andyhb

Eh, historic would mean 18"+. The marginal temperatures are really putting a damper on what could be a top 5 storm.

No other model has it that far north/pronounced despite many with similar SLP tracks. I have my doubts.

NAM has this huge slug of warm air aloft at 850 mb + the surface temps are marginal. Cuts into snow totals significantly across the board.

Eh? The Euro/EPS is stronger because the primary shortwave is deeper and more organized than on the GFS, not really due to phasing.

Decided weaker/east shift on the GEFS. Historic storm off the table there.

Lol main shortwave is too flat on the 12z GFS again.

Those 00z runs were almost unanimous on a top 5 type snowstorm for Chicago and a wide swath of the Midwest. This thing is an absolute nuke when that shortwave kicks negative tilt and the mass evacuation really intensifies. The PV streamer into this thing is going to be a sight to behold on near-term guidance/satellite.

Now with that said, there are a large number of members that are stronger/further north or west than the operational. Hell, the mean is nearly as deep as the operational at 108 hrs.

12z Euro still has that slider/weaker look. Looks to track close to Cleveland.

I'd imagine this one will be dubbed the MLK Blizzard if it comes to fruition.

Widespread 50+ mph gusts pushing 60 at the lakeshore that run. Would be an upper echelon blizzard for a large chunk of the subforum.

That is simply filthy at 500 mb.

There are a lot of GEFS members with sub 970 mb solutions by the time the storm gets to the lakes this run. Definitely a majority.

00z high res guidance is not painting a pretty picture for the central Gulf Coast tomorrow night. Incredible shear with 70-80 kt LL flow and the potential for embedded supercells. It’s going to be hard to keep that warm sector offshore with gale/storm force southerlies trying to advect moisture north.

18z GFS is super weak and south, we’ve come full circle.

…Euro is instead super dry, a bit too “slider-esque” still and too broad with the main shortwave.

12z runs have been pretty stout thus far and the Euro is coming in shallower with the lead wave on Wed/Thurs. Seems to have better wave spacing between the two as well.

I think it's more likely for the Friday system to get suppressed south/shift too weak than cut that severely. That -NAO block is stout.

18z GFS is a higher end share the wealth solution. Ideal track for St. Louis, Chicago, and Detroit to get buried.

Basically what it comes down to is that 1/11-13 shortwave needs to be the dominant one in the wave train for this potential with this to take off. In other words, it needs to be slower/amplify more in the west prior to ejecting into the Plains.

If we see the ensembles start to emphasize that in-between shortwave more in the next few runs, then we’ll know it might be curtains for the high end. Going to be difficult to get 3 consecutive waves to amplify significantly regardless of your background regime. Edit: EPS mean still looks rather promising.

The wave in between the first system and the one we’ve been tracking is now too deep/amplified as well. There’s no moisture leftover for that one to be the big storm. Storms with so many moving parts like this tend to be very iffy.

12z Euro is a total bust because the shortwave doesn’t amplify and just slides east. Number one concern with this one.

Thanks for saying all of this more eloquently than I can. Yeah the difference in the ensemble means (particularly the GEFS from the GEPS and EPS) in handling the PV interaction makes me think that this main wave needs to amplify in the west initially to avoid a) sliding east/south and turning into a nor’easter and b) getting suppressed to the point of a lesser event. CMC operational showed the former. If the timing is right though, the Euro, GFS, and what would be the UK just beyond range are the types of potential you look for once a decade essentially.