December 2016 Observations and Model Discussion for the Pacific Northwest

[SilverFallsAndrew]

Hope DJ's mom is still doing ok...he is usually awake by the Euro.

 

I hope so too. Sounds like he had a rough day yesterday so it would be nice if he was getting some rest. 

[Front Ranger]

Fairly significant differences again by day 5 between GFS and Euro, as GFS is more progressive.

 

 

 

 

 

[liquidsnow]

I definitely like where this is going!

 

http://maps1.pivotalweather.com/maps/models/ecmwf/2016120212/120/500h_mslp.na.png

[Heavy Snow]

KING EURO ALERT!

[westcoastexpat]

I have a gut feeling that this is only the beginning. We have a very decent shot at having one of the coldest winters in 40 years. I'm almost certain that this will be the start of a new regime. History tells us that this is going to be an epic winter.

[stuffradio]

Yesterday's CFSv2 monthly for Jan was pretty torchy for the PNW. Today it's colder than avg. Score!

[MossMan]

I have a gut feeling that this is only the beginning. We have a very decent shot at having one of the coldest winters in 40 years. I'm almost certain that this will be the start of a new regime. History tells us that this is going to be an epic winter.

That's more like it!!!

[Kayla]

I'm headed to our property out in Bozeman later next week...It's looking just a wee bit nippy! 850s of -21C! Looking forward (or not) to some true arctic air at an added bonus of 5,000ft of elevation!

[SilverFallsAndrew]

Yesterday's CFSv2 monthly for Jan was pretty torchy for the PNW. Today it's colder than avg. Score!

 

Always go with the cold run!

[westcoastexpat]

That's more like it!!!

I'm learning ;-)

[crf450ish]

I have a gut feeling that this is only the beginning. We have a very decent shot at having one of the coldest winters in 40 years. I'm almost certain that this will be the start of a new regime. History tells us that this is going to be an epic winter.

I like your attitude. Low solar activity plays a huge role in our overall pattern (as well as the rest of the earth). I would like to see the glaciers return and begin encroaching into places never before seen in the last century.

[FroYoBro]

I like your attitude. Low solar activity plays a huge role in our overall pattern (as well as the rest of the earth). I would like to see the glaciers return and begin encroaching into places never before seen in the last century.

 

Good luck with that. Glaciers are disappearing all over the place. 

[HighlandExperience]

[stuffradio]

Always go with the cold run!

I just go with what I like to see, TBH.

[FroYoBro]

Although we should be focusing on Monday/Tuesday more than anything at this point, the 12z Euro shows widespread 3-4 inches falling on Friday morning from Olympia-Canada. Hangs on to the cold air longer than the 00z.

 

That being said, 850s are only -3 to -4c and 925s are 0c around Olympia to -3 near Bellingham, so it's a little suspicious.

 

More importantly, much more precip around for Monday than the 00z.

 

That event will not rely on super cold 850s for snow. Overrunning events depend on offshore flow and low level cold air. Mostly just watch the temperatures up above like 850 to see if you are going to get snow/freezing rain/sleet. 

[Kayla]

Nice write up by the Portland NWS this morning. They share similar thoughts I have for the upcoming event(s) -

 

"Sunday night through Thursday...Sunday night we will
start to see significant cool air moving into the region, with our
first chance for significant snow in the Cascade foothills starting
Sunday night. By Monday morning, models show wet-bulb zero heights
getting down below 1000 feet. This coupled with 850 temperatures
around -5C to -6C, means the potential for accumulating snow down to
at least 1000 feet Monday morning with a secondary shortwave expected
to move across the region on Monday. Could see drying behind the
front overnight Sunday night which would help temperatures wet-bulb
down Monday morning for a chance of snow down to the Valley floor.
Paved surfaces may be too warm for much accumulation, but can`t rule
out an inch which would impact the Monday morning commute in valley
locations from Salem northward. South of Salem may start as more of a
mix of rain and snow. Midday, snow levels should come up a bit
allowing precipitation to turn to rain right around the Valley floor,
but could continue to see accumulating snow down to 1000 feet.
Precipitation turns back to showers Monday night with another brief
period where we may see snow all the way down to the Valley floor,
but drying behind the front should limit qpf Monday night.

Tuesday will be the coldest morning so far this year, with
temperatures generally down below freezing everywhere except along
the Coast. Will generally remain fairly cold through the day, with
temperatures in inland valley locations possibly not getting out of
the 30s. In addition to cooler temperatures, will also see easterly
winds start to increase Tuesday evening, particularly in and near the
Columbia Gorge, which could make it feel even colder Tuesday night.

Forecast later next week gets a little more uncertain with another
system expected to move across the area sometime between Wednesday
night and Friday night. This could be another high impact event,
especially with the earlier scenario which could overrun cold air
trapped in the Valley for a freezing rain scenario. The later
scenarios may be a less impactful cold rain event. Stay tuned to the
forecast for later next week as well." 

[SilverFallsAndrew]

King Euro gives me a good snow dump on Monday...

 

[bainbridgekid]

I don't have access to the Euro precip maps, but the overall picture looks much better than the GFS for both Monday and the overrunning event Thursday.

 

Long live the King.

[HighlandExperience]

I don't have access to the Euro precip maps, but the overall picture looks much better than the GFS for both Monday and the overrunning event Thursday.

 

Long live the King.

Someone please post a higher resolution precip map for EURO

[Jesse]

[SilverFallsAndrew]

The EURO is so different from the GFS.

[catnip]

The EURO is so different from the GFS.

 

No Kidding.

 

12Z Euro is a nice improvement on it's 00z run last night.

[Jesse]

The EURO is so different from the GFS.

I would way rather have it this way than the other way around. Euro is simply a superior model.

 

That heartbreaking 06z run is a thing of the past now.

[FroYoBro]

I would way rather have it this way than the other way around. Euro is simply a superior model.

 

That heartbreaking 06z run is a thing of the past now.

 

Just wait until you see the 18z! 

[Jesse]

Just wait until you see the 18z!

The block will be wimpier, wonkier, washed up and wife beating.

[HighlandExperience]

I will not rest until the Carbon Glacier reaches Wilkeson.

That would be something!

[HighlandExperience]

[Sometimesdylan]

Juneau forecast discussion this am:

 

FXAK67 PAJK 021734 CCA

AFDAJK

 

Southeast Alaska Forecast Discussion...CORRECTED

National Weather Service Juneau AK

834 AM AKST

.LONG TERM...Long range period mainly deals with a switch to a

much colder pattern that sticks around through most of next week.

The cool down will be a one two punch affair. The first shot will

be incoming from the W and SW as the cold air wraps around a lee

side low in the northern gulf. Even though the air mass started

out in the arctic the warm gulf waters will have modified the air

mass by the time it gets here. However, 850 mb temps still drop to

-10 to -12 C by Sat night which will be plenty cold enough for

the remaining precip in the panhandle to change over to snow as

early as Sat afternoon. QPF values will be rather low so any

accumulations will only be around a few inches though some areas

could see some higher amounts due to convergence or convective

enhancement.

 

Cold shot number two shows up late Sunday coming directly from the

Yukon this time. This is the air mass that will cause temperatures

to plummet into the teens and 20s or lower early next week. The

results of this will be two fold. First, winds will change to the

north and rapidly increase in the usual outflow areas. Gales

expected for many of these areas. Freezing spray also expected

with the high winds and low air temperatures in the northern inner

channels. Second result will be the drying out of the panhandle as

the northerly winds push what precip is left southward. Main

forecast changes were in this time period as model trends had the

precip and accompanying weak low in the gulf slower to push out

then what was in there previously. Used mainly nam for guidance in

this period for details on the outflow winds and timing on when

the precip ends.

 

Extended forecast remains cold as the cold northerly winds

continue to feed cold air from the Yukon into the panhandle. There

are indications that it will not be dry though. Guidance is

suggesting that a gale force front may approach the panhandle mid

to late next week and with cold air still entrenched in the inner

channels it will likely be mostly snow that falls. Agreement on

the track of the main low is up in the air though as scenarios

range from a track into Haida Gwaii to it wandering around the

western gulf. About the only thing we can say with some certainty

is that there will be a storm somewhere in the gulf in the latter

half of next week.

[Heavy Snow]

Last night's run of the 00z GEM looks really cold Wednesday morning as modified Arctic air arrives. This map shows lows in the upper teens to low 20s for the I-5 corridor. If this happens then everybody should start off as snow when the system arrives and it should be a lengthy overrunning/transition event.

http://maps3.pivotalweather.com/maps/models/ggem/2016120200/132/sfct.us_nw.png

[SilverFallsAndrew]

The updated run of the 12z GEM looks really cold Wednesday morning as modified Arctic air arrives. This map shows highs in the upper teens to low 20s for the I-5 corridor. If this happens then everybody should start off as snow when the system arrives and it should be a lengthy overrunning/transition event.

 

http://maps3.pivotalweather.com/maps/models/ggem/2016120200/132/sfct.us_nw.png

 

Those are lows. 

[Jesse]

That would be something!

It used to! A mere 12,000 years ago. Blink of an eye geologically.

[Bryant]

Euro snowfall maps for Western Washington anyone?

[Heavy Snow]

Those are lows.

Yeah I got too excited seeing the maps and said highs instead of lows LOL.

[SilverFallsAndrew]

Yeah I got too excited seeing the maps and said highs instead of lows LOL.

 

Even those lows verifying would be very impressive...Not to be a Debbie Downer, but I can't imagine they will verify. 

[westcoastexpat]

Those are lows.

Stop being pessimistic

[luvssnow_spokane]

[stuffradio]

Stop being pessimistic

This wasn't needed.

[Jbolin]

Personally I will not rest until a glacier covers Puyallup a.k.a. the swamp..

Goals man, Goals!

[Skagit Weather]

Euro snowfall maps for Western Washington anyone?

 

Courtesy of Scott Sistek on Twitter (https://twitter.com/scottskomo)

 

Euro snow for Monday

 

 

Euro snow for Thursday

 

[luvssnow_spokane]