consensus developing for a cool, troughy period starting around December 10. Both the GFS and Euro ensembles strongly hinting at this.

 

If that pans out color me surprised. I was fully prepared for another +ENSO torchfest like December 2014.

[HighlandExperience]

Pretty good consensus developing for a cool, troughy period starting around December 10. Both the GFS and Euro ensembles strongly hinting at this.

.

According to Phil that is impossible.

[MR.SNOWMIZER]

That goes without saying.

 

It is also a nice day weatherwise.

Yes, i love to see the low humidity, it has so many positive effects. Amazing how fast the sun can dry everything out.

[luvssnow_spokane]

I really feel that something will be coming for us in December this year... I think we will all be pleasantly surprised.    OMG!! I just jinxed it!!!!!

[TT-SEA]

Does anyone have the website handy that shows the spaghetti-type graphs of the GFS ensembles?

 

 

Check the ensemble mean section of each run... the left image is the mean and the right image shows the spaghetti chart.

 

http://mp1.met.psu.edu/~fxg1/ewallmref.html

[ShawniganLake]

Does anyone have the website handy that shows the spaghetti-type graphs of the GFS ensembles?

Or did you mean this?

 

http://www.wetterzentrale.de/topkarten/tkavnmgnam.htm

 

http://www.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

[Front Ranger]

Models are much drier for tomorrow now and much wetter for Thursday.   No chance of a warm day on Thursday now.   ECMWF led the way with that change.

 

So no mid 60s for PDX then? Shocking that didn't pan out.

[TT-SEA]

So no mid 60s for PDX then? Shocking that didn't pan out.

 

 

Could have panned out if the ULL held offshore through the afternoon.    The ECMWF showed strong southerly flow and good mixing with a warm air mass.    But the ULL will not stay offshore through the day... so the warm spike probably comes at night and then it rains all day.   It all comes down to timing like I said earlier.       

 

Even so... the WRF still shows temps getting up to around 60 south of PDX on Thursday.   12Z ECMWF shows the exact same thing.   

 

http://www.atmos.washington.edu/mm5rt/data/current_gfs/images_d2/tsfc.57.0000.gif

[Jesse]

So no mid 60s for PDX then? Shocking that didn't pan out.

Extreme trolling tends to backfire every now and then.

[TT-SEA]

So no mid 60s for PDX then? Shocking that didn't pan out.

 

It was definitely worth mentioning since the ECMWF and WRF both showed it happening at just 4 days out and would have been interesting.     We are here to discuss weather.    But the timing did not work out.   Like so many over-hyped cold events by people whose entire existence seems to revolve around having negative departures in the record books!     

[TT-SEA]

I was thinking of what Shawnigan posted but thanks for the extra link Tim. The more bookmarked websites the better.

 

 

No problem.

[crf450ish]

 

 

Another sight for sore eyes is the recent return to robust positive OLR anomalies (5N - 5S) centered on 180.  A very definite anti El Nino signal.  Pretty interesting how it turned cold right after that change took effect.

 

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/olra_c.gif

 

Just curious, but if this was interpreted to show signs of anti-El Nino, then how did we end up with the greatest El Nino since 98'? I'm just trying to understand. Also, how could one assume a warm(er) December is in store after a rather lengthy cold snap in late November? From what I understand, its tied to MJO. 

 

Trying to educate myself here so I can move towards reading and interpreting models and information on my own. 

[Front Ranger]

12z Euro hour 216.

 

 

 

[Front Ranger]

It was definitely worth mentioning since the ECMWF and WRF both showed it happening at just 4 days out and would have been interesting.     We are here to discuss weather.    But the timing did not work out.   Like so many over-hyped cold events by people whose entire existence seems to revolve around having negative departures in the record books!     

 

Is there any other kind?

[TT-SEA]

12Z ECMWF ar 240 hours... good for the mountains at least.    

 

http://old.ecmwf.int/products/forecasts/d/getchart/catalog/products/forecasts/medium/deterministic/msl_uv850_z500!Geopotential%20500%20hPa%20and%20Temperature%20at%20850%20hPa!240!North%20America!pop!od!oper!public_plots!2015120112!!chart.gif

[Deweydog]

Is there any other kind?

Grave danger?

[BLI snowman]

12z Euro hour 216.

 

 

get_orig_img.png

 

850mb temps almost get below freezing on this run.

 

Winter gone wild. 

[TT-SEA]

850mb temps almost get below freezing on this run.

 

Winter gone wild. 

 

 

Pretty crazy!  

[Front Ranger]

Excellent trends on the Euro.

[Front Ranger]

850mb temps almost get below freezing on this run.

 

Winter gone wild. 

 

We're dealing with the Polar Vortex from hell here. Baby steps.