JoMo

Nothing much to really update as the models are basically all falling into line. Generally a light snowfall, gusty winds, and really cold temps on the way for most of us. 

Definitely the main threat with this system though as stated by Springfield's AFD. 

"NBM probabilities show the potential for wind gusts up to 50 mph Thursday into Friday, which may result in power outages." "These cold temperatures in combination with strong gusty winds will result in wind chill values near -30F Thursday night into Friday morning. For reference, the last time wind chills dropped below -30F at Springfield was in 1989. Frostbite will occur in 15 minutes or less in these conditions."

00z Euro ended up farther NW. 

SW shift on the 00z Canadian. 

2 minutes ago, MUWX said:

It was fun while it lasted 

lol. Still a lot of runs left. Congrats Minneapolis?  

There has been a noticeable shift SW on the last 3 runs of the ICON for sure. 

22 minutes ago, rockchalk83 said:

Man, that's one juicy GFS run. I'm lost trying to figure out what the moisture source for the system is. But, if it happens like this....widespread blizzard conditions for a lot of folks. 

It's dynamics plus the extent of the cold air. I just noticed the 50-55 kt 925 MB winds at hour 99 on the backside. Sheesh. (Although the GFS is usually too wet this far out)

Temp of 4 degrees, moderate snow and 30 MPH winds seems fun. 1004 MB surface low to 989 MB in 6 hours and still dropping rapidly. 

57 minutes ago, Wx 24/7 said:

The EURO ensembles seem less impressive to me today. 

I am still less than assured that this is a strong setup. Some snow for Christmas would be great. The cold is still looking nuts. 

Yeah, the cold is a sure thing. The amount of snow and how far south it gets is more uncertain. The one thing that has been happening is the Euro has been caving to the GFS more and more this year. Also stuff has been ending up farther west over time. Time will tell. 

19 minutes ago, MUWX said:

I’ll never forget a couple years back when we were under a winter storm warning and it still completely busted. 

I'll never forget that time that we were under a WSW and the system came out farther NW than predicted. Wichita looked at the satellite and immediately dropped all their warnings since all the models were wrong and it was tracking farther NW. Springfield stood their ground and were completely wrong as temps stayed too warm for snow. 

5 minutes ago, MUWX said:

I’m not gonna lie…I saw this before the model and was expecting a lot more than 4-6” lol 

Kuchera ends up being a couple more inches because some of the snow falls in the teens and single digits. 

More 00z GFS ensemble members hopping onboard with some kind of snow with the system next week but there's still room for failure. 

Better agreement with the 12z GFS/Canadian as well. Snowfall amounts still not set in stone though. 

Still a large amount of ensemble spread on the 18z GFS for the 12/22 system so don't be surprised if next run is drastically different. 

The south/western shift on the models with the 12/22 system continues with the 18z GFS. Nice!

12z Euro gonna have a different look for the storm on the 22nd. Interesting. Hope the models reel this one in.

Ensembles will give you a broader picture when it comes to long range outlooks. They're best used to see a general pattern and to check if the deterministic (control) is an outlier. I remember a few years back we were looking at a snow event and following the ensembles and they all ended up being wrong. Had like a 90% chance we'd get snow drop to a 0% chance in like 2 model runs. 

GFS is still pretty robust with that system on 19th. 

Trend is still not great on the 00z GFS/GEM for snow before Christmas. 

57 minutes ago, MUWX said:

The Euro is something…. 

I have concerns it ends up farther NE than what the OP Euro shows . 

Pass on the 12z runs. On to the 18z. 

20 minutes ago, StormChazer said:

Well that GFS run was MUCH less fun.

And the Canadian was no fun at all. 

00z Euro with rain on the 19th and then waves of snow on the 21st-22nd with entrenched Arctic air and a SW flow aloft with the main system still coming together in the SW US at the end of the run. 

What a fun 00z GFS run tonight. Still has the snow on the 19th and then has a massive system on the 22nd/23rd and then maybe another system after that. 

It's so precarious. One small change in the flow/timing and we go from rain on the 19th on the 12z GFS to a snowstorm on the 19th on the 18z GFS.