SnowGoose69

Usually anything from like 1-3 to 3-5 is most common. Some rare instances where 6-7 has occurred for the coast like February 2008 November 2018 December 1990 but those usually consist of one of two scenarios. Weak waves vs amping lows or the system approaches more from down in the Carolinas vs the Tennessee or Ohio Valley.

Unfortunately the classic SWFE has become somewhat of a lost thing in recent years much like the clipper and coastal track have seemed to. I think it’s a product of stale highs due to warming in Canada coupled with systems having a tendency to want to overamp more in that setup vs just remain weak flat waves bumping into highs, I can’t remember the last case of that we had. We have seen more SWFEs have long duration periods of sleet which 20-30 years ago almost never happened. They were usually snow to rain 9 out of 10 times

Faster evolution. That’s the key here really. I don’t believe that scenario in early December would remain all snow even if that exact track panned out but the key here really is get that second system to develop as fast behind the first as it can while the high is still in decent position.

Yeah first system being the lakes storm which is in essence a glorified FROPA here. That system over the last 8-10 days has gone from a Midwest cutter to a solid Lakes cutter to a weak lakes low. This is what mostly led to the failed SER. That SER shown 10 days ago was a product of that assumed massive cutter.

The first storm continuing to gradually become strung out and flatter is leading to the second one being more likely to be a hit. 2-3 days ago I felt the second system was a miss but not so much anymore. That said, keeping with the theme of recent years and given the flow, go weaker on that one too. I believe there is a decent chance for the 2nd storm to be snow to rain, even to the coast if everything times out correctly but if it’s too late and the high begins to slide offshore it won’t happen

GEFS/GEPS in a snap shot mindset do not look great D14-16, but they're in the process it seems of evolving to something different. A ton likely depends on where the MJO goes

Not surprised to see it was during a Nino too where Dec tends to lean milder anyway. I think we had a small snow event in SNE a few days prior to that too.

I think a big part of the reason we lost the SER in early Dec is the storm system D5-6 ended up much less amped and not like a bomb models shows 3-4-5 days ago. Now of course they try to do the same thing with the ensuing storm, once again I am inclined to lean flatter as that has been the trend seemingly forever. If we don't get a monster cutter into the Lakes or MW the SER will keep verifying weaker in the medium range. The question is if the LR is going too weak on it. If we do blast hard into phase 8, that will certainly help

It looks transient and more like a reshuffle though on the GEPS/EPS, you can see D15-16 already it seems a ridge is trying to begin popping again in W Canada or along the coast. I'd be surprised if we have that rabid of an MJO wave going into 8 that we see a pattern like that, though once in a great while we've seen a raging -PNA/+AO/NAO with a phase 8 MJO, I think maybe January of 1990 we did, but I'm not sure if its ever been with a wave potentially that strong.

This is about as strong a look we've seen for it to get into phase 8 in several years. I'd be surprised if it did not get there, and yeah, ensembles just never see a moderate-strong MJO wave impacts it seems. Its why so often here when we see a raging 3-4-5 forecast but the D16 ensembles look like January 94 you more or less know that look will be way off if that 3-4-5 wave verified.

No surprise to me, a trend already showing today that the storm near 12/1 in the Plains/MW may not be as strong. Solutions were just unrealistically amped the previous 2 days which is why I said be wary of bridge jumping over the SER 12/1-12/4 because if we went the way we've gone most recent winters, those types of bombs, even in that part of the country have been hard to come by. Weaker or more strung out system there that SER won't pump anywhere near that strong

It’s why I’m not sold on the massive SER in early Dec. the problem last winter and when in recent weeks when ensembles tried showing that was it was solely based on some type of huge cutter developing and pumping the ridge. But in fast flow even those have a hard time developing

The EPS much like most recent winters is getting beaten by the GEPS/GEFS in that range in regards to that E Pac/AK pattern....the 00Z run is again trying to build a SER post D12 again. I think part of what is happening is the Pac is still progressive so the EPS tries to develop these wild storms like Panhandle hooks and cutters and the flow just is not allowing for that type of activity to end up happening. As a result, there is much less SER in the end. Also the GEFS have backed away a bit from the -PNA magnitude the last 2 days on the ensembles after D10. The most glaring bad news I see in last 2-3 days is the flow is still just screaming. You can look at the last 3-4 GFS Op runs alone to see how we went from dumping cold into the W to the dump now despite going E does not make it significantly far into the Mid-South or SE because the progression of everything. Until that problem goes away we ain't seeing any consistently stormy pattern for the NE or MA

Good news perhaps with regards to the RRFS....it did a spectacular job today on ptypes in Michigan and seems to have a good handle here tomorrow AM on the R/S line. With the NAM being discontinued sometime in 2026 it was really important that the RRFS performed well on winter precip events given the HRRR and GFS are relatively awful usually being too cold aloft and the HRRR sometimes in the BL too. The RRFS not having a MOS product though will continue to be a problem.

Also the PNA is likely to go + in that period, at least historically I think 95% of -EPO/-PNA E QBO Decembers had a +PNA January