December 2016 Observations and Model Discussion for the Pacific Northwest

[HighlandExperience]

I thought it would be snow already. Could fall apart before it produces anything.

Just had a heavy hail shower here.

[epiceast]

If they really get cranking they can create their own cold to some extent.  A bit of that Fraser River air would work magic though.

Yea the fact that northern CZ got killed off by the pierce/king county one is not a good sign. Usually you want the northernmost cz to be the dominant one and then slowly slide south given everyone an inch of snow. Right now I don't expect anybody north of Seattle to get snow tonight, and it's very questionable for people south of Seattle, since we lost about 50 miles of cold.

[Phil]

The PV is much stronger in the upper levels this run. Also more circular and organized. Boo.

[TT-SEA]

Just had a heavy hail shower here.

 

Hail can happen at warm temperatures though.   Not really a sign that will actually snow here.

 

It was fairly bright and raining moderately.... now its really dark and not doing much.

[HighlandExperience]

Hail can happen at warm temperatures though. Not really a sign that will actually snow here.

 

It was fairly bright and raining moderately.... now its really dark and not doing much.

It was just nice not to see rain.

[TT-SEA]

It was just nice not to see rain.

 

 

Absolutely.

 

Its been raining here for 48 hours straight.  

[Phil]

Heh, that Eurasian wave still manages to bifurcate it below 80mb..does the trick and the NPAC is then able to follow suit.

[Jesse]

I can report that east winds are kicking in here at the Chamberlain Lake Rest area between Lyle and Bingen.

[snow_wizard]

I'm getting some ice pellets here, but it has only cooled to 40 so far.

[SilverFallsAndrew]

White Christmas?!

[MR.SNOWMIZER]

Heh, that Eurasian wave still manages to bifurcate it below 80mb..does the trick and the NPAC is then able to follow suit.

I know, I seen that my self..

[Phil]

I know, I seen that my self..

Lol.

 

I kinda spoke a bit too soon. This run ends up being a battle.

[ShawniganLake]

It's let up a bit but still going pretty steady here. Probably nearing an inch so far.

 

http://i131.photobucket.com/albums/p286/jemeric/IMG_3777_zps0wdtjhme.jpg

You did better than the lowest elevations of cowichan. Next to nothing in Duncan. But more just a few feet up the hill.

[TT-SEA]

This band is worthless... looks like drier air filtering now.  

[Perturbed Member]

The GFS has been utterly stupid recently, the run to run variation is pathetic. What is this nonsense?

[Perturbed Member]

PDX NWS thinks the NAM is on some sort of illicit substance:

 

A weak, barely evident center of circulation could sneak
by to the south and only overspread precipitation to areas south of
Salem, however on the other hand, the low center could wrap up and
bring a stronger surface low up the Oregon coast (NAM). The most
likely solution is probably somewhere between these two extremes. It
is also worth mentioning that the NAM solution has been completely
thrown out for this forecast package as it seems to be way overdone
with the strength of the low (A commonly known issue greater than 36
hours out).

[snow_wizard]

Total bummer.  I got enough moderate rain to equate to a couple inches of snow if had been colder.

[Jesse]

Pretty good agreement in the GFS ensembles for the situation Wed/Thur. Almost all the warm members are gone now.

[snow_wizard]

A white Christmas is certainly on the table.  The 18z has a nice cold shot with snow around there.  Nice to see many models runs hinting at cold later in week two again.  The thing I find interesting is the cold shot being shown is yet another one to feature Fraser outflow.

 

The only December I can think of like this one is 1971.  That month was marked by frequent, but not overly dramatic cold shots.  Seattle did better with snow in 1971, but this isn't over yet.  January is when the mother lode hit Seattle that winter.

[Goducks09]

PDX NWS thinks the NAM is on some sort of illicit substance:

 

A weak, barely evident center of circulation could sneak

by to the south and only overspread precipitation to areas south of

Salem, however on the other hand, the low center could wrap up and

bring a stronger surface low up the Oregon coast (NAM). The most

likely solution is probably somewhere between these two extremes. It

is also worth mentioning that the NAM solution has been completely

thrown out for this forecast package as it seems to be way overdone

with the strength of the low (A commonly known issue greater than 36

hours out).

 

If they are right in their assumption that the solution is somewhere between those two scenarios, then the northern Willamette Valley is looking a pretty significant snow event.  I've been burned too many times to be on board with this though - I sort of feel like they are wish-casting as much as we do.

[Perturbed Member]

Looks like they want to be a bit more conservative this time after last week:

 

The decision not to issue a winter storm watch was not made lightly,
but at this time it is tough to pinpoint a specific area. Also, with
the wide range of QPF possibilities, confidence is not quite to the
50% confidence threshold in warning criteria snow for valley
locations. If the 00Z model suite comes into better agreement, the
night shift may be able to better pinpoint the areas which will need
a Winter Storm Watch.

[snow_wizard]

Pretty good agreement in the GFS ensembles for the situation Wed/Thur. Almost all the warm members are gone now.

I'll say. The mean is back down to -11 for Seattle again. Third consecutive run to show decent cold late in the month.

 

Now if we could all score some snow on Wednesday!

[Perturbed Member]

If they are right in their assumption that the solution is somewhere between those two scenarios, then the northern Willamette Valley is looking a pretty significant snow event.  I've been burned too many times to be on board with this though - I sort of feel like they are wish-casting as much as we do.

 

 

 

Indeed an in between solution would be ideal for PDX and yes the PDX NWS do seriously come across as wish casters sometimes. At the same time though, the NAM and the GFS have  been jumping around quite a bit, especially the GFS. At the moment I am a bit more inclined to stick with the euro with maybe a slightly further north track, but then again maybe I'm wishcasting too.

[TT-SEA]

Getting some wet non-sticking snow now.

[snow_wizard]

The ECMWF 45 day ensemble is quite good. Shows a -PNA right through mid January. The control shows major cold late this month through early Jan. White New Years on the table also it would appear.

 

This is well supported by the CFS.

[MossMan]

Down to 33 degrees as of an hour ago when I pulled back into work with a drizzle/snow mix! 

Oh and I see we are in fact verging on Menstrual Monday again after seeing the wild placement difference between the GFS and the NAM! All I can say is GO NAM!

[Front Ranger]

The only December I can think of like this one is 1971.  That month was marked by frequent, but not overly dramatic cold shots.  Seattle did better with snow in 1971, but this isn't over yet.  January is when the mother lode hit Seattle that winter.

 

As someone else pointed out, 1992 was somewhat similar as well. 1961 and 1984 may end up being decent matches, too.

 

Of course, it's really too soon to say, as the second half of the month could be drastically warmer/colder than any of those years.

[Goducks09]

Down to 33 degrees as of an hour ago when I pulled back into work with a drizzle/snow mix!

Oh and I see we are in fact verging on Menstrual Monday again after seeing the wild placement difference between the GFS and the NAM! All I can say is GO NAM!

Will Menstrual Monday be followed by Tampon Tuesday?

[MossMan]

Will Menstrual Monday be followed by Tampon Tuesday?

I believe that is the normal progression and will most likely be needed by tomorrow's 12z runs...either for us up here, or you guys down there...

[MossMan]

Why can't we at least get a dusting of snow before going into cold...grrrrr! 

[crf450ish]

Might try my hand at ice art throughout this week. It's going to be very cold, even for daytime highs. Going to spritz some water onto the lilacs and cherry tree out front and see what I can whip up for a layer of ice. Will have to bring the garden hose inside in between.   

[Poulsbo Snowman]

Will Menstrual Monday be followed by Tampon Tuesday?

Only if you pull the right strings.

[Sometimesdylan]

http://www.weather.gov/images/afc/BeringStorm12Dec2016_labels.gif

 

Meanwhile in the Bering Sea...

 

NWS Says "

This JMA Himawari-8 satellite loop shows a rapidly intensifying storm force low (wind speeds > 48 knots/53 MPH) in association with a satellite detected dry air intrusion (the dry air highlighted in the loop), a special signature meteorologists look for during the early phases of cyclone development. This signature is the early warning alert for a significant storm with potentially damaging winds and high seas. The color enhancements on this satellite product highlight the differences between dry (Red), tropical (Green) and cold (Blue) air masses, then these colors are overlaid to aid meteorologists in interpreting the complex meteorological processes involved. Weather forecasting in Alaska depends on critical satellite information like this to predict high impact storms."

[Deweydog]

Total bummer. I got enough moderate rain to equate to a couple inches of snow if had been colder.

There's a first time for everything.

[SilverFallsAndrew]

Winter Storm watch for most of central and eastern Oregon.

[TT-SEA]

Down to 31.8 here with sticking snow but radar looks pathetic now.  

[Prairiedog]

Mark is saying pretty much what the NWS is saying that no WSA to be issued yet as the models are all over the place.  Reading between the lines he was almost hinting that most of the moisture was staying south as he emphasized that the southern part of the state would be hit alone with Eastern Or.  Don't want to read anything into something that's not there.  Just felt that he was leaning that way to me a little. 

[SilverFallsAndrew]

Mark is saying pretty much what the NWS is saying that no WSA to be issued yet as the models are all over the place.  Reading between the lines he was almost hinting that most of the moisture was staying south as he emphasized that the southern part of the state would be hit alone with Eastern Or.  Don't want to read anything into something that's not there.  Just felt that he was leaning that way to me a little. 

 

As of right now I would say:

 

PDX: T-2"

SLE: 2-4"

EUG: 3-6"

 

The further south it trends the less snow from N to S the further north it trends the less snow from S to N....Yeah not high confidence yet

[SilverFallsAndrew]

Nice to see offshore flow at The Dalles now. 

[SilverFallsAndrew]

I will say this. If you are looking for a meaningfully cold January, everything is lining up as well as could have been imagined. The only fly in the ointment so far is the mild October, but overall the progression has been excellent IMO.