December 2016 Observations and Model Discussion for the Pacific Northwest

[MossMan]

Worst Euro run in years tonight!

Decades really...not sure I can go on knowing that Euro run is now out there in computer land for all to see.

[Heavy Snow]

Need to amplify that waveguide to dig the trough. Otherwise it's a flatter wavetrain, more progressive US trough, and a quicker/easier return to a +EPO/+AO as 120E forcing takes over. Bad run.

 

It looks like it might try to do something at day 8. Similar to what the GFS was hinting at.

[luterra]

Marys Peak @ 4000 ft in the coast range just dropped to 19 degrees (-7C).  Current modeled temps are -3C at 925mb and -1C at 850mb.  Upslope effect, more or less consistent with adiabatic lapse rate from our 29F in the valley.

 

Hoping this means the cold air is deeper than modeled, more snow, less ice...

[TT-SEA]

Perfectly calm here so far.

 

Wind was cranking in North Bend an hour ago though.

[Kayla]

Big blast headed for the NW on day 9 with building heights in the SE and Midwest.

[Front Ranger]

Worst Euro run in years tonight!

 

Things get wonky at day 8. Looks like it's about to kick up a big ol' SE ridge, just as the Pacific collapses.

[Phil]

It looks like it might try to do something at day 8. Similar to what the GFS was hinting at.

Looks like the beginning stages of a +EPO vortex to me. Euro loves to torque troughs SW along mountainous terrain so maybe it pulls one of its BS stunts in that regard but overall, right from day one I don't like the look of the run.

[Front Ranger]

Need to amplify that waveguide to dig the trough. Otherwise it's a flatter wavetrain, more progressive US trough, and a quicker/easier return to a +EPO/+AO as 120E forcing takes over. Bad run.

 

I still like the direction it headed in days 4-5, compared to the 12z. Came closer to tilting the ridge, as dewey pointed out will be necessary to get more of that PV air west.

 

I mean, it's well established the models are all over the place right now. I'm just looking for some sort of trend here, and all 0z runs moved in a better and somewhat similar direction in the mid range.

[Phil]

I still like the direction it headed in days 4-5, compared to the 12z. Came closer to tilting the ridge, as dewey pointed out will be necessary to get more of that PV air west.

 

I mean, it's well established the models are all over the place right now. I'm just looking for some sort of trend here, and all 0z runs moved in a better and somewhat similar direction in the mid range.

Well, I think it moved in the wrong direction all around. Right from the beginning, the macroscale waveguide across the Pacific was flatter. That's a dagger every time, no exceptions.

[Front Ranger]

Big blast headed for the NW on day 9 with building heights in the SE and Midwest.

 

Certainly gets things cold at day 9. -13C for SEA. -16C for Vancouver.

[Jesse]

I still like the direction it headed in days 4-5, compared to the 12z. Came closer to tilting the ridge, as dewey pointed out will be necessary to get more of that PV air west.

 

I mean, it's well established the models are all over the place right now. I'm just looking for some sort of trend here, and all 0z runs moved in a better and somewhat similar direction in the mid range.

Just perusing the 00z Euro I agree with this take.

[Deweydog]

It's a good thing we're hashing this out considering model uncertainty ends at midnight.

 

Anyone check the UJEAS???

[Front Ranger]

Well, I think it moved in the wrong direction all around. Right from the beginning, the macroscale waveguide across the Pacific was flatter. That's a dagger every time, no exceptions.

 

      

[Heavy Snow]

Looks like the beginning stages of a +EPO vortex to me. Euro loves to torque troughs SW along mountainous terrain so maybe it pulls one of its BS stunts in that regard but overall, right from day one I don't like the look of the run.

 

Yeah you were right about the Arctic Blast headed into the Midwest next week when the EURO first showed it giving us an epic blast. Though this time around looks like there is better model agreement with the GFS and GEM that it might be different this go around.

[Kayla]

Certainly gets things cold at day 9. -13C for SEA. -16C for Vancouver.

 

Yeah, not bad. But block doesn't hold and SE ridge is pretty weak, but it's day 9... As you say, best we can do at this point is look for some sort of trend.

[Jesse]

It's a good thing we're hashing this out considering model uncertainty ends at midnight.

 

Anyone check the UJEAS???

Oh god I remember that thing.

[Phil]

Sorry, lol.

 

Flat waveguide --> shift in EA-NAMT ratios -> NPAC jet breaks through (day 9) --> SE ridge gets blown apart --> transition into zonal regime.

[Front Ranger]

Oh god I remember that thing.

 

The hugeass!

 

Best forecast model ever that wasn't actually a model.

[Phil]

I'm done ranting my arse off. Goodnight all.

[Deweydog]

PV is over the NE Pacific at day 10! Should have a much easier time moving toward us from that position!

[snow_wizard]

Pretty hard to be unhappy with tonight's model runs. Very interesting possibilities.

[luvssnow_spokane]

Pretty hard to be unhappy with tonight's model runs. Very interesting possibilities.

Yep ... but been there done that.

[snow_wizard]

Fun to see the goodies within the range of the WRF. Pretty deep cold spell and then a big snow and about to get colder again at the end.

[snow_wizard]

Yep ... but been there done that.

As I say...as long as that mega block is there we have a great shot.

[SilverFallsAndrew]

Down to 22now

[Tyler Mode]

Wind is pretty incredible out here tonight. Probably the strongest east winds since we moved out here in 2010.

 

For sure...very strong here in BG as well.  Peak gust of 27, but coming in very loud bursts. 

[epiceast]

The hugeass!

 

Best forecast model ever that wasn't actually a model.

https://encyclopediadramatica.se/WeatherManKevin

He got his own ED page now. I wonder if he actually made any real money off his stunts.

 

Edit: Reading that was an awesome distraction from writing haha It's a bit over the top might violate the all audience friendly rules of the forum though(no obscene images however)

[Heavy Snow]

The updated run of the 00z EURO operational actually has some pretty cold temperatures for PDX. Even if we just get a glancing blow, this just goes to show you know bitter cold the Arctic airmass is going to the Midwest.

 

Highs next ten days.

 

Thu: 32/30

Fri: 34/30

Sat: 44/33

Sun: 44/37

Mon: 43/36

Tue: 41/32

Wed: 32/25

Thu: 31/27 - Snow/Ice storm (3-6" PDX Metro, up to 10"-12" Columbia/Cowlitz County)

Fri: 36/27

Sat: 23/14

[Perturbed Member]

06z NAM QPF is the same as the 00z NAM. Surface temps running about 1-2 degrees cooler. Keeps PDX freezing even by about 10 PM tomorrow and warms very slowly into the night.

[Heavy Snow]

The updated run of the 00z EURO operational actually has some pretty cold temperatures for PDX. Even if we just get a glancing blow, this just goes to show you know bitter cold the Arctic airmass is going to the Midwest.

 

Highs next ten days.

 

Thu: 32/30

Fri: 34/30

Sat: 44/33

Sun: 44/37

Mon: 43/36

Tue: 41/32

Wed: 32/25

Thu: 31/27 - Snow/Ice storm (3-6" PDX Metro, up to 10"-12" Columbia/Cowlitz County)

Fri: 36/27

Sat: 23/14

 

SCORE! The updated run of the 06z GFS shows an Arctic Blast arriving on Tuesday and snow/ice storm for PDX next Thursday, the same day as the EURO! Then a reload at day 9 with more snow! Check out the snow totals through day 10!

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/132/850th.us_nw.pnghttp://maps1.pivotalweather.com/maps/models/gfs/2016120806/174/prateptype_cat.us_nw.png

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/216/500h_anom.na.png

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/216/prateptype_cat.us_nw.png

 

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/240/850th.us_nw.png

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/240/prateptype_cat.us_nw.png

http://maps1.pivotalweather.com/maps/models/gfs/2016120806/240/snku_acc.us_nw.png

[westcoastexpat]

I have a confession.

 

I'm really excited about tonight.

 

Admittedly those of us in the northern reaches of this subforum have had less of a rollercoaster ride with respect to the model runs, although our snow amounts have continued to plummet with each run. I've been quiet lately because I didn't want to post that I'm so excited about this event since it looks to be mostly snow up here.

 

I'm more of a conservative forecaster, and these overrunning events are certainly tricky, especially with the local effects due to our complex terrain.

 

I'm admittedly not very confident for areas south of say Arlington. I can see why the NWS is a little clueless. That's not to say that a surprise won't be in store, but I think the dynamics are going to hinder any potential widespread 4"+ which is kind of my subjective floor for a decent "event". I think the usual areas with beneficial local effects could make it, but I'm not optimistic for the metro areas. But the models have been terrible, even in the short range. I'm more interested to see some of the hi-res models like the HRRR and RAP, as shitty as they are, to latch onto a solution, at least as far as precip type goes. Small tweaks could make all the difference. This really is a thread the needle type of scenario--naturally. I swear the life expectancy for weather weenies in the PNW has to be lower from all the anxiety.

 

But to shed some optimism, I don't see the cold air scouring out anytime soon. There have been hints of the arctic air extending this far west on and off for some time, and the frequency of those colder runs continues to grow. I find the models are usually pretty awful with scouring colder air masses on the periphery. Although I don't see a strong signal to guarantee that the cold air holds, I wouldn't be surprised to see "warm ups" that remain decently cold, followed by more waves of arctic air.

 

Not a climatologist, so going out on a limb here, but I'd say:

 

-Colder than normal temperatures remain for the next two weeks, with the week prior to Christmas being potentially record breaking

-Above normal snowfall over the next two weeks

-Last week of December is a total toss up between slightly chilly or majorly cold

-Early January will remain below normal

-Rest of January will return to a wetter, milder pattern

 

Keep in mind that I don't know what I'm talking about But I do think the December is going to remain a solidly cold month and I would bet on at least one major snowfall (6"+) for most posters in this sub. I do think that metro Vancouver/Bellingham will have an opportunity to majorly cash in, which is something I haven't said in a really long time.

[westcoastexpat]

And my thoughts on snow for the Thursday night-into the weekend period...

 

I'm looking at 5" for the Vancouver/Bellingham areas into early Saturday. The real question for me is how the low behaves Saturday into Sunday. This is where the northern sub has a real chance to score in major (snow totals nearing a foot), or get totally screwed. I think the Canadian suite is a little too aggressive, but I don't buy into the drier/milder NAM/GFS solutions. Wet bulb is really going to help hold off on the transition, and I don't see any significant WAA in the upper levels to screw these areas prematurely.

 

My call for the northern sub areas: 8" for metro Vancouver/Bellingham by Sunday night. I just don't see the changeover happening quickly, if at all. Barring some variance due to local effects like shadowing or dry air scouring the onset of precip.

[catnip]

And my thoughts on snow for the Thursday night-into the weekend period...

 

I'm looking at 5" for the Vancouver/Bellingham areas into early Saturday. The real question for me is how the low behaves Saturday into Sunday. This is where the northern sub has a real chance to score in major (snow totals nearing a foot), or get totally screwed. I think the Canadian suite is a little too aggressive, but I don't buy into the drier/milder NAM/GFS solutions. Wet bulb is really going to help hold off on the transition, and I don't see any significant WAA in the upper levels to screw these areas prematurely.

 

My call for the northern sub areas: 8" for metro Vancouver/Bellingham by Sunday night. I just don't see the changeover happening quickly, if at all. Barring some variance due to local effects like shadowing or dry air scouring the onset of precip.

Works for me!

[catnip]

Current overnight low here is 14.7.

 

Looks like I may surpass that next week.

[Jesse]

Pretty insanely good ensemble support for the insanely good 06z.

 

I'm still skeptical.

[Timmy]

Pretty insanely good ensemble support for the insanely good 06z.

 

I'm still skeptical.

Yeah, would be an awesome morning for nerds to wake up to if not for the NWS loosing confidence and HRRR not looking bullish. 06z nam and gfs weren't bad.

[Phil]

Both the 06z GEFS and 00z EPS improved the pattern in the middle and long range, and bring the Arctic air closer to the PNW overall. The 00z EPS looked nothing like the 00z ECMWF operational so that was a relief, though I'd still like to tweak it somewhat.

[Deweydog]

6z... Good one. It's always had a good sense of humor.

[BLI snowman]

Radar looks horrible right now. Still a long ways off from anything.

[MossMan]

6z... Good one. It's always had a good sense of humor.

Why can't the 12z ever lighten up and have a sense of humor like the 6z does? I hate having my mornings at work continually ruined by that grumpy old bastard.