February 2017 Observations and Model Discussion for the Pacific Northwest

[SilverFallsAndrew]

I think the timing of this system is very helpful for Puget Sound area dwellers, borderline airmass, but almost perfect overnight/early am timing

[HighlandExperience]

I think the timing of this system is very helpful for Puget Sound area dwellers, borderline airmass, but almost perfect overnight/early am timing

It's going to be close. Its to bad it's not slightly colder.

[MossMan]

I have a single flake falling about every 20 seconds currently! 

[snow_wizard]

Still very light snow falling here. Certainly makes tonight look more likely to pan out.

[luvssnow_spokane]

Beautiful Sunny, dry and 41 degree morning here. Just got back from a morning hike. Awesome out!

[SilverFallsAndrew]

Good ensemble improvement for next weekend and the following weekend. The CFS last night showed both events. 

[bainbridgekid]

Surprised to see the NWS calling for up to 4 inches in the EPSL tonight.

Same with the Everett area. Up to 2" for Seattle.

 

I think being at 500 feet is going to make a big difference. I like my chances of seeing an inch or two between about 2 AM and 10 AM.

[The Swamp]

WRF looks good from Pierce county line northward. Starting to feel good about this. Keeping my expectations low though.

Pierce/King line or Pierce/Thurston line north?

[SilverFallsAndrew]

Lots of single digits in SE Oregon last night.

[bainbridgekid]

Just posted this to my personal Facebook. It really is amazing just how borderline our climate is for snow. Makes it unbelievably difficult to forecast accurately 95% of the time. Sometimes I wonder why I put myself out there like this since you can never please everybody, but then I remember it is because I love forecasting weather and I might as well share my passions with the people I care about.

 

As some of you know, I've been talking up snow chances for Sunday morning much of this week. This is still on track. Midnight tonight through about 10 AM tomorrow is the time to watch for lowland snowfall. Best chance is about 4 AM-8 AM. Good timing for snow since it is the coldest time of day!
 

Very tricky forecast because temperatures will be so close to freezing. Generally a 1 degree difference in temperature changes the snow level by about 300 feet, which makes an enormous difference around here. Keep in mind that there is a large amount of uncertainty with these amounts because of the borderline temperatures. 1-2 degrees colder than forecast and even the lowest elevations will see 2-3", 1-2 degrees warmer and nobody below 500 feet will see any accumulations. That said, after analyzing every forecast model this morning, here is my best guess as of now:
 

Bellingham: Trace-1" below 100 feet, 1-2" 100-300 feet, 2-4" above 300 feet elevation.

 

Everett: Trace-1" below 200 feet, 1-2" 200-400 feet, 2-3" above 400 feet.

 

Edmonds/Mountlake Terrace: Trace-1" below 200 feet, 1-2" 200-400 feet, 1-3" above 400 feet.

 

Seattle: Nothing to a trace below 100 feet, Trace to 1" 100-300 feet , 1-2" above 300 feet.

 

Tacoma: Nothing to a trace below 200 feet, Trace to an inch 200-500 feet.

 

East Side: Trace to an inch below 100 feet, 1-2" 100-300 feet, 1-3" above 300 feet.

 

Portland: Cold rain.

 

As you can see, elevation will be the biggest determining factor for snow amounts. You can find your elevation very easily at this site! https://www.freemaptools.com/elevation-finder.htm
 

More updates to come!

[HighlandExperience]

Pierce/King line or Pierce/Thurston line north?

 

Depends on what model you believe. 

[VancouverIslandSouth]

The models are struggling on where the heaviest band on of precipitation will end up in the north but have been pretty consistent in taking a heavy band of precipitation over much of the Puget Sound from Seattle-northward. The GFS has been very consistent on the track of this low and it's a good track for the Puget Sound. I'm hoping for something in this area as well but without a strong supportive high pressure system over the BC interior it's going to be more of a challenge to get snow here than I initially thought. A small different in track could still make a huge difference in totals for some areas and Olympic snow shadowing is an every present risk. The development of a strong secondary low could benefit areas that miss out tonight, but there hasn't yet been any consistency on that feature.

[TT-SEA]

Wow... the 12Z ECMWF is wet for the next 10 days.   

 

This has turned into a very wet winter.

[SilverFallsAndrew]

WRF 48 hour snow total at hour 180.

 

http://www.atmos.washington.edu/wrfrt/data/current_extended/images_d2/or_snow48.180.0000.gif

[bainbridgekid]

Wow... the 12Z ECMWF is wet for the next 10 days.   

 

This has turned into a very wet winter.

How does it look for tonight and tomorrow morning?

[TT-SEA]

Hey Phil... any chance that the western troughing will continue to retrograde?

 

It seems like the models have been rushing this process along and then backing off.      

[bainbridgekid]

High resolution WRF looks relatively widespread:

 

[TT-SEA]

How does it look for tonight and tomorrow morning?

 

Through tomorrow afternoon...

 

[seattleweatherguy]

Trust the ecwf?

[MossMan]

High resolution WRF looks relatively widespread:

 

ww_snow24.36.0000.gif

Purpleish red little bullseye over my house!

[epiceast]

Wow... the 12Z ECMWF is wet for the next 10 days.   

 

This has turned into a very wet winter.

Looking forward to nice temperate atmospheric river day 6-9, turning subtropical towards the end. Could really set Montana up for a great spring ski season.

[VancouverIslandSouth]

The 18z NAM shows generous amounts of precipitation over the next 24 hours. How much falls as rain/mix vs snow will come down to timing and elevation.

 

http://www.tropicaltidbits.com/analysis/models/namconus/2017022518/namconus_apcpn_nwus_9.png

[epiceast]

The 18z NAM shows generous amounts of precipitation over the next 24 hours. How much falls as rain/mix vs snow will come down to timing and elevation.

 

http://www.tropicaltidbits.com/analysis/models/namconus/2017022518/namconus_apcpn_nwus_9.png

One strong cohesive band and it would be all snow.

[umadbro]

Nam is lower with the snow levels in the Willamette valley tomorrow.

[umadbro]

Gfs advertises the same, but a quicker transition to rain than the nam.

[umadbro]

300' snow level. Lol

[SilverFallsAndrew]

Btw this will end up the 5th coldest DJF at PDX

[Guest Dome Buster]

I'm headed up to Welches, OR to stay the night.  Hopefully 1300' puts me in the money overnight.

[Jesse]

I'm headed up to Welches, OR to stay the night.  Hopefully 1300' puts me in the money overnight.

 

I'm not sure how he will feel about that. But I suppose every man has a price!

[SilverFallsAndrew]

I am going with 3" tomorrow and then 1-2" Monday evening...

[Trainwreck]

I have a bet with my dad that he will see 2" by tomorrow night. He lives in Mulino Or at about 800' st the base of the foothills. What do u guys think?

[SilverFallsAndrew]

I have a bet with my dad that he will see 2" by tomorrow night. He lives in Mulino Or at about 800' st the base of the foothills. What do u guys think?

I say 2" is on the high end. Probably around 1"

[SilverFallsAndrew]

42/26 today. Down to 39 now under partly cloudy skies. Nice evening. 

[Guest Sounder]

High resolution WRF looks relatively widespread:

 

ww_snow24.36.0000.gif

You can really see the difference elevation is going to make with this one. I'm definitely glad I don't still live down on the waterfront.

[VancouverIslandSouth]

The low is really zipping down the coast now, it's becoming pretty clear on the Satellite. It looks like snow will be hitting higher elevations south of Bellingham shortly, if it hasn't already started.

[bainbridgekid]

You can really see the difference elevation is going to make with this one. I'm definitely glad I don't still live down on the waterfront.

Absolutely.

 

I could never live on the water here. As beautiful as it is, you'd just get so much less snow. We already get so little that it would be too frustrating for me to constantly get less than everywhere around me.

 

The ultimate example was 2007/08. I got 19" that Winter on Bainbridge at 270 feet and my friend literally 3 miles away right on the beach got zero actual accumulating snowfall the entire Winter. All 19" of mine fell with temperatures between 32.1 and 34.0 degrees.

[snow_wizard]

Nice to see the NWS dropped the snow level to 300 feet. I'm feeling pretty good about our chances. I'm at nearly 400 here. Still looking like a decent chance of something tomorrow night / Monday morning also. Colder air mass at that time.

[snow_wizard]

Looks like a solid shot at snow late next week also as an impressive maritime polar air mass sweeps in over us. Could be March 2012 like...only centered further north.

[The Swamp]

For "my location" here in the swamp I am predicting accumulation of less than a trace.

 

It is currently 46.7 degrees with a shower here and there.

 

Snow?  Laughable.

 

Special Weather Statement by the National Weather Service?  Belly laugh.  Major belly laugh.

[Jesse]

For "my location" here in the swamp I am predicting accumulation of less than a trace.

 

It is currently 46.7 degrees with a shower here and there.

 

Snow?  Laughable.

 

Special Weather Statement by the National Weather Service?  Belly laugh.  Major belly laugh.

 

Those idiots. Don't they realize that the temperature in your garage is never going to change by much this time of year?