February Weather in the Pacific Northwest

[FroYoBro]

I keep hearing how every run has gotten warmer but I’m not seeing it. Fluctuations in snow amounts, precip type and timing aren’t synonymous with “warmer”.

 

Yeah, it seems models have pretty much locked in how cold the air will be in the last 24 hours. Only very tiny changes now on that front. 

[BLI snowman]

Certainly looks like the best shot at a real snow event but temps look suspect. 

 

us_model-en-087-0_modez_2018021612_129_1256_241.png

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That's 1pm, it looks better in the morning. Widespread few inches.

[Jesse]

I agree Jesse. And overall the models from start to finish have improved. Have you seen the GFS ensemble. OMG. Pretty much 10 days where the mean is -5C or lower....Given that I'm not sure we've even verified below -5C at 850mb this winter, that is pretty notable.

It can be irritating to be out and about and see someone say “such and such run has gotten way warmer”, just because a mesoscale map shows less snow over their house. Then when I get a chance to check for myself it is rarely the case.

 

And yeah, overall the next two weeks look like one of the best patterns since the legendary 2008-12 period here.

[Esquimalt]

That's 1pm, it looks better in the morning. Widespread few inches.

Let's hope that's about right.  It would be terrible to let all this cold air go to waste without any snow.  

[Perturbed Member]

I keep hearing how every run has gotten warmer but I’m not seeing it. Fluctuations in snow amounts, precip type and timing aren’t synonymous with “warmer”.

 

I don't mean that we get less cold, I'm more referring to the timing of some of the colder air getting slightly delayed. Things like that do matter for such a borderline setup for most on Sunday.

[SilverFallsAndrew]

It can be irritating to be out and about and see someone say “such and such run has gotten way warmer”, just because a mesoscale map shows less snow over their house. Then when I get a chance to check for myself it is rarely the case.

 

And yeah, overall the next two weeks look like one of the best patterns since the legendary 2008-12 period here.

 

Yeah, any changes in the Sunday-Tuesday period at this point are going to be a couple degrees either way. If anything the models have sped up the timing of the cold air on Sunday. A degree or two warmer at SEA is probably because the models are now anticipating afternoon sunbreaks. The upper level cold actually moves in quite a bit faster now. A couple days ago it wasn't looking like a snow transition would happen here until Sunday afternoon, now the airmass will be cold enough for snow above 1000' in W. Oregon by about 4-5am Sunday morning. 

[MR.SNOWMIZER]

If moss man get's buried I am going to take my snowmobile up there and do wheelies down his road.

[Jesse]

I don't mean that we get less cold, I'm more referring to the timing of some of the colder air getting slightly delayed. Things like that do matter for such a borderline setup for most on Sunday.

I guess it’s important to make that distinction then. To me saying it’s a warmer run means the run is warmer. I’m not getting too hung up on Sunday at this point. The cold air looks to be on track and the details will sort themselves out. It is very hard for the models to accurately pin down precip in these setups. Although I do agree the coast range snow shadow will probably be a factor. Will be a fun day of radar refreshing!

[SilverFallsAndrew]

I don't mean that we get less cold, I'm more referring to the timing of some of the colder air getting slightly delayed. Things like that do matter for such a borderline setup for most on Sunday.

 

The timing of the cold air has moved up 6-12 hours on almost every model over the past few days. 

 

18z Sunday morning from today's 12z run

 

12z run for the same time 2 days ago...

 

[TT-SEA]

I also agree. The 12Z ECMWF is not a warmer run. I did not say that. I said it was a little warmer during the critical period we are watching in the Seattle area on Sunday afternoon. That is all.

[Jesse]

Yeah, any changes in the Sunday-Tuesday period at this point are going to be a couple degrees either way. If anything the models have sped up the timing of the cold air on Sunday. A degree or two warmer at SEA is probably because the models are now anticipating afternoon sunbreaks. The upper level cold actually moves in quite a bit faster now. A couple days ago it wasn't looking like a snow transition would happen here until Sunday afternoon, now the airmass will be cold enough for snow above 1000' in W. Oregon by about 4-5am Sunday morning.

Agree. Overall the models have trended very favorably for cold lately. Both in the short and long term. Moving up the timing of cold air is always a good sign for verification.

[BLI snowman]

Upper level pattern is great at the end of the month. Hopefully we'll be able to tap into some colder air than what the Euro shows.

[MR.SNOWMIZER]

Moisture will be the problem for Seattle and Kitsap area. Flow is Nw so there will be some shadow issues. Our hope in the shadow area is a stronger low development and stronger outflow to help overcome the shadowing. 

[Esquimalt]

Upper level pattern is great at the end of the month. Hopefully we'll be able to tap into some colder air than what the Euro shows.

Yeah it's a wonderful pattern.  The cold air just isn't there.  Almost looks like the polar vortex has been annihilated by that time lol.  

[Perturbed Member]

I guess it’s important to make that distinction then. To me saying it’s a warmer run means the run is warmer. I’m not getting too hung up on Sunday at this point. The cold air looks to be on track and the details will sort themselves out. It is very hard for the models to accurately pin down precip in these setups. Although I do agree the coast range snow shadow will probably be a factor. Will be a fun day of radar refreshing!

 

Agree, those are fair points. 

 

Any accumulating snow we get Sunday I will take as a bonus but I feel much better about the mid-week potential. At the end of the day no matter what happens, this is a lot more interesting than most of this awful winter.

[Front Ranger]

Deep trough after deep trough into the West. God, this pattern looks nice. Been a long time since we've seen the models show troughing this persistent.

[Geos]

Good afd from Seattle NWS. Saying now the outflow will be very strong on Sunday. 

 

Great news.

 

By this wording it sounds like Tim is going to get buried.

 

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 PM PST THIS

EVENING ABOVE 2000 FEET...

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM

PST SUNDAY ABOVE 1000 FEET...

 

* WHAT...Heavy snow expected above 1000 feet. Snow occurring above

2000 feet. Plan on difficult travel conditions. 3 to 7 inches of

snow expected for the rest of today. From late tonight through

Saturday night, 15 to 30 inches of additional snow expected.

 

* WHERE...West Slopes of the Cascade Mountains above 1000 feet,

including Mount Baker, Stevens Pass, Snoqualmie Pass, Mount

Rainier, Crystal Mountain, and White Pass.

[Geos]

Total snow on the ground after the Wednesday event. Not bad

 

us_model-en-087-0_modez_2018021612_135_494_215.png

 

Liking that map the best I think. 

[Perturbed Member]

Detailed PDX and SEA snow maps after Wednesday. 

 

 

 

[Geos]

Certainly looks like the best shot at a real snow event but temps look suspect. 

 

us_model-en-087-0_modez_2018021612_129_1256_241.png

us_model-en_modez_2018021612_129_494_155.png

us_model-en-087-0_modez_2018021612_129_494_488.png

 

Looks like something to be optimistic about. 

[TT-SEA]

Deep trough after deep trough into the West. God, this pattern looks nice. Been a long time since we've seen the models show troughing this persistent.

Hopefully it eventually favors CA and the rest of the West... south of Montana. That can be a nicer pattern for Seattle.

[North_County]

I'm getting buried if that map is to be believed.....

 

Total snow through Sunday at 4 p.m. and the precip is done at this point for WA:

 

 

 

 

Temperatures at 4 p.m. on Sunday... looks warmer than the 00Z run. Still well above freezing in Seattle.

 

[Geos]

Moisture will be the problem for Seattle and Kitsap area. Flow is Nw so there will be some shadow issues. Our hope in the shadow area is a stronger low development and stronger outflow to help overcome the shadowing. 

 

Wondering with a NW flow... will we see a more of a NW to SE orientated CZ band?

[χιόνι (chióni)]

In Texas enjoying temps in 70,s. Will miss the action Sunday but back in Seattle Monday for freeze.

[Geos]

Detailed PDX and SEA snow maps after Wednesday. 

 

us_model-en-087-0_modez_2018021612_135_3955_215.png

 

us_model-en-087-0_modez_2018021612_135_4637_215.png

 

Thinking on the hill I might do slightly better. 

[TT-SEA]

Great news.

 

By this wording it sounds like Tim is going to get buried.

 

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 PM PST THIS

EVENING ABOVE 2000 FEET...

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM

PST SUNDAY ABOVE 1000 FEET...

 

* WHAT...Heavy snow expected above 1000 feet. Snow occurring above

2000 feet. Plan on difficult travel conditions. 3 to 7 inches of

snow expected for the rest of today. From late tonight through

Saturday night, 15 to 30 inches of additional snow expected.

 

* WHERE...West Slopes of the Cascade Mountains above 1000 feet,

including Mount Baker, Stevens Pass, Snoqualmie Pass, Mount

Rainier, Crystal Mountain, and White Pass.

Will not get buried at my house. 1,000 feet is just the start of the heavy snow zone and they are generalizing. The precip will be all rain at my house until Sunday morning.

[Front Ranger]

Hopefully it eventually favors CA and the rest of the West... south of Montana. That can be a nicer pattern for Seattle.

 

I think CA will eventually do alright, as troughs start digging a bit further offshore before moving inland.

 

In the meantime, the next 7-10 days look excellent for a lot of places in the West that have mostly missed out this winter.

[Front Ranger]

Nearly off the charts -PNA for the coming weekend.

 

[TT-SEA]

I think CA will eventually do alright, as troughs start digging a bit further offshore before moving inland.

 

In the meantime, the next 7-10 days look excellent for a lot of places in the West that have mostly missed out this winter.

Looks very dry in CA over the next 10 days... run the precip loop. All the precip is still focused on WA and OR where its not needed compared to other places.

 

Although OR mountains need snow.

[MR.SNOWMIZER]

Nearly off the charts -PNA for the coming weekend.

 

4indices.png

Good God man!!

[MR.SNOWMIZER]

Tim is a badass, posting weather maps at 30000ft.   

[TigerWoodsLibido]

Nearly off the charts -PNA for the coming weekend.

 

4indices.png

 

If only this had happened in Dec or Jan.  One day...

[Geos]

Will not get buried at my house. 1,000 feet is just the start of the heavy snow zone and they are generalizing. The precip will be all rain at my house until Sunday morning.

 

Kind of wondering if you'll hit double digits though. 

[TigerWoodsLibido]

Tim is a badass, posting weather maps at 30000ft. 

 

Hopefully not being charged an exorbitant amount to use their wi-fi.

[Geos]

3km NAM in range now.

 

[seattleweatherguy]

Hopefully not being charged an exorbitant amount to use their wi-fi.

Alaska Airlines charges a lot

[TigerWoodsLibido]

NWS PDX, there were numerous paragraphs about the north Cascades snowfall before this:

 

Now for the million dollar question... Will it snow in the lowlands
Sunday? The answer is probably yes for most, though accumulating snow
is less likely. Snow levels crash from near/above the Cascade Passes
Sat morning to near the valley floor by Sunday morning behind the
front. Beginning Sunday morning, or perhaps even late Sat night, snow
may begin to mix in with the rain down to the valley floor in any
showers. By Sunday afternoon, thermal profiles become favorable for
snow levels near the valley floors despite onshore flow, as 850 mb
temps fall to -8 deg C. However, low-level onshore flow will keep
temps well above freezing during the day Sunday at the lowest
elevations. Though there will probably be a few exceptions due to
heavier showers bringing down the snow level, and these types of
showers will be widespread given the low-level lapse rates, we held
the general snow level at 500 to 1000 feet due to surface heating.
00z suite of guidance trended a bit further west with the broad upper
trough developing over the Pac NW Sunday, with some potential of a
deformation band developing somewhere over the area as the
westernmost of a pair upper low centers tracks southward through
western WA/OR. 00z NAM frontogenesis and omega fields suggest this
potential, with some QPF lingering well behind the front into Sunday
evening. By then, it will be cold enough for accumulating snow down
to the lowest elevations. Also...by Sunday, the air mass over the
coastal waters will be very unstable in the low-levels, almost like a
lake effect snow situation back East. This could surprise coastal
areas with several quick shots of snow as showers move onshore.
Lightning is not out of the question either along the coast, but not
likely enough to mention in the forecast.

The bottom line of this dissertation-length discussion is that while
we have a good idea of the major players affecting our weather
through the upcoming weekend, the details are very complex and it is
likely that there will be changes to the forecast over the coming
days. However, it is very likely that the high Cascades will see
their best snow event in quite some time, and it is likely that just
about everyone in our forecast area sees at least a snowflake or two
in the air by the end of the weekend. The potential is there for
significant impacts to the lowlands, but at this point it does not
look like the ingredients come together for widespread significant
accumulations in the lowlands.    Weagle

[Perturbed Member]

PDX NWS Discussion, this was before the 12z suite

 

 

Now for the million dollar question... Will it snow in the lowlands
Sunday? The answer is probably yes for most, though accumulating snow
is less likely. Snow levels crash from near/above the Cascade Passes
Sat morning to near the valley floor by Sunday morning behind the
front. Beginning Sunday morning, or perhaps even late Sat night, snow
may begin to mix in with the rain down to the valley floor in any
showers. By Sunday afternoon, thermal profiles become favorable for
snow levels near the valley floors despite onshore flow, as 850 mb
temps fall to -8 deg C. However, low-level onshore flow will keep
temps well above freezing during the day Sunday at the lowest
elevations. Though there will probably be a few exceptions due to
heavier showers bringing down the snow level, and these types of
showers will be widespread given the low-level lapse rates, we held
the general snow level at 500 to 1000 feet due to surface heating.
00z suite of guidance trended a bit further west with the broad upper
trough developing over the Pac NW Sunday, with some potential of a
deformation band developing somewhere over the area as the
westernmost of a pair upper low centers tracks southward through
western WA/OR. 00z NAM frontogenesis and omega fields suggest this
potential, with some QPF lingering well behind the front into Sunday
evening. By then, it will be cold enough for accumulating snow down
to the lowest elevations. Also...by Sunday, the air mass over the
coastal waters will be very unstable in the low-levels, almost like a
lake effect snow situation back East. This could surprise coastal
areas with several quick shots of snow as showers move onshore.
Lightning is not out of the question either along the coast, but not
likely enough to mention in the forecast.

The bottom line of this dissertation-length discussion is that while
we have a good idea of the major players affecting our weather
through the upcoming weekend, the details are very complex and it is
likely that there will be changes to the forecast over the coming
days. However, it is very likely that the high Cascades will see
their best snow event in quite some time, and it is likely that just
about everyone in our forecast area sees at least a snowflake or two
in the air by the end of the weekend. The potential is there for
significant impacts to the lowlands, but at this point it does not
look like the ingredients come together for widespread significant
accumulations in the lowlands.Weagle

[FroYoBro]

I'm thinking about posting the Portland NWS discussion. Should I?

[Jesse]

I'm thinking about posting the Portland NWS discussion. Should I?

You should quote the other two then post it.