Part I - January 2020 Weather Discussion for the PNW

[Requiem]

thanks so what we can we infer from it regarding us down here at sea level.

Cold.

[Omegaraptor]

I feel sorry for people who can't appreciate this run simply for the cold alone.  Pretty amazing.  I think we will get snow though.  Usually PNA blocks are better snow makers than EPO blocks.

 

This run is incredible and probably the best we've seen so far for the sheer cold. I know I said earlier that cold without snow is like pizza without toppings... but WOW.

 

Also, at hour 330 there's still lots of Arctic air left in BC... and it starts moving south again towards the PNW afterwards. 

[Gradient Keeper]

00z GEM Day 8.5. Took awhile to get there

 

[SouthHillFrosty]

I rather have record snow then cold but I’ll take what I can get

[Jbolin]

I feel sorry for people who can't appreciate this run simply for the cold alone.  Pretty amazing.  I think we will get snow though.  Usually PNA blocks are better snow makers than EPO blocks.

It'll be interesting to see how the GFS alone accounts for the 2mT shown and whether or not they verify, we would be looking at record cold given the #'s being shown. 

 

Snow right now is the lesser issue for me

[Guest LaPineLurker]

Hmm. So, how did you choose La Pine as a place to settle in? Surely you must have had some idea of the topography, no?

 

 

Actually I didnt.  My partner picked it.  He said it was the cheapest over here.  I went in knowing nothing.

[wxmet]

I know the focus is on the big storm mid next week, but I like the potential on Sunday for convergence zone snow with blustery winds over Seattle.

[Requiem]

Hey, cold is exciting, yeah, but that outflow is exceptional. Reminds me of the days before the Feb 1996 flood— powerful, brutally cold east wind.

[TigerWoodsLibido]

Actually I didnt.  My partner picked it.  He said it was the cheapest over here.  I went in knowing nothing.

 

Did not realise property in that part of central Oregon was that cheap.

[jakeinthevalley]

Mixed here. My phone app says could turn to all snow.

That will suck for all the sea lions that inhabit Burgess Road....idiot

[Brian_in_Leavenworth]

Advice from Mark Nelsen concerning weather apps:

 

"And, for the love of any sort of deity…stop staring at weather apps! They are good for general weather forecasting during benign weather, but useless in situations like this. Totally automated. Plus, what does a snowflake for next Monday mean; a snowy day? a few flurries?"

 

[Christensen87]

At least the 00z keeps us cold till the end of the run with another reload, unlike the 18z.

[Guest LaPineLurker]

Did not realise property in that part of central Oregon was that cheap.

 

Ya.  pretty cheap here, especially compared to Bend.  We got a pretty nice house here at a reasonable mortgage.

[Requiem]

Ya. pretty cheap here, especially compared to Bend. We got a pretty nice house here at a reasonable mortgage.

I know you’re new to Oregon, but have you ever been to Culver? It’s around there somewhere, I think.

[Guest LaPineLurker]

That will suck for all the sea lions that inhabit Burgess Road....idiot

 

Not sure what you mean but I do know Burgess road...cheers.

[Frontal Snowsquall]

Posted this before

Just East of Troutdale Columbia River!

I believe I took this in the late 80s

 

Wow, incredible picture! That looks more like the Kenai River than the Columbia!

[HighlandExperience]

I feel sorry for people who can't appreciate this run simply for the cold alone. Pretty amazing. I think we will get snow though. Usually PNA blocks are better snow makers than EPO blocks.

We are probably traumatized by Feb 2017.

[Guest LaPineLurker]

I know you’re new to Oregon, but have you ever been to Culver? It’s around there somewhere, I think.

 

 

Do you mean Carver?  I have a friend that lives in Oregon City and we went to a nice diner there before.

[snow_wizard]

Colder ensemble vs 18z and the 18z was colder vs 12z.  This run bottoms out at -10 for Seattle and duration of sub -8 is way longer than the 18z.

[Frontal Snowsquall]

I feel sorry for people who can't appreciate this run simply for the cold alone. Pretty amazing. I think we will get snow though. Usually PNA blocks are better snow makers than EPO blocks.

As they always say, get the cold in here first and worry about the moisture later. Sometimes moisture doesn't come into play until the last minute.

[Cloud]

thanks so what we can we infer from it regarding us down here at sea level.

At the 1000mb level you want to add 10 to 15C. Assuming -18c, you can estimate the temperature at sea level will be -8 to -3c over SEA. I’m sure you can convert this to F.

[Timmy]

I know you’re new to Oregon, but have you ever been to Culver? It’s around there somewhere, I think.

a lurker would not engage in answering a bunch of seemingly random questions. It’s totally him. Probably best to ignore.

[FroYoBro]

Like others said, Canadian is delayed from the GFS, but hits us with arctic air Monday night. 

 

I think the Euro will trend cooler again. 

[Frontal Snowsquall]

Jaya thinks this might be near record cold for western Washington

Go Jaya!

[snow_wizard]

Link?

 

That is just part of my general knowledge.  A PNA block is situated a bit differently than an EPO block and is located a bit further west.  Jan 1950 was a classic -PNA block and it was a huge snow maker.

[Blizzard777]

Wow, incredible picture! That looks more like the Kenai River than the Columbia!

It was a long period of cold and roaring East winds.  I remember the Sandy river was pretty iced over as well.  

good times and I still remember my face freezing as I was trying to get a good shot!

[snow_wizard]

At the 1000mb level you want to add 10 to 15C. Assuming -18c, you can estimate the temperature at sea level will be -8 to -3c over SEA. I’m sure you can convert this to F.

 

With Arctic air the temperature curve is different.  The surface is disproportionately cold compared to 5000 feet vs normal.

[TigerWoodsLibido]

FWIW, looks snowy for the weekend after next.

 

3-day totals ending that following Monday.

 

Only 7"? Psssh 

[Gradient Keeper]

00z GEM Day 8.5 510 thickness nearing PDX.

 

[wxmet]

GFS 00z early Sunday morning at KSEA showing good lift through the dendritic growth zone from 700mb to 850mb and temperatures at freezing at the surface:

 

[jakeinthevalley]

Do you mean Carver? I have a friend that lives in Oregon City and we went to a nice diner there before.

It's pretty cool there. You can see it from Mt. Scott

[Cloud]

With Arctic air the temperature curve is different. The surface is disproportionately cold compared to 5000 feet vs normal.

This is absolutely correct, but I just want to give him an idea of what we can do at the surface compared to 850mb height. Overall, it will be very cold at the surface.

[Guest LaPineLurker]

Did I choose the wrong side of the mountains?  What I am seeing on those maps is definitely snowier in Portland and Seattle?  

 

I remember Dallas getting some amazing snow sometimes, and OK city getting some crazy snow.   I figured being this far north would help matters.

[Perturbed Member]

thanks so what we can we infer from it regarding us down here at sea level.

 

You can think of the atmosphere as a series of layers. The surface/boundary layer where we live, 925mb, 850mb, 700mb, 500mb etc. Obviously in reality the atmosphere isn't made up of discrete layers like that but we tend to look at these specific points because they can be useful for forecasting purposes.

 

One of their uses is to determine precipitation type. We most often look at the 850mb temps for this. If the temps all the way from 850mb to the surface is at or below freezing and we have precipitation, then it will probably be sticking snow to the surface. There is no set in stone 850mb value that is good enough for snow, there are many other factors you need to take into account (onshore vs offshore flow, inversions, etc). In the Portland area, when we have the surface level winds coming out of the west, we typically need 850mb temps of around -8c or less to allow snow to make it to the surface and overcome the warming effects of the W/SW winds. If the winds are out of the east, you can get away with maybe 0c 850mb temps since the surface temps can be potentially kept much cooler/dryer due to the continental air. The 850mb temperature is just one data point you need to make a forecast. 

 

All you need to know in this case is, -18c 850mb temps over Seattle is WAY colder than you need for snow. It is near the historically cold category. 

 

There are lots of resources online if you want to read up in a lot more detail about this stuff, but stick around this forum and you'll also learn much more overtime. 

[Brian_in_Leavenworth]

Go Jaya!

He did say"if" and I know he is skeptical of such extreme solutions, especially from the GFS.

[Perturbed Member]

It's actually comical how hard the GEM always seems to want to shadow Washington county, it is definitely more than the other models. 

 

[Guest LaPineLurker]

I cant even begin to read that....good night everyone

[Gradient Keeper]

00z GEFS some improvement for PDX. Nice improvement for Seattle. Quite good for Yakima. I would like to see the ensembles improve far more than this and if the Op runs continue this, timing moves ahead we should see PDX mean temp to at least -10c if not -12c or so. We'll see....

[Perturbed Member]

Here comes the big snowmaker on the GEM now

 

[Blizzard777]

And finally, the obligatory 384 hour snow map.

 

You just have to...

384 hour map that doesn’t deliver for my area....good thing I can toss that one out