February 2017 Observations and Model Discussion for the Pacific Northwest

[VancouverIslandSouth]

We just drove down to North Bend for some game-time supplies at Safeway.   The snow level is just barely below our elevation.   As soon as you start going down the hill it turns to rain and at about 700 feet the ground is bare.   

 

Drizzle in North Bend.

 

The Fraser Valley outflow seems to be dominating the Snoqualmie outflow this time around. There's a chance low elevations in the Fraser Valley end up with higher totals than your area; I can't imagine that happens very often.

[bainbridgekid]

Sumas sure looks buried. It's been an amazing Winter up there.

 

 

 

[bainbridgekid]

The Fraser Valley outflow seems to be dominating the Snoqualmie outflow this time around. There's a chance low elevations in the Fraser Valley end up with higher totals than your area; I can't imagine that happens very often.

That actually happens pretty frequently. Anytime the cold air gets hung up around Whatcom County.

 

Hard to imagine Tim getting less than 6-8" with this storm though since he already has a few inches and it's just getting started.

[MossMan]

18z 3km NAM shows a period of very heavy snow for the EPSL this evening.

 

get_orig_img.gif

Shows rain over my area while snow most everywhere else...Hahahaha...

[Arctic Front]

Sumas sure looks buried. It's been an amazing Winter up there.

 

009vc09781.jpg

Lynden got hit hard last night as well, have a friend up there with about a foot of snow and no power

[Perturbed Member]

33.8

 

It's obvious with the number of changeovers that I've had that the warm air is winning out just ESE of here, so I don't really see a scenario where Portland/Vancouver get accumulations aside from maybe early morning. I also don't see my temp getting any lower, so it looks like I'll be set on 34 degree rain/snow stuff most of the storm. Have had a slushy trace thus far.

 

 

Yeah I'm sitting at 36F with wet flakes mixing in for 2 hours now despite heavy precip. Pretty obvious that the WRF solution and other similar ones will not be verifying. Might get some lighter accumulations as the front begins to pull east. I guess there is a reason why we've had so few snowstorms workout with these kind  of setups. Not much margin for error. 

[Tenochtitlan]

I was going to go to Vancouver today (ironically to try curling for the first time) but the roads are too bad by the border, so I'm going to go with a couple of friends and see if we can get to Lynden or Ferndale instead and check out the snow there.

[FroYoBro]

33.8

 

It's obvious with the number of changeovers that I've had that the warm air is winning out just ESE of here, so I don't really see a scenario where Portland/Vancouver get accumulations aside from maybe early morning. I also don't see my temp getting any lower, so it looks like I'll be set on 34 degree rain/snow stuff most of the storm. Have had a slushy trace thus far.

I'd be very happy with just seeing some wet snow in the air tonight here. 

[Jesse]

Yeah I'm sitting at 36F with wet flakes mixing in for 2 hours now despite heavy precip. Pretty obvious that the WRF solution and other similar ones will not be verifying. Might get some lighter accumulations as the front begins to pull east. I guess there is a reason why we've had so few snowstorms workout with these kind  of setups. Not much margin for error. 

 

I was always under the impression that the big stuff wasn't expected until later this evening anyway.

[VancouverIslandSouth]

The two lows are pretty clear on the satellite now, it's obvious which one is packing the most punch:

 

http://images.intellicast.com/WxImages/Satellite/hipacsat.gif

[luvssnow_spokane]

I was always under the impression that the big stuff wasn't expected until later this evening anyway.

Correct  Snowing pretty hard here now. Not really sticking much yet. 

[luvssnow_spokane]

I have to say... Even though the snow is not accumulating, this is longest I have seen the snow fall in almost 5 years here.

[bainbridgekid]

Correct  Snowing pretty hard here now. Not really sticking much yet. 

You are going to be in a good spot tonight. 

 

Once it starts sticking, it should pile up fast. Probably 4-6" there by tomorrow morning.

[BLI snowman]

I was always under the impression that the big stuff wasn't expected until later this evening anyway.

 

For the places that avoid the warm tongue, snowfall rates will be heaviest later on. But everything points to the 850mb/925mb warm layer being a bit more significant by this evening down here. 

[bainbridgekid]

First clear flakes starting to mix in here now.

 

Still about 90% light rain, 10% wet snow.

[dairyd]

I was going to go to Vancouver today (ironically to try curling for the first time) but the roads are too bad by the border, so I'm going to go with a couple of friends and see if we can get to Lynden or Ferndale instead and check out the snow there.

 

Please remember there is up to 1" of ice under the snow.  We can't even keep 4WD trucks on the road this morning.  Cars are sliding off the road all over up here. If it doesn't look plowed/salt/sanded it's best to stay off.

[Perturbed Member]

I was always under the impression that the big stuff wasn't expected until later this evening anyway.

 

Some of the models showed a changeover earlier in the afternoon. WRF showed it at around 1-2 PM. Earlier runs of the HRRR and 3km NAM showed a rain to snow to rain and back to snow in the evening scenario. Obviously all wrong.  

 

Mark Nelsen is sticking to his trace-3 in after 7 PM forecast.

[Perturbed Member]

For the places that avoid the warm tongue, snowfall rates will be heaviest later on. But everything points to the 850mb/925mb warm layer being a bit more significant by this evening down here. 

 

The HRRR wanting to move things northward again supports that theory too. 18z NAM showed the same as well. The setup was already marginal and I think that little extra movement north is the dagger for most of the areas south. 

 

Amazing how much the models have been going back and forth on this. 

[Front Ranger]

Looking at web cams, looks like sticking snow starts around far south Tacoma, just south of American Lake near JBLM.

[Perturbed Member]

850mb temps are cool enough but this warm layer at 925 is being a pest. 

 

http://www.spc.noaa.gov/exper/mesoanalysis/s11/925mb/925mb.gif?1486329521256

[MossMan]

Mesoscale analysis shows 850s around -5c and 925s around -1c. Following fairly closely with the models so far. Fraser Valley gradient is sitting around -9mb, want to see that continue to increase as we get into the afternoon.

 

Looks like most surface temps are around freezing or a degree or two higher in the South Sound, mid to upper 30s King County and North.

Is it the evaporated cooling and precip rates causing the south sound to be so much cooler?

[VancouverIslandSouth]

Nice day around Abbotsford:

 

http://images.drivebc.ca/bchighwaycam/pub/cameras/278.jpg

 

 

http://images.drivebc.ca/bchighwaycam/pub/cameras/463.jpg

[Front Ranger]

Is it the evaporated cooling and precip rates causing the south sound to be so much cooler?

 

Yes.

[luvssnow_spokane]

850mb temps are cool enough but this warm layer at 925 is being a pest. 

 

http://www.spc.noaa.gov/exper/mesoanalysis/s11/925mb/925mb.gif?1486329521256

Heavier precipitation rates should fix that.

[BLI snowman]

The HRRR wanting to move things northward again supports that theory too. 18z NAM showed the same as well. The setup was already marginal and I think that little extra movement north is the dagger for most of the areas south. 

 

Amazing how much the models have been going back and forth on this. 

 

I suspect the 18z GFS will follow suit, probably be a bit further north.

[bainbridgekid]

Is it the evaporated cooling and precip rates causing the south sound to be so much cooler?

Evaporative cooling isn't actually much of a factor because the air was already so humid before this system.

 

It's more dynamic cooling caused by moderate to heavy precip rates. Melting snow takes energy and cools the column down and the more rain there is to melt, the more cooling occurs.

[Timmy]

Snowing hard at rockaway beach

[Guest Dome Buster]

The latching on to each successive model is such a joke on this forum. North, south, north, south. It really is quite laughable.

[Guest Dome Buster]

I know right? These peasants and their weather models... It's not like we are on a weather forum for God's sake! The horror!

Well. We may as well call it a cherry picking forum. Pick whichever one shows snow for you and call it gospel. LOL.

 

Just listen to Mark. He already said the goods don't happen until 7 PM, especially down here. Just be happy it is mixing already.

[Jesse]

The latching on to each successive model is such a joke on this forum. North, south, north, south. It really is quite laughable.

I find the fact that every prediction you have made since you started posting here has been dead wrong even more laughable.

[TT-SEA]

Evaporative cooling isn't actually much of a factor because the air was already so humid before this system.

 

It's more dynamic cooling caused by moderate to heavy precip rates. Melting snow takes energy and cools the column down and the more rain there is to melt, the more cooling occurs.

Excellent description.

[Front Ranger]

Well. We may as well call it a cherry picking forum. Pick whichever one shows snow for you and call it gospel. LOL.

 

Just listen to Mark. He already said the goods don't happen until 7 PM, especially down here. Just be happy it is mixing already.

 

Still sticking with no snow for the Puget Sound?

[Guest Sounder]

All this "the models have been so inconsistent!!!" hand wringing with this is pretty unwarranted. It just so happens that this is a set up where a small jog to the north or south means a world of difference to the majority of posters here. South and Seattle gets no precip. North and Portland is too warm. But think about this from the perspective of someone in Chehalis. Basically every run of every model for the last 4-5 days has shown them getting buried. If anything, the models have handled this event quite well so far. Just because from our individual perspective minor changes mean a big difference doesn't mean that the models have been way off.

[Front Ranger]

Evaporative cooling isn't actually much of a factor because the air was already so humid before this system.

 

It's more dynamic cooling caused by moderate to heavy precip rates. Melting snow takes energy and cools the column down and the more rain there is to melt, the more cooling occurs.

 

But to give a shorter, less complex answer...yes, it's cooler in the south sound right now due to precip rates. 

[Blizzard777]

The latching on to each successive model is such a joke on this forum. North, south, north, south. It really is quite laughable.

Tennis ball match between Seattle and Portland, ball will hit net in middle fall to ground

[Front Ranger]

All this "the models have been so inconsistent!!!" hang wringing with this is pretty unwarranted. It just so happens that this is a set up where a small jog to the north or south means a world of difference to the majority of posters here. South and Seattle gets no precip. North and Portland is too warm. But think about this from the perspective of someone in Chehalis. Basically every run of every model for the last 4-5 days has shown them getting buried. If anything, the models have handled this event quite well so far. Just because from our individual perspective minor changes mean a big difference doesn't mean that the models have been way off.

 

Still too soon to call, but the Euro/GEM have definitely led the way.

 

Go globalism!

[bainbridgekid]

18z is just about the snowiest run yet for Puget Sound.

 

Spits out 8" for Seattle and there's a band of about a foot in SE King County and just East of Tacoma.

 

 

It also spits out 2" for Seattle by 4 PM today though, so I would definitely cut these totals down some.

[Jesse]

Still too soon to call, but the Euro/GEM have definitely led the way.

 

Go globalism!

 

12z Euro and GEM showed a heart stopping southward shift this morning which hasn't really panned out.

[Guest Sounder]

It also spits out 2" for Seattle by 4 PM today though, so I would definitely cut these totals down some.

 

There's still time god D**n it!!!!!!!!!!!

[Guest Dome Buster]

12z Euro and GEM showed a heart stopping southward shift this morning which hasn't really panned out.

Hasn't happened yet. And the low is south.......off the coast. 12z is actually doing real well with things.