November 2017 PNW Discussion Thread

[stuffradio]

Will this be a month of carrots and warning shots, or will we start to see the real deal? Time will tell!

[TigerWoodsLibido]

I'm thinking major snowstorm for all of us on Black Friday or so.  Huge deformation bands from Brookings to BC, 971 MB low sits of the coast of Crescent City/Eureka associated with an AR.

[Brian_in_Leavenworth]

Got this from a tweet by a met named Michael Clark, from BAMWX.com  This was from the Euro weeklies run a couple of days ago for November.

 

 

[snow_wizard]

I'm going to guess there will be a major trough late in the month which will really start to make things interesting.  I'm just going by the timing we are currently seeing...late Sept, mid Oct, early Nov, ...

 

The early month trough should bring some noticeably chilly weather and a little bit of lowland snow in some places.

[snow_wizard]

The WRF is considerably more agressive at bringing in cold air Thurday night and Friday than the 12z.  925s drop to -4 at BLI and -2 for SEA.  Some lowland snow being shown in places.  It is showing some really chilly low temps coming up.

[VancouverIslandSouth]

Faster timing, less moisture, and further south was a big theme of the models last winter for these sort of setups. Seems like the biases are playing out again. Temperatures will be plenty cold for snow, but now moisture that was initially predicted to hang around into Friday afternoon is finished early Thursday night.

[stuffradio]

00Z operational appears to be an outlier warm, at least for some of the times in the future.

[Gradient Keeper]

‍♀ ‍♂
Happy Halloween

 

10/31/17 10:43 PM 00z WRF

 

7:00 AM Sunday is looking chilly. Pretty good easterly flow and the low is quite a bit further south now down near Yachats. If only it were 2-3 weeks from now. This is a great pattern for a snow storm for PDX metro.

 

[Deweydog]

 

‍♀ ‍♂

Happy Halloween

 

10/31/17 10:43 PM 00z WRF

 

 

7:00 AM Sunday is looking chilly. Pretty good easterly flow and the low is quite a bit further south now down near Yachats. If only it were 2-3 weeks from now. This is a great pattern for a snow storm for PDX metro.

 

Looks familiar.

 

#lastwinter

[TigerWoodsLibido]

 

‍♀ ‍♂

Happy Halloween

 

10/31/17 10:43 PM 00z WRF

 

7:00 AM Sunday is looking chilly. Pretty good easterly flow and the low is quite a bit further south now down near Yachats. If only it were 2-3 weeks from now. This is a great pattern for a snow storm for PDX metro.

 

 

 

Let's have one sit off the coast like that and undergo bomb cyclogenesis. Put us in a nice and deep deformation band.

[Gradient Keeper]

Looks familiar.

 

#lastwinter

Yeah it sure does. Lows trending further south. Hmmm, 12km Sounding over PDX for Sunday morning shows gusty east winds and temps near freezing. Even colder Monday morning. Overdoing CAA?

 

 

 

[Gradient Keeper]

Let's have one sit off the coast like that and undergo bomb cyclogenesis. Put us in a nice and deep deformation band.

Explosive snowfall rates 2-4" per hour!

[TT-SEA]

Faster timing, less moisture, and further south was a big theme of the models last winter for these sort of setups. Seems like the biases are playing out again. Temperatures will be plenty cold for snow, but now moisture that was initially predicted to hang around into Friday afternoon is finished early Thursday night.

 

I was thinking about that as well... last winter everything seemed to trend south and I was wondering if that theme was going to show up again this weekend.

[Gradient Keeper]

This certainly helps matter! -PNA, -EPO absolutely tanking now into early November

 

[Phil]

Strongest +IOD/+SIOD I've ever seen. Check out those SH SSTAs as well..weakened U-winds for sure.

 

[Gradient Keeper]

Strongest +IOD/+SIOD I've ever seen. Check out those SH SSTAs as well..weakened U-winds for sure.

 

What does this mean or favor to occur?

[snow_wizard]

Strongest +IOD/+SIOD I've ever seen. Check out those SH SSTAs as well..weakened U-winds for sure.

 

 

Could that be the culprit for this acting like a +QBO?

[snow_wizard]

This certainly helps matter! -PNA, -EPO absolutely tanking now into early November

 

 

No doubt that equates to cold.  A minus PNA in combination with any of the following indices being minus is cold for us...AO, NAO, EPO.

[Gradient Keeper]

00z ECMWF brings the low Sunday into around Astoria, Seaside. Too warm for snow in PDX metro, but might be cold enough central Gorge, more likely eastern Gorge. It's okay, it will trend further south with tomorrow's runs.

[TT-SEA]

00z ECMWF brings the low Sunday into around Astoria, Seaside. Too warm for snow in PDX metro, but might be cold enough central Gorge, more likely eastern Gorge. It's okay, it will trend further south with tomorrow's runs.

 

I would almost bet on it. 

[Phil]

Could that be the culprit for this acting like a +QBO?

Could very well be, at least relative to early-season wavetrain climatology. If this holds into midwinter, though..who knows what will happen. The IO/ENSO background states are completely misaligned right now. Haven't seen this conjunction at all since that stretch in the early 1950s..only now we have an expanded warm pool in the WPAC playing on the Hadley Cell there. #HardestForecastEver

[Gradient Keeper]

If the WRF/GFS, CMC don't back off and the ECMWF joins in, by Friday Night/Saturday morning we'll have to begin tracking the progress of cold air pushing south through British Columbia by monitoring the northerly gradients YKA-OMK southward down the Okanagan Valley and OMK-PDT through the Columbia Basin. Nah, I'm not giddy in the slightest.

[snow_wizard]

SEA actually has a shot at their earliest low below 28 ever recorded if Sunday night pans out as cold as the WRF is showing.  Could be close.

[Gradient Keeper]

00z EPS has persistent high pressure/blocking over the North Pacific around the Aleutians, Western Alaska. It wouldn't take much to see a cold pattern setup.

[MikeInEverett]

Latest Cliff Mass update has a pretty deceiving headline... http://cliffmass.blogspot.com/2017/11/snow-expected-over-western-washington.html?utm_source=dlvr.it&utm_medium=twitter

[SilverFallsAndrew]

SEA actually has a shot at their earliest low below 28 ever recorded if Sunday night pans out as cold as the WRF is showing.  Could be close.

 

I would be stunned,.

[HighlandExperience]

High resolution WRF shows snow over east king county.

[Jbolin]

High resolution WRF shows snow over east king county.

Hmm, that'd be something, stark change from the ECMWF that was showing snow over N. Interior and Hood Canal 

[SilverFallsAndrew]

Had a low of 37 this morning. Up to 45 now with clouds. 

[Timmy]

06z brings 2-6” of snow here. Pretty bullish although I think we see a little. And that is based off the low res tropical tidbits map. It shows much more than previous runs.

[SilverFallsAndrew]

06z brings 2-6” of snow here. Pretty bullish although I think we see a little. And that is based off the low res tropical tidbits map. It shows much more than previous runs.

 

That would seem to be a bit overdone. I could see you getting some flakes and maybe a dusting Sunday morning. If you can take advantage of that offshore flow and cold air damming. Down here I think snow stays above 2000', just a little early in the year. 

[Timmy]

That would seem to be a bit overdone. I could see you getting some flakes and maybe a dusting Sunday morning. If you can take advantage of that offshore flow and cold air damming. Down here I think snow stays above 2000', just a little early in the year.

I’m directly West of the gorge And we usually do good in offshore flow set up’s. But I do think 2 to 6 inches is probably over done.

[crf450ish]

There’s an area just north of my house that cuts directly through the Huckleberry mountain range. A road called Cedonia-Addy RD. I’m willing to bet that area sees significant snowfall. #Upslope

 

 

 

 

Area Forecast Discussion

National Weather Service Spokane WA

424 AM PDT Wed Nov 1 2017

 

.SYNOPSIS...

Clear skies tonight will allow temperatures to fall into the 20s

early Tuesday morning. A much cooler, wet and unsettled weather

pattern will develop Wednesday night and will continue through

the weekend bringing heavy snow to the mountains and the northern

valleys Wednesday night through Saturday.

 

&&

 

.DISCUSSION...

Today: A strong west-northwest flow is currently arching over the

region. The Columbia Basin will remain fairly dry for the day. A

cold front traveling the flow through Western MT will press

moisture into the ID Panhandle and Northeastern WA. This is

expected to bring some snow showers up to an inch to this area.

THese areas include Sandpoint and north of the city. Main impacts

will be in the Central Idaho Mountains above 4000ft. Moisture

overshooting the Cascades is expected to bring light snow showers

to that region. Throughout the day, the ridge will slowly flatten

and begin to bring in cooler air.

 

...WINTER STORM WITH HEAVY SNOW TO IMPACT PORTIONS OF THE REGION

THURSDAY THROUGH SATURDAY...

 

Tonight through Thursday: As the flow shifts to more westerly,

snow levels will drop overnight as colder air is pumped into the

region and high impact snow event is expected for northeast WA

and into the central to northern Idaho Panhandle. A low will also

be pushing South along the Washington coast creating some

instability and increasing the moisture in the region. The region

will see precip begin Wednesday night under westerly flow. Models

have backed off on how far south the cold air push will be. This

has kept the snow to mainly the Northern portions of Washington.

The Idaho Panhandle and Cascades can continue to see snow during

this period.

 

* Timing: Snow is expected to begin in the valleys of the Methow

Valley, Okanogan Highlands, Northeast Mtns and Northern

Panhandle by late Wednesday or Thursday morning. Mountain passes

will also see snow beginning at this time. We should then see

rain changing over to snow for the Okanogan Valley, Waterville

Plateau, northern basin and Spokane/Coeur d`Alene corridor as

early as Friday morning (at least for the higher benches above

2,000 feet). These areas further south along the Highway 2

corridor will likely have a harder time accumulating due to

warmer road temperatures.

 

* Snow Amounts: Highest snow accumulations are expected across the

northern mountains and valleys to the Idaho Panhandle. The

mountains will see the potential for a foot to near 2 feet

possible in the Northern Panhandle. Highest accumulations in the

valleys will be in the Okanogan Highlands to the Northern

Panhandle with 6-12 inches possible above 2,500 feet and 2-6

inches at lower elevations of the Northeast Mountains.

 

* Impacts: Confidence is high enough for heavy snow from the

Okanogan Highlands to the Northern Panhandle for a Winter Storm

Watch. We will cover the period when the heaviest snow is

expected, which will be from early Thursday morning through

Friday morning. Expect roads to become snow covered with

treacherous travel likely during this period. Winter highlights

may also be needed in the east slopes of the northern Cascades,

Central Panhandle Mountains and lower elevations surrounding

these mountain zones as the event nears. /JDC

 

Friday through Tuesday...Models have trended much drier for the

Friday and Saturday period. The upper trough axis moves inland

with the mid level frontal boundary moving south and east of the

area. There will still be instability showers to deal with

especially in the mountains, but additional accumulations should

be light. A cooler air mass will be brought into the area courtesy

of the north-northeast winds. Lows will drop into the 20s...with

teens possible in the northern valleys with expected fresh snow

cover. Another wave moves in out of the north Saturday night into

Sunday. The best lift will pass south and west of the area as the

mid level wave tracks from off the WA/OR coast southeast into

Oregon. Still...light precipitation...mainly as snow...is possible

especially along the East Slopes of the Cascades and near the

Oregon border. Monday looks like a dry day as a short wave ridge

moves over the area except for possibly a few lingering snow

showers over the Blue Mountains, Camas Prairie, and Central

Panhandle Mountains. On Tuesday the next upper low drops down out

of the north but takes a more westward route...well off the coast

near 140W. This results in the flow becoming southwesterly over

the area bringing a warming trend towards normal temperatures for

the middle of next week. The best chances for precipitation with

this system should hold off until Wednesday. JW

[MR.SNOWMIZER]

This storm is going to pack a punch at some places for sure. 8-12 inches forecasted near republic and that is alot at one time for there even in the dead of winter. Headed to my property tomorrow to ride it out.

[SilverFallsAndrew]

This storm is going to pack a punch at some places for sure. 8-12 inches forecasted near republic and that is alot at one time for there even in the dead of winter. Headed to my property tomorrow to ride it out.

 

That's awesome! Have fun and stay safe!

[crf450ish]

This storm is going to pack a punch at some places for sure. 8-12 inches forecasted near republic and that is alot at one time for there even in the dead of winter. Headed to my property tomorrow to ride it out.

Hell yeah! Take lots of pics and brag it up on here!

[ShawniganLake]

Faster timing, less moisture, and further south was a big theme of the models last winter for these sort of setups. Seems like the biases are playing out again. Temperatures will be plenty cold for snow, but now moisture that was initially predicted to hang around into Friday afternoon is finished early Thursday night.

Yea the 6z shows less than 0.1” of rain for Victoria in the next week. Models have gutted the first system and the weekend system is continuing to drift south

[TT-SEA]

12z GFS shows varying amounts of snow from Everett to Olympia and up in Whatcom. Still not buying it for the greater Puget Sound I-5 corridor.

 

 

 

12Z GFS did trend north with the system on Saturday night and Sunday.

[SilverFallsAndrew]

12z throws an interesting wrinkle for Sunday night. The airmass behind the departing low would be cold enough for snow here...Would just become a matter of available moisture at that point...

[HighlandExperience]

12z WRF does show snow in the SW interior, mainly with the Saturday night system.

 

Definitely overdone for SW interior. Nice to see though