January 2024 Weather in the PNW (Part II)

[Perturbed Member]

21 minutes ago, DeepFriedEgg said:

Looks like SW WA could be the winners here as they avoid that WAA. 

Don't want to speak to soon but at least PDX metro won't have to deal with as much ice as the rest of the valley. This is going to be a crippling ice storm for much of the valley.

Still feel the models are probably overdoing the WAA but the GRAF is also a pretty decent model for these kind of details so certainly not a good trend there. 

[Doinko]

45 minutes ago, Perturbed Member said:

06z NAM 

Looks pretty good, most models shpw at least something here.

[Perturbed Member]

06z ICON

It sees some sleet and ZR in there too. 0.80+ in of QPF but less than 7 inches of snow. 

[DeepFriedEgg]

1 minute ago, Doinko said:

Looks pretty good, most models shpw at least something here.

I think we will get at least an inch or two. That is what I have set my expectations at. Hoping for a surprise! (not in the ice direction!)

[Doinko]

1 minute ago, Perturbed Member said:

06z ICON

It sees some sleet and ZR in there too. 0.80+ in of QPF but less than 7 inches of snow. 

RDPS also shows a bullseye towards Clark County and SW WA. Hopefully we can avoid the sleet but it still looks like a pretty good storm

[DeepFriedEgg]

GFS bullish that it stays mostly snow, especially for Washington county. (cold air damming on coast range and Chehalem mountains?)

[Doinko]

06z GFS

 

[DeepFriedEgg]

2 minutes ago, Doinko said:

RDPS also shows a bullseye towards Clark County and SW WA. Hopefully we can avoid the sleet but it still looks like a pretty good storm

Even if it ends up mostly sleet, the low level CAA should be impressive. If we get sleet and 50mph gusts.... Yikes! That would hurt.

[DeepFriedEgg]

1 minute ago, Doinko said:

06z GFS

 

That looks like a more classic warm nose. Hoping it works out like that even if unlikely.

[SnowySeeker50]

6z GFS Sleet and ZR totals

[Perturbed Member]

The RGEM is pretty drunk. Shows plenty of precip but keeps it mostly ZR and sleet. 

You look at this map and it looks like there is quite a bit of WAA above, but then you look at the sounding and there really isn't really much of a warm layer there. Somehow the P-Type it shows on that sounding is still ZR without any real above freezing layer. 

The warmest area based on that sounding is near 850mb and looking at the 850mb chart, it is still at or below freezing, especially for WA county. You can see a bit of a warm nose in the usual spots to the SE though. 

 

I would take the RGEM's precip type estimates with a grain of salt here. Seems pretty goofy. 

[DeepFriedEgg]

1 minute ago, Perturbed Member said:

The RGEM is pretty drunk. Shows plenty of precip but keeps it mostly ZR and sleet. 

You look at this map and it looks like there is quite a bit of WAA above, but then you look at the sounding and there really isn't really much of a warm layer there. Somehow the P-Type it shows on that sounding is still ZR without any real above freezing layer. 

The warmest area based on that sounding is near 850mb and looking at the 850mb chart, it is still at or below freezing, especially for WA county. You can see a bit of a warm nose in the usual spots to the SE though. 

 

I would take the RGEM's precip type estimates with a grain of salt here. Seems pretty goofy. 

That's encouraging. We'll see what Mark says tomorrow now that the track and QPF is more resolved. Also, even if the 850s are around 1C, does that guarantee sleet? Hard to believe that the snow would melt that quickly. Seems like you would still get snow but just with less favorable ratios (icy snow instead of just powder). I guess it really depends on the thickness of the warm layer (use soundings).

[Perturbed Member]

6 minutes ago, Doinko said:

06z GFS

 

A 992mb low there with solid cold air in place and good outflow, it just looks like a classic setup for us. I think we're set for at least a few solid inches, especially out west in WA county. I think PDX metro in general should be ok. Probably will see some sleet in parts of the metro for at least part of this but I think enough will still be snow to get a solid event. 

[Doinko]

Just now, Perturbed Member said:

A 992mb low there with solid cold air in place and good outflow, it just looks like a classic setup for us. I think we're set for at least a few solid inches, especially out west in WA county. I think PDX metro in general should be ok. Probably will see some sleet in parts of the metro for at least part of this but I think enough will still be snow to get a solid event. 

Yeah, GFS looks good for a solid event. Wasn't the warm nose overstated in 12/20/2008? I know they're not completely similar, just curious about what models were like

[DeepFriedEgg]

1 minute ago, Perturbed Member said:

A 992mb low there with solid cold air in place and good outflow, it just looks like a classic setup for us. I think we're set for at least a few solid inches, especially out west in WA county. I think PDX metro in general should be ok. Probably will see some sleet in parts of the metro for at least part of this but I think enough will still be snow to get a solid event. 

I know, placement is just perfect! I'm just going to expect the worst (especially because of the trend to more WAA aloft) which will make a possible surprise that much sweeter.

[Perturbed Member]

1 minute ago, DeepFriedEgg said:

That's encouraging. We'll see what Mark says tomorrow now that the track and QPF is more resolved. Also, even if the 850s are around 1C, does that guarantee sleet? Hard to believe that the snow would melt that quickly. Seems like you would still get snow but just with less favorable ratios (icy snow instead of just powder). I guess it really depends on the thickness of the warm layer (use soundings).

Yeah it comes down to a combination of how thick the layer is and what the temperatures are across the warm layer. You can get away with it to a certain extent, if the warm layer isn't too thick or if the temps are only modestly elevated in that layer. 

The good thing is that the Euro and GFS show a much more modest intrusion of warm air aloft. I feel pretty good about keeping it almost all snow under the scenarios on those models. 

[Doinko]

Either way, Saturday morning looks pretty extreme here. 50mph gusts for a decent period of time

[TigerWoodsLibido]

Surface Arctic boundary is about to hit The Dalles.

[Jbolin]

Holyf**k it's cold out there. 

[TigerWoodsLibido]

The Dalles just dropped like 10F in 10 mins. DP crashing as the Arctic boundary is now about to enter the western portion of Wasco County and into the Hood River Valley.

[CasuallyFoxy]

Pretty aggressive CAA through the gorge, The Dalles went from NW 9 to E 36 in 10 minutes.

[TigerWoodsLibido]

Just now, CasuallyFoxy said:

Pretty aggressive CAA through the gorge, The Dalles went from NW 9 to E 36 in 10 minutes.

Gonna be interesting to see how fast this makes it down the valley.

[Ken in Wood Village]

I woke up around 1:30am (I think) and looked at this map. I wanted to find out where the cold air is. At that time, The Dalles was 39° degrees....it's now 29 with a NE wind. Look at some of the temperatures. A lot are in the single digits but a few a way below zero. The cold air has arrived and soon those East winds are coming. It's going to be brutally cold 🌨

[Tanis Leach]

Newest video (with mini bit on Gorge model issues and why that makes me deviate from the hi-res models showing more ZR in the metro): 

 

Technical info:

Tossed between 2-5 and 3-7" of snow. Leant 3-7" due to the disclaimer in the video (assumes mostly snow, so reduce if there is more sleet), and QPF being an estimated 0.6" for the event in my forecast. Gorge issues and Cold air damming are making me deviate slightly from the hi res models as well. 

Do not take the lines to scale, they are to provide a general area of who could see what. 

You can also probably tell I'm tired in the video.

 

[Gradient Keeper]

1 am 850mb temps. That's impressive! Now imagine if that ridge had held for another 1-2 days. Top tier blast without a doubt.

[Gradient Keeper]

44 minutes ago, CasuallyFoxy said:

Pretty aggressive CAA through the gorge, The Dalles went from NW 9 to E 36 in 10 minutes.

Very much so. Comparing the progress of the arctic front with the 00z WRF 1.33km it's right on schedule. The boundary moving in from the north is a bit behind modeling though just north of Castle Rock. The fact the WRF is doing that well with the backdoor front into the eastern Gorge means it may be quite close with pressure gradient forecasts and if so, areas east of I-205 especially Gresham, Troutdale, Fairview, Wood village are going to see very strong possibly damaging winds. Another area of similar winds for the Foothills up into Clark County and even the West Hills. There is the potential before this east wind storm is over that we could see the strongest east winds in 20-25 years.

12z GFS in 4 hours 7 minutes

[Front Ranger]

Looks like Olympia area may end up being one of the bigger winners with Arctic front, outside of Sequim/Port Angeles area.

[Gradient Keeper]

[Gradient Keeper]

4:23 am Arctic front through Castle Rock, and in the eastern Gorge through Rowena and Lyle now. Next up: Mosier, Hood River.

[SilverFallsAndrew]

Gradient down the valley is pretty much dead it seems. Calm winds at PDX and SLE. Can’t wait to see these flip around to east and north. 

[SilverFallsAndrew]

The ridge the ensembles build toward the end of the month does look primed to retrograde. 

[MossMan]

Currently 15.8 degrees.

DP 7

[MossMan]

We are beating poor Alaska! 

[SilverFallsAndrew]

Gfs 

[LowerGarfield]

It's still snowing here and hasn't stopped all night. Hard to tell how hard it's been falling though but US 12 is covered. The local district says they evaluate the roads at 4am and notify families by 6am if there will be delay oe cancellation. With the snow and the Arctic air I'm almost tempted to say nope not today.

[Gradient Keeper]

5:03 am Arctic front just now into Kelso.

[Ray]

When I left home this morning at 3am it was 25 degrees and just a light dusting of snow. The light snow didn't surprise me but I was expecting much colder. Even though we got skunked in the snow department there is still plenty of winter left. Just need to keep the faith. 

[GHweatherChris]

lame

[Everleigh]

Checking in from Yelm. I have about 4 inches of snow this morning. It started with the pellety type snow around 8:30pm, and it's still very lightly snowing now at 5am. No call from the school district yet though.... 

[snow maniac]

Just a dusting of snow here.