March 2020 Weather Discussion for the PNW

[jakeinthevalley]

37f with a healthy batch of rain moving in. A few flakes too. We'll see if anything happens overnight.

 

I am at 400 feet in West Salem

[umadbro]

Radar looks like a Clark county special.

[El_Nina]

Down to 35. Radar indicates things are about to get interesting. Wind is out of the NE.

[Requiem]

Looks like the easterly gradient has finally turned on.

[El_Nina]

Started as rain but is already transitioning to snow.

[Gradient Keeper]

Is it snowing yet?

[Perturbed Member]

Euro thinks ~34 is about as cold as PDX will get tonight. Still gives decent accumulations due to solid precip rates. The east wind just isn't gonna cool us off that much when it is 39F and raining in The Dalles. 

[Gradient Keeper]

Euro thinks ~34 is about as cold as PDX will get tonight. Still gives decent accumulations due to solid precip rates. The east wind just isn't gonna cool us off that much when it is 39F and raining in The Dalles. 

Not quite that setup with east wind arriving and bringing in the cold air. Nah.. This is all about steady precip with a slowly cooling atmosphere and nearly going isothermal. Almost! C'MON!!!!

[Perturbed Member]

Not quite that setup with east wind arriving and bringing in the cold air. Nah.. This is all about steady precip with a slowly cooling atmosphere and nearly going isothermal. Almost! C'MON!!!!

 

True, its kind of turned into that now. Earlier model runs did have the east wind as a bigger factor:

 

12z GFS thought the Dalles would be in the low 20s by early AM and clearly showed some of that cold air getting pulled in to the metro. It seems it has mostly caught up with reality as of the 00z run. 

[Gradient Keeper]

True, its kind of turned into that now. Earlier model runs did have the east wind as a bigger factor:

 

12z GFS thought the Dalles would be in the low 20s by early AM and clearly showed some of that cold air getting pulled in to the metro. It seems it has mostly caught up with reality as of the 00z run. 

Yeah and 00z WRF Delayed the east wind further. Time for a Gradient Keeper update

 

As of 12 AM

PDX-DLS -1.0mb

PDX-YKM: -2.1mb

PDX-GEG: -3.3mb

OTH-GEG: -2.0mb

YWL-BLI: -10.5mb

[Requiem]

True, its kind of turned into that now. Earlier model runs did have the east wind as a bigger factor:

 

12z GFS thought the Dalles would be in the low 20s by early AM and clearly showed some of that cold air getting pulled in to the metro. It seems it has mostly caught up with reality as of the 00z run.

So, as someone who isn’t too well-versed in this stuff— what’s this type of setup? East wind is still gonna be strong, but what’s gonna give us the snow the nearly every model is painting?

[umadbro]

Radar says the deformation is about kick into gear. Let's see where it goes.

[Perturbed Member]

So, as someone who isn’t too well-versed in this stuff— what’s this type of setup? East wind is still gonna be strong, but what’s gonna give us the snow the nearly every model is painting?

Mostly it will potentially come from having a chilly (but not that cold) airmass, the lack of marine influence (no onshore flow) and healthy precip rates. That probably won't be enough to get the lowest elevations to freezing, but if the precip rate is steady enough, you can still get slushy accumulations at 33-34F.

 

The east wind is there (currently pretty weak), it isn't really bringing very cold air but even a meh east wind is colder/dryer than any wind blowing out of the W or SW.

 

I think this is gonna cut it pretty close. Snow in the air is a given at any elevation now but not all low elevation places will get accumulation I think. We'll just have to see how it plays out. 

[Gradient Keeper]

C'MON !!!!!!!!!!

[umadbro]

3km Nam is already wrong.

[umadbro]

Gfs/euro is the best mix at this time.

[Deweydog]

GOLU

[Requiem]

12km NAM actually came out wetter. I guess it's just observation time at this point. Every model says snow, let's make it happen.

[Dave]

Low solar this evening.

[TigerWoodsLibido]

Up to 42F with light rain. Seasonably cool evening. Nice to have some rain for a change.

[umadbro]

35 with snow now

[Requiem]

35 with snow now

I haven’t switched over yet— should be a matter of time, hopefully.

[Perturbed Member]

I haven’t switched over yet— should be a matter of time, hopefully.

 

What's your temp?

[FroYoBro]

Doesn’t seem like it is going to switch to snow here.

 

Still 38 and it hasn’t gone down under this rain band yet.

[Requiem]

What's your temp?

Station near me is apparently 36. Council Crest is reporting snow already.

[umadbro]

Models failing miserably right now.

[Perturbed Member]

Models failing miserably right now.

 

Roads are still wet at both 1500 and 800 ft in the coast range. Currently running about 2-3F warmer than modeled by the already warmer 00z GFS. 36F and rain/snow mix. 

[Requiem]

Roads are still wet at both 1500 and 800 ft in the coast range. Currently running about 2-3F warmer than modeled by the already warmer 00z GFS. 36F and rain/snow mix.

FWIW it switched over here— EURO shows most accumulation a bit later on.

[Requiem]

I’m not giving up hope yet. RGEM, NAM, and EURO showed snow later on.

[Perturbed Member]

00z GFS shows a surge of east wind at 6 or 7 AM. Goes from a light breeze to a 20-25 mph sustained east wind at 925mb. Temps at 925mb drop from -2c to -5c quickly and the precip rate picks up at the same time and surface temps drop to 31-32F. We should still eventually get some cold air advection from the east wind eventually if that is right. That time period is probably the best chance for actual accumulation. 

 

Of course take what the FV3 says with a grain of salt. 

[umadbro]

Alot of rain below 1k right now.

[FroYoBro]

FWIW it switched over here— EURO shows most accumulation a bit later on.

That’s a good sign at least. Hope you get a couple of inches up there!

[Gradient Keeper]

I just ate some blackberry yogurt and now it might snow? This is exciting!

[umadbro]

Clark county below about 500 feet looks wet. Nothing to report the rest of the night

[Perturbed Member]

Yeah it's a non-event for folks without elevation most likely. At least as far as meaningful accumulation goes. 

[Requiem]

Yeah it's a non-event for folks without elevation most likely. At least as far as meaningful accumulation goes.

But very few models had anything right now...I’d give it time.

[FroYoBro]

It has been raining pretty hard for the last two hours and that has dropped the temperature to 35. Looks like I maybe used up most of my moisture though.

[Perturbed Member]

Real heavy stuff hitting near the airport.

 

[Perturbed Member]

Can see accumulation starting under the heavy precip areas.

[Perturbed Member]

There we go