February 2014 in the PNW

[MR.SNOWMIZER]

O6z nam is looking better for some snow.

[luterra]

I'm not sure I'm buying the all-day ice idea that both the NWS and KMartin are supporting for the south valley.  Every one of these systems has warmed us a few degrees, from 20 up to 27 yesterday and from 26 up to 31 today.  It's true that we won't have much in the way of southerly flow to scour out the cold air, but we won't have much in the way of northerly flow either.  We only have two degrees to go, and diurnal heating ought to do the trick.  If I had to guess I would say EUG and Corvallis should be above freezing by noon tomorrow.  PDX and areas under gorge influence, or areas farther north, could well see a real ice storm.

[epiceast]

Heavy beer drinking warning just issued for parts of western Washington.

so many hops

[MR.SNOWMIZER]

Even by monday morning we are still about -2 850 and offshore flow with a low right off our coast. Everything looks to be trending south with the warm up by monday.Any further south than what the nam shows monday and we won't warm up.

[BLI snowman]

I'm not sure I'm buying the all-day ice idea that both the NWS and KMartin are supporting for the south valley.  Every one of these systems has warmed us a few degrees, from 20 up to 27 yesterday and from 26 up to 31 today.  It's true that we won't have much in the way of southerly flow to scour out the cold air, but we won't have much in the way of northerly flow either.  We only have two degrees to go, and diurnal heating ought to do the trick.  If I had to guess I would say EUG and Corvallis should be above freezing by noon tomorrow.  PDX and areas under gorge influence, or areas farther north, could well see a real ice storm.

 

Agree with this.

[Perturbance]

I'm not sure I'm buying the all-day ice idea that both the NWS and KMartin are supporting for the south valley.  Every one of these systems has warmed us a few degrees, from 20 up to 27 yesterday and from 26 up to 31 today.  It's true that we won't have much in the way of southerly flow to scour out the cold air, but we won't have much in the way of northerly flow either.  We only have two degrees to go, and diurnal heating ought to do the trick.  If I had to guess I would say EUG and Corvallis should be above freezing by noon tomorrow.  PDX and areas under gorge influence, or areas farther north, could well see a real ice storm.

 

I agree.  I had fairly steady warming of a few degrees Friday evening, finally topping out around 30.5° or so.  Since then it's vacillated between 29° and 30°.  I've had light freezing drizzle throughout the evening, putting a crust atop the snow similar to what I got from the sleet on Thursday.  It doesn't feel like it's going to take much at all to get above freezing.

That being said, I'm glad we're not having the freezing rain (yet, anyway) being experienced in Eugene and places further south and west.  They're already getting power outages as a result, and some decent icicles shown on the 11 o'clock news.

[epiceast]

Even by monday morning we are still about -2 850 and offshore flow with a low right off our coast. Everything looks to be trending south with the warm up by monday.Any further south than what the nam shows monday and we won't warm up.

provide geographical evidence please

[HighlandExperience]

Even by monday morning we are still about -2 850 and offshore flow with a low right off our coast. Everything looks to be trending south with the warm up by monday.Any further south than what the nam shows monday and we won't warm up.

What is the warmest 850 temps with off shore flow that can support snow? -6c

 

If puget sound area can stay chilly Sunday we could get decent snow.

[epiceast]

What is the warmest 850 temps with off shore flow that can support snow? -6c

 

If puget sound area can study chilly Sunday we could get decent snow.

0C

[MR.SNOWMIZER]

provide geographical evidence please

This is 12am monday. Looks like about -2 around seattle and a offshore flow. But notice how just a little further south and we would be in better shape.

[HighlandExperience]

0C

0c at 850 and off shore flow can support snow at sea level? That is interesting.

[MR.SNOWMIZER]

provide geographical evidence please

What is the warmest 850 temps with off shore flow that can support snow? -6c

If puget sound area can stay chilly Sunday we could get decent snow.

I have had almost a foot of snow with a east wind and 0c 850 over here on the hood canal.

[HighlandExperience]

I have had almost a foot of snow with a east wind and 0c 850 over here on the hood canal.

Sunday should be snow than according to the 6z

[Weather101]

I have had almost a foot of snow with a east wind and 0c 850 over here on the hood canal.

We'll let's hope the models trend south

[peregrinator]

Wow, the 06z GFS hammers PDX with almost 0.75" of additional QPF falling before anywhere in the column goes above freezing. It's barely below freezing when the bulk of the precip falls, though, so I wouldn't be sold on an additional 7 inches of snow just yet.

 

Edit: The 00z GGEM shows a similar scenario to the GFS, while the 06z NAM basically says that anything falling after 7AM will be sleet/ZR. The 06z RGEM also marginally supports a sleet profile, rather than snow.

[Perturbed Member]

Wow, the 06z GFS hammers PDX with almost 0.75" of additional QPF falling before anywhere in the column goes above freezing. It's barely below freezing when the bulk of the precip falls, though, so I wouldn't be sold on an additional 7 inches of snow just yet. 

 

Yeah 06z GFS looks pretty wet for PDX. If .75 in QPF actually verified, I think PDX would end up with 7+ inches of snow. We are still offshore flow for quite a while, pretty sure temperatures won't be an issue until a bit later. 

 

Anyone noticed the developing band to the south on the PDX radar?

[Weather101]

Yeah 06z GFS looks pretty wet for PDX. If .75 in QPF actually verified, I think PDX would end up with 7+ inches of snow. We are still offshore flow for quite a while, pretty sure temperatures won't be an issue until a bit later.

 

Anyone noticed the developing band to the south on the PDX radar?

Interesting! Just developed out of nothing

 

22F here clear skies

[peregrinator]

Yeah 06z GFS looks pretty wet for PDX. If .75 in QPF actually verified, I think PDX would end up with 7+ inches of snow. We are still offshore flow for quite a while, pretty sure temperatures won't be an issue until a bit later. 

 

Anyone noticed the developing band to the south on the PDX radar?

 

 

7" of snow would be fantastic, but I'm not so sure that we'll be all snow tomorrow--if the 06z verifies verbatim, then it would be, but there's going to be a strong southerly flow at 800-900mb tomorrow afternoon/evening and it'll be very marginal at best. A shallow warm layer producing mainly sleet is what the NAM and RGEM think will happen, so it's definitely not out of the question.

 

The 06z version isn't out yet, but this plot for the 00z GFS shows it pretty well: http://wxweb.meteostar.com/sample/sample.shtml?text=KPDX . I agree that whatever does fall tomorrow should be frozen though--surface flow will be offshore thanks to the Gorge.

[Gradient Keeper]

Yeah 06z GFS looks pretty wet for PDX. If .75 in QPF actually verified, I think PDX would end up with 7+ inches of snow. We are still offshore flow for quite a while, pretty sure temperatures won't be an issue until a bit later. 

 

Anyone noticed the developing band to the south on the PDX radar?

Yep, I did. That's from the next system and to have precip already developing from it is an ominous sign if you ask me. There is so much more moisture with this next system that extends down to 30 N, 140 W. I just foresee a dangerous Ice storm unfolding Willamette Valley, perhaps 4-8" Snow PDX, then ZR after. This could be a monster of a storm. If PDX transitions even sooner to ZR with PDX-DLS -8 to -10mb do you realize what that would do? I can't imagine an ice storm with 40-50mph east wind. It would be catastrophic to trees, power lines, power poles.

[Gradient Keeper]

2:56 AM Update
Water Vapor Imagery

Check out how extensive the moisture plume is with the next system. It extends all the way back near Hawaii.

http://i61.tinypic.com/vfzciq.png

[Weather101]

Seattle about to get hit by a snow band that formed... Weird tho they have been at 32F all night... Easily can warm up by later today...

 

Maybe not actually.. The band was going north then just turned to the east at the last second... So unlucky for people there! Hopefully it can keep moving north

[Weather101]

Wow. Down to 18 F

[Snow]

The 12Z NAM gives PDX another big snow storm tonight.

 

http://mag.ncep.noaa.gov/data/nam/12/nam_namer_018_1000_500_thick.gif

[Tyler Mode]

Time lapse of the snow in Battle Ground Thursday.  Watch in HD.  Notice the gusty east wind as well, peak of 26 mph that day.

 

[MossMan]

Down to 16 here, another very cold morning!

[Snow]

The 12Z NAM sustained surface winds tonight at 7pm when heavy moisture is falling. Umm, I think we have a problem.....

 

http://oi60.tinypic.com/xfvs5c.jpg

[AnthonyC]

My coworker told me it was snowing when she left her house in Issaquah around 530ish this morning and they had about an inch.

 

Although I'm a bit weary, I do believe that most Puget Sound areas will have received at least an inch by the time this is all said and done.

 

Not as great as it could have been (at least for up here), but at least it's something. Beggars can't be choosers.

 

Yes, I will verify this.  I live in Issaquah at about 750ft and we have about a half an inch.  It's not snowing now, though.  Looks very nice!!

[AnthonyC]

6Z GFS isn't too bad for the SEA area...it actually shows the next batch of precipitation going further north, and would envision areas of the central Puget Sound will get some light snow.  At this point I see most precipitation falling as freezing rain for the PDX area, as the lower levels of the atmosphere have warmed.

 

Beyond that, WA stays on the cooler side of the jet stream with a very active pattern...plenty of mountain snowfall...cooler/showery weather in the lowlands...and then the potential for another colder blast at the end of the month (which is still very much possible given we are in the month of February).

[Prairiedog]

I'd be really surprised if PDX gets a "snowstorm" today but the odds of a bad ice storm is the more probable scenerio.  Perhaps a little snow to start but ZR more likely.  Too much mid level warming already in the valley and numerous reports of light ZR in and around the metro area, albeit some snow flurries over night in places locally.  I picked up another 1/4" after midnight while less than 10 miles away to the south and north there was ZR.  Perhaps with east wind damming up against the coast range it may be thick enough for snow initially in Forest Grove, Vernonia, but on the east side shallower.  I'd love to see more snow but Just don't see a "snow storm".  I'm between Oregon City and Estacada and somewhat protected from the east wind.  Still 26f and a flake or two floating down but Just don't see a big accumulation coming.  I just think from what I'm seeing that it will start as snow locally but fairly quick change over to sleet/ZR.  I see that the NWS is hedging their bets but still lean towards 4-8"  I just don't see it.  That's just how I see it IMHO.

[Snow]

12Z GFS tonight at 7pm, OH WOW! Possible major ice storm tonight for PDX Metro after a good dumping of snow this morning and afternoon.

 

http://mag.ncep.noaa.gov/data/gfs/12/gfs_namer_015_1000_500_thick.gif

[AnthonyC]

SEA looks like it could get some decent accumulation tonight per the 12Z GFS...precipitation is much further north.  And I'm sure (at least initially) it will be cold enough.

[Tyler Mode]

Already turning icy down south.

 

25.8 here and increasing clouds.

[paulb/eugene]

Situation down here in Eugene deteriorating quickly.  Probably raining 0.05/hr, icing here 0.25-0.5in and increasing.

[paulb/eugene]

Power lines now at the "icicle stage" where increased weight of ice is increasingly exponential with time

[SilverFallsAndrew]

I already have a 1/4" of ice up here and 29 degrees. My wife drove to Salem this morning and said it was freezing rain all the way to Salem and then snow once you got there. So the cold air aloft is eroding from the south and east. She said it was 26 in Silverton with ZR, 28 in SLE with snow.

[MR.SNOWMIZER]

I dont think were going to escape the snow this time up here.

[Sometimesdylan]

Got down to about 10 last night. One of the coldest nights up here since November.

[Prairiedog]

Nice snowfall right now last 15 minutes, 26f.  

[TT-SEA]

Yes, I will verify this.  I live in Issaquah at about 750ft and we have about a half an inch.  It's not snowing now, though.  Looks very nice!!

 

 

Are you in the Highlands now??    We are almost neighbors.  

 

Woke up at 4:30 because the dog was barking and the radar looked great at that time.   Nice deformation band over King County.    Only flurries here though due to very dry air.   There was solid green over my area on the radar and there was still nothing but a few flakes fluttering to the ground.

 

WRF shows a chance of snow around midnight tonight for the Seattle area but watching the loop you can see the precip drying up fast as it moves north.

 

The next precip on the WRF arrives tomorrow afternoon and that is almost guaranteed to be rain for the lowlands.   Way too warm aloft.

 

 

SEA only got down to a low of 31 last night!     They are sitting at 32 with a dewpoint of 22 right now.    And the air mass will be moderating quite a bit in the next 24 hours.    That is rain showers tomorrow for SEA

[TT-SEA]

Yes, I will verify this.  I live in Issaquah at about 750ft and we have about a half an inch.  It's not snowing now, though.  Looks very nice!!

 

 

Are you in the Highlands now??    We are almost neighbors.  

 

Woke up at 4:30 because the dog was barking and the radar looked great at that time.   Nice deformation band over King County.    Only flurries here though due to very dry air.   There was solid green over my area on the radar and there was still nothing but a few flakes fluttering to the ground.

 

WRF shows a chance of snow around midnight tonight for the Seattle area but watching the loop you can see the precip drying up fast as it moves north.

 

The next precip on the WRF arrives tomorrow afternoon and that is almost guaranteed to be rain for the lowlands.   Way too warm aloft.

 

 

SEA only got down to a low of 31 last night!     They are sitting at 32 with a dewpoint of 22 right now.    And the air mass will be moderating quite a bit in the next 24 hours.    That is rain showers tomorrow for SEA