November 2017 PNW Discussion Thread

[TigerWoodsLibido]

Arctic blocking returns on the latest EPS weeklies, starting just after Thanksgiving, and continuing into at least the third of December.

How far south?

[stuffradio]

I got 0 snow, not even a dusting.

[Jesse]

47 degrees and a fairly steady set of showers here. Nothing unusual for this time of year. Maybe a degree or 2 below normal. GFS doesn't show us hitting the freezing point in its latest run.

This is an impressively cool trough for this time of year, even if we don’t get snow down here. It’s really, really early to expect snow down here.

[Jesse]

How far south?

Looks like the arctic front is probably going to stall in Yamhill County.

[Geos]

FWIW, 00z NAM shows a narrow PSCZ-type signature for tomorrow morning and into the afternoon. If it were to occur, and NW flow aloft does aide in it's development, that might be the only way the lowlands see snow with the otherwise marginal conditions.

 

After living here all my life I've learned to never underestimate the power of a strong PSCZ. 

 

 

I like your optimism.

 

3km NAM showing heavy snow in NW King County right before rush hour.

 

 

[VancouverIslandSouth]

Just got home to Shawnigan. Snowing here and the ground is white. Snow level was about 350ft. Sticking snow 450ft.

 

Still just a cold rain here, but things seem to be moving slower than modeled. There's ton of moisture and the outflow is creeping in rather than racing in so it could bode better for tonight. The drop in temperature was pretty dramatic this afternoon, from nearly 50F and sunny down to 38F in about an hour, but temperatures have remained just a little to warm for snow to mix in at this elevation. Currently sitting at 37F.

[snow_wizard]

The NWS is going pretty bullish with the S word both tonight / tomorrow morning and on Sunday.  Truly extraordinary setup for this time of year.

[VancouverIslandSouth]

Another bust for the WRF, last night's run had things completely dry over most northern areas by this time. The current radar says otherwise. It seems like the 3k NAM has done a pretty good job at handling this so far.

 

[TT-SEA]

BLI is at 35 with a dewpoint of 30... if any precip reaches them overnight it will be snow.  

[snow_wizard]

Another very interesting thing to remember is the late September, mid October, and now this trough all would be sure snow producers from late Nov through mid Feb.  Knowing how the atmosphere normally has a "memory" within a given season that is reason for optimism.

[TigerWoodsLibido]

Looks like the arctic front is probably going to stall in Yamhill County.

How rude of it

[Chewbacca Defense]

Getting some flurries here in Bellingham (just north of Lake Whatcom), and its at 34 degrees here at my house.

 

Watching the Sounders match and they just had thunder and lightning

[snow_wizard]

Looks like the NAM MM5 is too slow bringing the wind shift southward.  The wind has already switched in places well south of where that model indicated for this early.

[High Desert Mat!]

Another very interesting thing to remember is the late September, mid October, and now this trough all would be sure snow producers from late Nov through mid Feb. Knowing how the atmosphere normally has a "memory" within a given season that is reason for optimism.

That's a weird thing to say Jim. I love your optimism but the memory thing is far fetched. Maybe it happens but if it does it's not because of the memory. It may be because of the dark side of the moon or the bright side of the sun. Either way I think this winter will be a poor mans version of last winter.

[Parksvillewx]

Moderately snowing here still. Temp stuck at 32F as it has been since about 1pm. About 1" of slop accumulated so far. 

The roads are going to be a joke in the AM if it gets colder overnight.

[Phil]

Also a fairly significant cluster of EPS (weekly) members with a large ridge centered over Alaska heading into December.

 

About 2/3rds of the members are cold across the west overall with blocking over Alaska and the Arctic, while 1/3rd are warmer than normal with an Alaska Low/Polar Vortex pattern. This is a minority solution, though.

[TT-SEA]

That's a weird thing to say Jim. I love your optimism but the memory thing is far fetched. Maybe it happens but if it does it's not because of the memory. It may be because of the dark side of the moon or the bright side of the sun. Either way I think this winter will be a poor mans version of last winter.

 

I actually think patterns do get stuck in a rut and repeat.   

[BLI snowman]

That's a weird thing to say Jim. I love your optimism but the memory thing is far fetched. Maybe it happens but if it does it's not because of the memory. It may be because of the dark side of the moon or the bright side of the sun. Either way I think this winter will be a poor mans version of last winter.

 

Poor man's version of last winter isn't exactly bad.

[Jesse]

That's a weird thing to say Jim. I love your optimism but the memory thing is far fetched. Maybe it happens but if it does it's not because of the memory. It may be because of the dark side of the moon or the bright side of the sun. Either way I think this winter will be a poor mans version of last winter.

Certain 500mb patterns repeating over the course of a season is a real thing. There are many examples.

 

Not to say that these well, but it isn’t like Jim is totally out of left field here.

[Deweydog]

I actually think patterns do get stuck in a rut and repeat.

Definitely, but extrapolating in such a manner inter-seasonally is pretty hazy leap of faith.

[VancouverIslandSouth]

I actually think patterns do get stuck in a rut and repeat.   

 

Yep, like the great Victorian drought of 2017. 

[Gradient Keeper]

Certain 500mb patterns repeating over the course of a season is a real thing. There are many examples.

 

Not to say that these well, but it isn’t like Jim is totally out of left field here.

Agreed.

[VancouverIslandSouth]

Finally starting to see the odd batch of snowflakes mixing in with the rain. Things do seem to be moving slower than original forecast. I was expecting the outflow to start dominating at this point, but so far it only seems to be present near the surface. 

[BLI snowman]

Finally starting to see the odd batch of snowflakes mixing in with the rain. Things do seem to be moving slower than original forecast. I was expecting the outflow to start dominating at this point, but so far it only seems to be present near the surface. 

 

 

Residual drought impacts?

[VancouverIslandSouth]

Residual drought impacts?

 

The very low humidity in the Victoria area has absorbed an abnormal amount of humidity weakening the surface low and dampening the outflow.

[VancouverIslandSouth]

It's completely switched over to snow now with the temperature approaching 34F. A bit more of this and we might even see something stick. Regardless, it's the earliest I've ever seen snow in Victoria.

[Jesse]

It's completely switched over to snow now with the temperature approaching 34F. A bit more of this and we might even see something stick. Regardless, it's the earliest I've ever seen snow in Victoria.

Pretty crazy.

[TT-SEA]

Snowing in Bellingham... watch streaming live here:

 

http://barkleyvillage.com/web-cameras/

[luminen]

Snowed for quite a few hours in Burnaby today but no accumulation. Here in North Vancouver it's dry right now. Let's see if we get any accumulation throughout the night.

 

It wasn't long ago we were sweating buckets.

[HighlandExperience]

00z WRF mirrors the NAM - has a PSCZ forming in King County early tomorrow morning and dropping south to Pierce thereafter. Only about an inch most places, if that, but I'll take it!

That would be a special way to kick off the season.

[snow_wizard]

That's a weird thing to say Jim. I love your optimism but the memory thing is far fetched. Maybe it happens but if it does it's not because of the memory. It may be because of the dark side of the moon or the bright side of the sun. Either way I think this winter will be a poor mans version of last winter.

 

The memory thing is actually pretty well established.

[Geos]

00z WRF mirrors the NAM - has a PSCZ forming in King County early tomorrow morning and dropping south to Pierce thereafter. Only about an inch most places, if that, but I'll take it! 

 

I'll take any snow on November 3rd!

 

Down to 40.

[HighlandExperience]

00z WRF mirrors the NAM - has a PSCZ forming in King County early tomorrow morning and dropping south to Pierce thereafter. Only about an inch most places, if that, but I'll take it!

Not bad going into tommorow morning

[snow_wizard]

00z WRF mirrors the NAM - has a PSCZ forming in King County early tomorrow morning and dropping south to Pierce thereafter. Only about an inch most places, if that, but I'll take it! 

 

It pretty impressive how the NAM and GFS mesoscale models agree on the area between Seattle and Tacoma being the winner.  On top of that the 12z and 0z have almost exactly the same placement.

[VancouverIslandSouth]

Not bad going into tommorow morning

 

Yikes, that shows 3" here, the last few runs showed virtually nothing; but then again it's the WRF. It's really dumping now, there are massive flakes and it's finally started to accumulate. I'd be happy with any accumulation at this point.

[snow_wizard]

I can't even imagine getting two decent snows in a two day period this early in the season.  Could happen though with the track of Sunday's low being utterly perfect for the Puget Sound region.

[Front Ranger]

Certainly some borderline historic stuff being shown. Probably wouldn't believe it except for what's already happened today/tonight. Very impressive.

[HighlandExperience]

I can't even imagine getting two decent snows in a two day period this early in the season. Could happen though with the track of Sunday's low being utterly perfect for the Puget Sound region.

The euro will knock us back to reality

[wx_statman]

33 with a dp of 25 in Ferndale with Fraser outflow. This is a legitimately cold airmass entering Whatcom Co.

[Front Ranger]

 

Little fun fact for you all:

 

 

If Seattle only reaches 44 degrees as forecast tomorrow, that would tie a record low maximum for the date set in 1974. #wawx

— NWS Seattle (@NWSSeattle) November 3, 2017

 

 

Doubt it happens, but 41 from 10/31/84 is the benchmark high to beat.

 

What's insane is how the record low max's go from 42 on 11/10 to 21 on 11/12 (1955). Every time I look at the numbers from that event it's just mind-boggling.