December 2015 in the Pacific Northwest

[BLI snowman]

 

Coming through, loud and clear!

 

Note the word "at" followed by "best".

 

Also note that I'm prognosticating for the mere earth-bound locations around our region. The divine holy zen spots such as OLM are likely to get absolutely plastered with wet cement. 

[Deweydog]

2009 was kind of a freak thing and isolated strictly to the Portland area.

 

But it goes to show...the highly unlikely can and does happen.

Yeah, those well-mixed, progressive WNW flow snowstorms can be a real ***** to forecast...

[TT-SEA]

When Matt starts getting excited about an event... I am all in.

[BLI snowman]

I just dislike propaganda put out by certain people and then the expectation that everyone buy into the propaganda. I don't dislike the love of cold and snow. I love cold and snow. But a real discussion is often derailed by delusion. You see the situation clearly. Matt does as well. So does Jared. And, as I mentioned, I really like Rob's detailed analysis.

 

The bottom line is that things haven't really trended towards a meaningful pattern change at this point. We're a ways off still. The real story has been and will continue to be the filthy amounts of rain, either though it's understandably far less enticing a discussion to have.

 

Also, in looking at our wettest Decembers on record, there's really no clear signal. Big mixed bag of patterns the rest of the winter. Decembers like 1996, 1955, 1933, 1917, 1882, and 1867 really stand out for their rain and there's some huge contrasts there in JFM. 

[Gradient Keeper]

*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*
*.*.*. MERRY CHRISTMAS .*.*.*
[Model Countdown] 12/17/15
Next up................
*6z GFS in 1 hour 28 minutes
12z GFS in 7 hours 28 minutes
12z GEM in 8 hours 27 minutes
12z ECMWF in 9 hours 51 minutes

[Deweydog]

When Matt starts getting excited about an event... I am all in.

That clueless prick only comes here to mess with people's heads.

[DareDuck]

I would say decent chance that several people on this forum (besides you) see snow in the next 10

It's snowing here right now. Thinking it will switch to rain by daylight tomorrow.

[Front Ranger]

It's snowing here right now. Thinking it will switch to rain by daylight tomorrow.

 

Progressive.    

[BLI snowman]

This thing is pretty hit/miss GFS-lite model output most of the time, but it shows about 3.7" of rain at PDX on Thursday and it usually doesn't error too far on the wet side.

 

 

Gonna be some problems if that happens.

[Gradient Keeper]

Through day 9-10 6z is mirroring 00z GFS run. No changes really or improvements. Just too progressive way more than the EURO. Go EURO! Onto 12z!

[Phil]

PV breaks up. A least it will shake things up. We might score at the onset of that change.

Question is, will the tropical forcings still favor NPAC height rises by the time it breaks up (mid/late January)?

[Phil]

Never said that. Usually quotation marks are for quoting people.

You kind of implied it.

 

There is plenty of cold air sitting just to your north on these runs. The PV is not what's holding that from sliding a little further south.

[TT-SEA]

Troutdale is reporting rain... snowing in the eastern gorge. Must be freezing rain somewhere in between.

[MossMan]

Still sitting at 31 degrees here.

[ShawniganLake]

33.6F with light snow falling here. Not heavy enough to accumulate.

[TT-SEA]

33.6F with light snow falling here. Not heavy enough to accumulate.

 

Nice.    Is this a cold air damming situation up there like the Hood Canal?

[ShawniganLake]

Nice. Is this a cold air damming situation up there like the Hood Canal?

That looked to be the case by what the models were showing. The winds have been blowing ENE across the strait of Georgia all night. WRF showed negative 925mb temps hugging the east side of Vancouver island most of this morning.

[SilverFallsAndrew]

It is snowing at The Dalles. 33 degrees. 

[TT-SEA]

06Z GFS bottoms out at -7C on Christmas night... and the meteostar output shows precip at that time.    Although the operational run is sparse... there is a low offshore.  

 

It is sort of cool that the best chance of lowland snow in the next couple weeks does happen to land on Christmas.  

 

 

http://wxweb.meteostar.com/sample/sample.shtml?text=ksea

 

http://mag.ncep.noaa.gov/data/gfs/06/gfs_namer_210_precip_p03.gif

[ShawniganLake]

Starting to accumulate now. Temp down to 33F. First snow I have seen in over a year. Hard to believe considering we average a little over 30".

[TT-SEA]

Precip is just starting to arrive in the Seattle area this morning as the models showed.     Roads are still totally dry.   

 

37 here with a dewpoint of 29 and dry.

[TT-SEA]

Starting to accumulate now. Temp down to 33F. First snow I have seen in over a year. Hard to believe considering we average a little over 30".

 

 

Very cool... do you think it will stay snow as the precip gets heavier?   I am not sure how it works up there in this situation.  

[ShawniganLake]

Very cool... do you think it will stay snow as the precip gets heavier? I am not sure how it works up there in this situation.

Usually the heavier precip helps, at least until the upper levels warm or until a south wind scours out what cold air there is. Typically these are a rain to snow to rain situation. I was surprised it started as snow actually. Precipitation is modelled as being pretty light up here, looked like the 7-10am period might produce an inch or so. It's borderline, it's 40 degrees and raining only 5 miles from here and 500ft lower.

[TT-SEA]

Usually the heavier precip helps, at least until the upper levels warm or until a south wind scours out what cold air there is. Typically these are a rain to snow to rain situation. I was surprised it started as snow actually. Precipitation is modelled as being pretty light up here, looked like the 7-10am period might produce an inch or so. It's borderline, it's 40 degrees and raining only 5 miles from here and 500ft lower.

 

Is the lake there at 500ft?

[Phil]

Yeah, this isn't responsible for the progressive nature of the pattern. Just a normal early-winter PV, correct?

 

What a monster. (Image credit: Michael Ventrice/WSI)

 

[TT-SEA]

Mid 40s and rain in Moscow this weekend and next week... typical Christmas weather there I assume.  

 

Low 60s and partly cloudy in London this weekend.   Just normal, pleasant May weather.  

 

Seems like the Western US is the only place cold at this latitude. 

[ShawniganLake]

Is the lake there at 500ft?

The lake itself is around 400ft, and I am just a little ways up the hill from the lake. Just checked and its 41.4F and raining at Mill Bay, which is near the ocean about 6 miles from here.

[Gradient Keeper]

6z GFS Ensembles 850mb mean temps about the same. The only changes I note were the new cluster of -5c to -10c after December 27th. Would like to see that increase and to get rid of the warmer members. 500mb anomalies a touch better.

 

Oh, I tried to ' like ' a few posts, but I got this prompt instead

 

An error occurred

You have reached your quota of positive votes for the day.

-------------------------------------------

Now how am I supposed to show my agreement or like for other members comments, analysis, or whatever, if I can't do that. It'll be a rough day for me, but I'll get through this somehow. Onto 12z!

 

12z GFS in 44 minutes

12z GEM in 1 hours 44 minutes

12z ECMWF in 3 hours 6 minutes

[Gradient Keeper]

It is snowing at The Dalles. 33 degrees. 

I like this

 

06Z GFS bottoms out at -7C on Christmas night... and the meteostar output shows precip at that time.    Although the operational run is sparse... there is a low offshore.  

 

It is sort of cool that the best chance of lowland snow in the next couple weeks does happen to land on Christmas.  

 

 

http://wxweb.meteostar.com/sample/sample.shtml?text=ksea

 

http://mag.ncep.noaa.gov/data/gfs/06/gfs_namer_210_precip_p03.gif

I definitely like this

 

Starting to accumulate now. Temp down to 33F. First snow I have seen in over a year. Hard to believe considering we average a little over 30".

Nice. I like this

 

Yeah, this isn't responsible for the progressive nature of the pattern. Just a normal early-winter PV, correct?

 

What a monster. (Image credit: Michael Ventrice/WSI)

 

image.png

I like the knowledge, but I don't like the massive, consolidated PV

[Parksvillewx]

Go GFS Go! Output for Christmas Eve/Day here..

 

 

 

On another note, light rain and 36F here. Maybe chunky rain if precip rates pick up.

[crf450ish]

22 here this morning and dark clouds in the sky as the snow moves in. Not snowing yet, but monitoring doppler radar this morning, it seems as if the snow is tracking north east, coming in from the south west. Good setup for me to score some decent accumulation. 

[bainbridgekid]

Dumping at the pass with I-90 covered down to 1,700 feet.

 

Should be a monster couple weeks up there. Perfect timing.

[MossMan]

Dumping at the pass with I-90 covered down to 1,700 feet.

 

Should be a monster couple weeks up there. Perfect timing.

I just got done looking at the pass cams, gave me Goosebumps. So great to see after such a horrible past two years.

[westiztehbest]

Expecting 4" tonight with freezing rain.  Sitting at 19F.  

[MossMan]

 

6z GFS Ensembles 850mb mean temps about the same. The only changes I note were the new cluster of -5c to -10c after December 27th. Would like to see that increase and to get rid of the warmer members. 500mb anomalies a touch better.

 

Oh, I tried to ' like ' a few posts, but I got this prompt instead

 

An error occurred

You have reached your quota of positive votes for the day.

-------------------------------------------

Now how am I supposed to show my agreement or like for other members comments, analysis, or whatever, if I can't do that. It'll be a rough day for me, but I'll get through this somehow. Onto 12z!

 

12z GFS in 44 minutes

12z GEM in 1 hours 44 minutes

12z ECMWF in 3 hours 6 minutes

 

I know! Guess we need to petition Fred about an allowed number of "likes" increase!!

[Front Ranger]

Mid 40s and rain in Moscow this weekend and next week... typical Christmas weather there I assume.  

 

Low 60s and partly cloudy in London this weekend.   Just normal, pleasant May weather.  

 

Seems like the Western US is the only place cold at this latitude. 

 

China says hello.

[Front Ranger]

12z GFS no bueno. Offshore ridge is much weaker and less amplified. Downright wimpy, really.

[MossMan]

12z GFS no bueno. Offshore ridge is much weaker and less amplified. Downright wimpy, really.

So the Euro has been getting stronger with the ridge and amplification, and the GFS has been getting weaker?

[WS Snow]

Steady rain and 38 degrees in West Seattle

[Front Ranger]

So the Euro has been getting stronger with the ridge and amplification, and the GFS has been getting weaker?

 

This is the first run of the GFS with the ridge this weak. It's quite different than the last few runs.