JoMo

Temps are really concerning, not just surface temps but 850 MB temps are pretty toasty.

Well, that was a warmer run and farther west as well on the Euro. Suspect it may have to do with the strength of the upstream "kicker" system digging into the SW and how it influences how wrapped up the main storm system gets. Variety of model solutions still on the table it looks like.

Quite the ice storm on the 00z GEM for eastern Arkansas this run. Not as much snow though.

Icon is farther west it looks but that's a ton of precip rising into subfreezing surface air.

12z gfs ensembles still show a variety of solutions. Not locked in yet.

12z Canadian is east of last nights run. Gonna have to see if the Euro shifts a bit east as well. I like looking at the Canadian as a preview to the Euro since I think they use the same initialization scheme?

The northern piece of energy is currently over NW Canada and the southern piece of energy is still off the west coast and won't be over land until tomorrow.

The 12z NAM had the stronger northern system, while the 12z GFS pushes it off to the east. Temps become problematic though until support arrives from the west from the upstream trough.

Well, the Canadian and Euro were fun tonight.

00z Euro should go boom. The northern stream system speeds off to the east leaving the southern system there to close off as energy digs into it's backside.

The difference between the 12z Canadian and Euro appears to be what it does with a piece of energy sliding down from the north. At hour 96 it's located over WY on the GEM and SD on the Euro. The Euro closes it off, while the GEM drives this piece of energy south and it gets absorbed into the trough. From there we get the closed low solution it shows with the ice and snow. The Euro closes something off around the same place as the GEM at 126 (southern OK) but then it's never really allowed to develop because of the northern energy it keeps around. I'm sure the Euro ensemble members that have snow are probably developing the more southern low.

Both the Euro and Canadian are interesting. The next few runs will be pretty telling.

Merry Christmas!

Yeah, I remember one year a big Arctic front dropped through, so cold air was available but the models were showing strong cyclogenesis across Montana or something with a strong approaching system. People were thinking that was crazy because there's no way the cold air could be scoured out that quickly, but the cold air quickly melted away under strong southerly flow. It got up into like the 60's after being in the teens the morning before. Sucks.

Wouldn't really make a difference, the storm system just wraps up too far west on the GFS. It needs to be more of an open positive tilted trough until it gets south of us, then it can wrap up. Anything else and the warm air is going to probably overwhelm the cold air sitting in place.

At this rate on the 12z GFS, we may have to watch out for severe weather. Nice Nebraska snow though.

Well, that didn't really clear anything up. 4 different model runs today, 4 different solutions on the GFS.

Yeah, southerly flow returns out ahead of the big system because the high pressure across the midwest is sliding off to the east quicker, due to the system in the northeast being faster, which results in the winds turning southerly, sooner. It's not just at the low levels, some kind of southerly flow happens throughout the atmosphere.

12z Euro was not great unless you live in KS, NW OK and NW MO. Nice 2 ft+ stripe in NE KS And NW MO.

Canadian gonna do some fujiwhara stuff. Still an interesting timeframe.

And it was still snowing after that..

Should be another one after that as well....... It does look interesting around New Years, pending temps which will probably be marginal again.

No dice on the 12z GFS and the 12z ICON changed back to the GFS'ish look. Canadian went more southern this run though. Hmm.

Surprise on the 00z Euro. Following the German ICON solution with a more southern system.

Interesting 12z GEM run this morning. Clips portions of the area on Christmas. Splits ways with the GFS at day 5 or 6.