February 2019 Weather in the Pacific Northwest - Part 1

[snow_wizard]

A more recent analog to the coming pattern IMO would be Feb 1990.  This kind of has the same feel.

[TT-SEA]

Worth noting is that the actual upper level features weren’t shifted north. Just fickle deformation zone placement.

Good point.

[snow_wizard]

Worth noting is that the actual upper level features weren’t shifted north. Just fickle deformation zone placement.

 

Models often have big problems pegging deformation band precip.  This should be interesting.  The NE quadrant of the ULL often does well in these cases.  Right now Seattle falls into that zone.

[Frontal Snowsquall]

We need to make a forecast contest! So everybody doesn't think I'm joking with what I'm thinking at the moment.....

[TT-SEA]

GFS MOS shows 44 and partly cloudy for SEA on Monday.

 

Comically wrong in this situation.

[snow_wizard]

An interesting thing about what I consider the two best matches to the coming pattern (Feb 1891 and 1990) is both of those winters sucked arse before February.

[Perturbed Member]

I think he's being way too conservative.

 

Basically he doesn't buy the cold coming through the gorge that quickly and nor is he counting on the deformation band. Obviously PDX metro will do much better if these end up being a factor.

 

 

"Two big caveats:

1. The NAM and WRF-GFS are bringing cold arctic air south through Eastern Washington Sunday night and Monday morning.  They push it through the Gorge on cold easterly wind and it’s here at sunrise Monday.  I think most likely they are overdoing the cold air.  That would lead to a more “frozen/east wind” sort of setup that would impact us much more.  The more reliable Euro and Canadian models don’t show that, keeping us in a “scattered snow shower” setup.

Notice the WRF-GFS showing a classic snow-storm setup with surface low pressure offshore and at least 8 millibars of very cold east wind blowing through the Gorge

 

2) At various times the past 48 hours models have been trying to show a more concentrated band of heavier precipitation Monday morning/midday right over us.  That could produce a more widespread wet/heavy snowfall.  At this point no model is showing that so I’ll discount that as well.

I’ll be up early Sunday morning in full weather mode so I should have a more extensive blog post with some “final” forecast numbers by late morning/midday."

 

 

[snow_wizard]

We need to make a forecast contest! So everybody doesn't think I'm joking with what I'm thinking at the moment.....

 

I go with 2 inches for your area.

[snow_wizard]

 

Basically he doesn't buy the cold coming through the gorge that quickly and nor is he counting on the deformation band. Obviously PDX metro will do much better if these end up being a factor.

 

 

"Two big caveats:

1. The NAM and WRF-GFS are bringing cold arctic air south through Eastern Washington Sunday night and Monday morning.  They push it through the Gorge on cold easterly wind and it’s here at sunrise Monday.  I think most likely they are overdoing the cold air.  That would lead to a more “frozen/east wind” sort of setup that would impact us much more.  The more reliable Euro and Canadian models don’t show that, keeping us in a “scattered snow shower” setup.

Notice the WRF-GFS showing a classic snow-storm setup with surface low pressure offshore and at least 8 millibars of very cold east wind blowing through the Gorge

 

2) At various times the past 48 hours models have been trying to show a more concentrated band of heavier precipitation Monday morning/midday right over us.  That could produce a more widespread wet/heavy snowfall.  At this point no model is showing that so I’ll discount that as well.

I’ll be up early Sunday morning in full weather mode so I should have a more extensive blog post with some “final” forecast numbers by late morning/midday."

 

 

 

 

You think the GEM is better than the GFS?  Not saying your wrong, but I'm far from sure of that.

[Jesse]

Been awhile since Dewey has popped on and made a comment subtly implying he thinks we’re all idiots. I find it grounding sometimes.

[GHweatherChris]

Been awhile since Dewey has popped on and made a comment subtly implying he thinks we’re all idiots. I find it grounding sometimes.

That crossed my mind too, feels like we are all getting away with something we shouldn't be this morning.

[snow_wizard]

Been awhile since Dewey has popped on and made a comment subtly implying he thinks we’re all idiots. I find it grounding sometimes.

 

He's just pretending to not be one himself.

[TT-SEA]

Worth noting is that the actual upper level features weren’t shifted north. Just fickle deformation zone placement.

 

 

Actually did change slightly.   Here is the comparison at 4 a.m. on Monday:

 

00Z run...

 

 

 

And the 12Z run...

 

 

 

Enough to change the results in the Seattle area dramatically.  

[Jesse]

 

Basically he doesn't buy the cold coming through the gorge that quickly and nor is he counting on the deformation band. Obviously PDX metro will do much better if these end up being a factor.

 

 

"Two big caveats:

[*]The NAM and WRF-GFS are bringing cold arctic air south through Eastern Washington Sunday night and Monday morning. They push it through the Gorge on cold easterly wind and it’s here at sunrise Monday. I think most likely they are overdoing the cold air. That would lead to a more “frozen/east wind” sort of setup that would impact us much more. The more reliable Euro and Canadian models don’t show that, keeping us in a “scattered snow shower” setup.

 

 

Weird he would mention the Euro not showing that since that’s precisely what it showed last night. Maybe he posted before the run. Although granted the 12z dialed things back a bit.

[snow_wizard]

The Euro shows no sign of the pattern warming up anytime soon at day 10.  This could be one for the ages, especially if we get a top tier blast in the mix at some point.

[Brennan]

wind switched in Lytton, BC

time_chart.cgi.png

Can u send me the link to the site with this graphic for wind? Thanks

[Esquimalt]

The Euro shows no sign of the pattern warming up anytime soon at day 10. This could be one for the ages, especially if we get a top tier blast in the mix at some point.

The ridge looks like it’s pushijg towards the shore at hour 240 thou. Don’t like that

[Frontal Snowsquall]

I go with 2 inches for your area.

 

I would honestly be disappointed with that but the good thing though is we will likely have lots of cold and snow chances further down the line.

[GHweatherChris]

[snow_wizard]

That crossed my mind too, feels like we are all getting away with something we shouldn't be this morning.

 

True.  I need to be doing other things.

[snow_wizard]

Can u send me the link to the site with this graphic for wind? Thanks

 

Go the Seattle National Weather Service site and click on the observations link.  There will be a map that shows the current conditions at many weather stations.  Invaluable for tracking these things.

[TT-SEA]

I would honestly be disappointed with that but the good thing though is we will likely have lots of cold and snow chances further down the line.

I think the big winner will be whoever is under that deformation band on Sunday night and Monday morning. It's not that wide and it will not be both Seattle and Portland. It could be neither of them if it's in between. But my guess is Seattle. Our gain will be Portland's loss.

[Jesse]

Actually did change slightly.   Here is the comparison at 4 a.m. on Monday:

 

00Z run...

 

 

And the 12Z run...

 

 

Enough to change the results in the Seattle area dramatically.  

 

That's pretty d**n slight. I would say the tilt of the trough has changed more than any meaningful latitudinal movement.

[GHweatherChris]

True. I need to be doing other things.

I am currently making homemade Chicken Tortilla Soup for lunch to occupy me.

[Frontal Snowsquall]

 

Basically he doesn't buy the cold coming through the gorge that quickly and nor is he counting on the deformation band. Obviously PDX metro will do much better if these end up being a factor.

 

 

"Two big caveats:

1. The NAM and WRF-GFS are bringing cold arctic air south through Eastern Washington Sunday night and Monday morning.  They push it through the Gorge on cold easterly wind and it’s here at sunrise Monday.  I think most likely they are overdoing the cold air.  That would lead to a more “frozen/east wind” sort of setup that would impact us much more.  The more reliable Euro and Canadian models don’t show that, keeping us in a “scattered snow shower” setup.

Notice the WRF-GFS showing a classic snow-storm setup with surface low pressure offshore and at least 8 millibars of very cold east wind blowing through the Gorge

 

2) At various times the past 48 hours models have been trying to show a more concentrated band of heavier precipitation Monday morning/midday right over us.  That could produce a more widespread wet/heavy snowfall.  At this point no model is showing that so I’ll discount that as well.

I’ll be up early Sunday morning in full weather mode so I should have a more extensive blog post with some “final” forecast numbers by late morning/midday."

 

 

 

 

The WRF-GFS is the reason why I'm really bullish right now. If it didn't show what it has been showing then yeah I'd only call for 1"-2" tops. I've just seen over and over again the models fail to take into account the cold pool and cold Gorge east winds. I just can't ignore it at the moment.

[Jesse]

True.  I need to be doing other things.

 

This upcoming pattern has been distraction city for me the last couple days.

[TT-SEA]

That's pretty d**n slight. I would say the tilt of the trough has changed more than any meaningful latitudinal movement.

I agree... tilt is the big difference. And even that is not a huge change.

[Jesse]

I agree... tilt is the big difference. And even that is not a huge change.

 

DZs be fickle beezys.

[snow_wizard]

This upcoming pattern has been distraction city for me the last couple days.

 

We COULD be looking at history in the making so it is distracting!

[Frontal Snowsquall]

I think the big winner will be whoever is under that deformation band on Sunday night and Monday morning. It's not that wide and it will not be both Seattle and Portland. It could be neither of them if it's in between. But my guess is Seattle. Our gain will be Portland's loss.

 

Yeah, the lucky soul(s) who get to be under that deformation band will score. Hopefully it will be one of us and doesn't set up around Centralia. Then everybody would get screwed.

[snow_wizard]

Link for current obs map.

 

https://www.wrh.noaa.gov/map/?obs=true&wfo=sew

[Jesse]

The ridge looks like it’s pushijg towards the shore at hour 240 thou. Don’t like that

 

That would be a pretty cold pattern at the surface. And the ridge offshore looks like it is re-configuring itself for another shortwave trough to drop down the leeward side. Got my extrapolation boots on for that one!

[BLI snowman]

I would honestly be disappointed with that but the good thing though is we will likely have lots of cold and snow chances further down the line.

 

That is 2" more than we've seen all winter. Keeping expectations in check is a pretty critical part of not losing your sh*t here. This isn't a favorable setup for a widespread huge snowstorm.

[Perturbed Member]

Weird he would mention the Euro not showing that since that’s precisely what it showed last night. Maybe he posted before the run. Although granted the 12z dialed things back a bit.

 

Yeah, probably just typical conservative Mark. 

 

I do wonder if the mesoscale models should be more trusted in modeling the movement of the low level cold through the gorge now that we are in the 48 hr window. WRF and 3km NAM quite a bit more aggressive in getting that cold offshore flow going for many runs now. Will be interesting to see how this turns out. 

 

 

[MossMan]

GFS MOS shows 44 and partly cloudy for SEA on Monday.

 

Comically wrong in this situation.

That’s what a 13 degree difference than the Euro?

[BLI snowman]

498 thickness line was making a bee line for SW WA at this time 30 years ago

 

http://mp1.met.psu.edu/~fxg1/NARR/1989/us0202.php

[snow_wizard]

Down to 3F about 110 miles north of Hope.

[Perturbed Member]

You think the GEM is better than the GFS?  Not saying your wrong, but I'm far from sure of that.

 

That was a quote from Mark Nelsen. I personally do not view the GEM as more reliable than the GFS. For short term detailed forecasts like this, I would also favor the mesoscale models like NAM and WRF over GEM as well. 

[Perturbed Member]

That is 2" more than we've seen all winter. Keeping expectations in check is a pretty critical part of not losing your sh*t here. This isn't a favorable setup for a widespread huge snowstorm.

 

IMO a widespread 1-2 inches from this event should be considered quite successful given the setup. 

[Requiem]

I don’t know, models are still being weird with the deformation band placement, and I definitely do think it’ll change. At least 1-2 inches is a possibility for PDX.