PNW December 2022, winter might be coming; but mostly canceled.

[Perturbed Member]

00z Euro had PDX at 35F DP 20F by 4 AM. The 00z GRAF had them at 35F DP 23F. 

As of right now PDX is reporting 41F with a DP of 19F. Was hoping things would cool off a bit more by now but that is still a wet bulb temp of ~33.3F at PDX. The wet bulb temps are a bit lower in the suburbs as expected. 

By noon we have pretty decent cold air advection at 850 mb (which weirdly is coming from the south), dropping about -4.5c from 4AM to 12 PM. Hopefully that combined with the wet bulb and decent precip rates will be enough. 

[SilverFallsAndrew]

Full disclosure I’m gone from the 15-19th, so I’m hoping for a pattern reset or some cold inversions during that time. Lol

[SilverFallsAndrew]

1 minute ago, Perturbed Member said:

00z Euro had PDX at 35F DP 20F by 4 AM. The 00z GRAF had them at 35F DP 23F. 

As of right now PDX is reporting 41F with a DP of 19F. Was hoping things would cool off a bit more by now but that is still a wet bulb temp of ~33.3F at PDX. The wet bulb temps are a bit lower in the suburbs as expected. 

By noon we have pretty decent cold air advection at 850 mb (which weirdly is coming from the south), dropping about -4.5c from 4AM to 12 PM. Hopefully that combined with the wet bulb and decent precip rates will be enough. 

Bummer that PDX has no chance at a sub-40 high. 

[snow_wizard]

1 minute ago, Perturbed Member said:

00z Euro had PDX at 35F DP 20F by 4 AM. The 00z GRAF had them at 35F DP 23F. 

As of right now PDX is reporting 41F with a DP of 19F. Was hoping things would cool off a bit more by now but that is still a wet bulb temp of ~33.3F at PDX. The wet bulb temps are a bit lower in the suburbs as expected. 

By noon we have pretty decent cold air advection at 850 mb (which weirdly is coming from the south), dropping about -4.5c from 4AM to 12 PM. Hopefully that combined with the wet bulb and decent precip rates will be enough. 

925mb temps are shown to be colder than you would normally expect with the 850s being shown.  It looks promising.

[snow_wizard]

All I can say for the Seattle area is if models aren't pushing enough moisture far enough north (better than 50% chance of that) 1 to 3 inches could easily happen.

[Meatyorologist]

Going by the timing being during the day tomorrow, I doubt it accumulates that greatly tomorrow. But if even an inch falls, there'll be some real chilly weather this upcoming week.

[WeatherGeek2022]

2 hours ago, snow_wizard said:

That is nasty looking.

hanukkah eve repeat? 

[snow_wizard]

2 minutes ago, WeatherGeek2022 said:

hanukkah eve repeat? 

It would be close for some places if it plays out as modeled.

[snow_wizard]

8 minutes ago, Meatyorologist said:

Going by the timing being during the day tomorrow, I doubt it accumulates that greatly tomorrow. But if even an inch falls, there'll be some real chilly weather this upcoming week.

I don't think time of day will matter that much.  I thought it would on Wednesday, but it really didn't here.

[umadbro]

[Meatyorologist]

1 minute ago, snow_wizard said:

I don't think time of day will matter that much.  I thought it would on Wednesday, but it really didn't here.

Big difference in the city though where the concrete surroundings absorb and emit thermal radiation more effectively. Also near sea level in elevation. I've seen colder airmasses struggle to cool to the wet bulb efficiently with similar southerly deformation extents. Not saying precip won't be in the form of snow (it will), but whether it sticks or not is a different story.

If precip is heavy enough though, there should be no problem.

[Meatyorologist]

Some heavier showers entering the Portland area. Should be in the form of snow, but a lot of it will fall as virga. Dewpoint depressions on the order of 15F+ with a stiff easterly breeze.

[Requiem]

4 minutes ago, umadbro said:

Nice to see some of these early echos are already pretty robust-- hopefully showing that this is that dynamic sort of system we look for as far as precipitation.

[umadbro]

1 minute ago, Requiem said:

Nice to see some of these early echos are already pretty robust-- hopefully showing that this is that dynamic sort of system we look for as far as precipitation.

One thing I take is that the moisture doesn’t give a F about the offshore flow.

[snow_wizard]

The month to date average through yesterday (Dec 3) at Sumas is a ridiculous 23.8.

[Meatyorologist]

28F

[Deweydog]

Kinda bizarre how reminiscent this is of a warm season tstorm pattern.

[umadbro]

1 minute ago, Deweydog said:

Kinda bizarre how reminiscent this is of a warm season tstorm pattern.

I was telling my wife earlier that if this was July we’d likely see thunderstorms

[snow_wizard]

1 minute ago, Deweydog said:

Kinda bizarre how reminiscent this is of a warm season tstorm pattern.

This has been a fascinating progression on this system.

[Meatyorologist]

5 minutes ago, Deweydog said:

Kinda bizarre how reminiscent this is of a warm season tstorm pattern.

midlevel instability!

[snow_wizard]

6z GFS pushes moisture further north.  Possible flurries in the morning now.

[Perturbed Member]

Pretty convective looking echoes

[Hyperbolic Trendz]

Sleetpocalypse!

[snow_wizard]

4 minutes ago, Meatyorologist said:

midlevel instability!

This thing is weird enough that surprises are inevitable. 

[umadbro]

[Perturbed Member]

6 minutes ago, Meatyorologist said:

midlevel instability!

This sort of stuff is probably what is causing some of these models to spit out these wild 0.8-1.2 in QPFs on some of these runs the past 24 hours. Someone in the region is going to end up benefiting from these dynamics and score a good surprise I think.

[CasuallyFoxy]

6 minutes ago, umadbro said:

This was coming down as entirely graupel, was pretty noisy for a while.

[umadbro]

Just now, CasuallyFoxy said:

This was coming down as entirely graupel, was pretty noisy for a while.

Sign me up.

[Hyperbolic Trendz]

3 minutes ago, umadbro said:

Similar scene in Gladstone comprised mostly of sleet with some legit snowflakes caught up in the bedlam.  That shower was intense and surprising but now has passed. A few of those sustained, as Perturbed mentioned, would do the trick in the morning.  Really liked the timing of this one though. 

[Perturbed Member]

 

Sleet?

[Requiem]

Something frozen falling with very strong easterly winds 

[Perturbed Member]

Whoa, its just straight up snowing here. 

[Requiem]

1 minute ago, Perturbed Member said:

Whoa, its just straight up snowing here. 

Wow, a good sign if we can get more precip. That's mostly what I'm worried about at this point-- I think wet bulb will give us some surprises. 

[Perturbed Member]

Just now, Requiem said:

Wow, a good sign if we can get more precip. That's mostly what I'm worried about at this point-- I think wet bulb will give us some surprises. 

I'm seeing very little rain if any, its pretty much all snow. 

Good sign for the morning I think. Liking the convective nature of this precip too. 

[LowerGarfield]

40 minutes ago, Perturbed Member said:

I'm seeing very little rain if any, its pretty much all snow. 

Good sign for the morning I think. Liking the convective nature of this precip too. 

Anything sticking at your location? That's exciting.

[TT-SEA]

No idea why I am awake right now... but the 06Z ECMWF is hot off the presses and looks significantly wetter to the south.   Going to be fun to track this today. 

[TT-SEA]

Zoomed in on Portland...

[Requiem]

5 minutes ago, TT-SEA said:

Zoomed in on Portland...

Think some spots will see a few surprises-- maybe.

[The Blob]

41 minutes ago, TT-SEA said:

Zoomed in on Portland...

I'll take the almost 2in at work

[TacomaWx]

Looks like some radar returns are almost here already.