Winter Wizard

67 degrees on 11/11/95

If you're curious, the highest temperature DCA ever recorded the day before accumulating snow prior to today was 74 degrees on 4/7/72. If DCA recorded more than a trace, it would obliterate the record.

It's a bit of a misconception that the PNA corresponds to a western US ridge/trough, the index actually corresponds to a much broader area per the CPC: PNA = Z*(15°N-25°N,180-140°W)-Z*(40°N-50°N,180-140°W) +Z*(45°N-60°N,125°W-105°W)-Z*(25°N-35°N,90°W-70°W) So in the case of December, the -PNA was mostly the result of strong troughing over western Canada, which in turn torched the Southwest US. Good reminder that the number isn't the be all, end all, you have to look at the bigger picture.

All time worst bust for the Mid-Atlantic, imagine expecting 2-3 feet of snow from an all timer blizzard and instead getting at most a couple inches of slop. I was too young to remember this but I believe it was a case of a delayed transfer which shifted the heaviest snows way north into New England. I believe that trend was choreographed on some of the models, which makes me think that something of that magnitude *probably* won't happen again.

I am not sure when or why they decided to change the methodology but it really skews the rankings. I was surprised the 1/5-6/25 storm did not make the rankings considering it was a more impactful and wide reaching storm in the Ohio Valley and Mid-Atlantic than both early 2022 storms which snuck in as a Category-1. Or if those December 2022 storms could make it, why not 1/7/24 which brought a swath of 12"+ to the interior Northeast? Or 3/13/23? Anyway, the late January storm absolutely should make the rankings considering all of DC-BOS received over 6" of snow, and of course impacts spread well beyond that. My guess for that would be upper Category-3 or low end Category-4. For this blizzard, my guess is Category-3 in Boxing Day range.

I said this in the MA forum but figured I’d send it here too… I believe there is potential for 12"+ for coastal regions from Delaware to Mass, but I am honestly decently concerned about a potential rug pull I-95 N and W with this one. A storm as intense as this is likely to have a more consolidated precipitation shield which slams the coast, but can make it difficult for those bands to pivot farther inland. There is legitimate risk the phase does not occur until north of our latitude unless we see more digging upstream. The inverted trough is a wild card that could make up for it in spots though. Not to mention, surface temperatures are marginal with this one, and we could see a period of white rain cut down on totals. Hoping for the best, but I see clear warning signs and parallels to storms like January 2015, January 2018, January 2022, Boxing Day, etc.

That IVT has a January 2011 or February 2014 flavor.

I believe there is potential for 12"+ for coastal regions from Delaware to Mass, but I am honestly decently concerned about a potential rug pull I-95 N and W with this one. A storm as intense as this is likely to have a more consolidated precipitation shield which slams the coast, but can make it difficult for those bands to pivot farther inland. There is legitimate risk the phase does not occur until north of our latitude unless we see more digging upstream. The inverted trough is a wild card that could make up for it in spots though. Not to mention, surface temperatures are marginal with this one, and we could see a period of white rain cut down on totals. Hoping for the best, but I see clear warning signs and parallels to storms like January 2015, January 2022, December 2000, etc.

Lol I lurk more than people think. Don't usually feel inclined to post though.

I've been reading weather forums for half of my life and that was the most unhinged thing I have ever seen. Yikes.

Ceiling on this is very high, there will be a large swath of 12"+ totals across the Northeast. For the City and coast itself however, there is a twofold concern related to the transfer from primary low to secondary: mid-level warming and arguably more consequentially the dry slotting. I would not be 100% on major totals at this point, but potential is there. First bonafide MECS in 5 years.

If the 850 low is going to Buffalo like the Euro is showing, mixing would absolutely be on the table for parts of SNE, much less NYC southward.

Its own AI is north. Just seems like typical GFS shenanigans at play.

Garbage model, totally out to lunch. Toss.

I would consider the Euro to be the upper limit of this...IF everything aligns there potential would be there for most of the sub to see a foot+, just not sure where. My main concern would actually be dry slotting and a potential messy handoff between the initial low and the coastal.

Is there a major storm where the GFS WASN'T overly suppressed? I would be more concerned if it wasn't.

I would primarily focus on QPF for now, the Kuchera algorithm can be wonky. Having said that, I would expect favorable snow growth that would yield >10:1 ratios particularly in the second half of the storm.

Definitely good to see a more meridional height field.

TPV looks east and the northern piece looks stronger. Both good for increasing the ceiling and northward extent of the precip.

The Euro is a different evolution than we’ve seen: essentially a multipronged event with initial overrunning, a lull, and then transfer into a coastal where it bombs. Not far off from a February 2014 setup as a first thought. If the second piece comes in, that ups the ante and I really think HECS potential could be on the table. Fitting it’s basically on the 10 year anniversary of the last one.

100% agreed. Although, the big ones always lock in early

The AIFS obviously shouldn't be taken verbatim but I don't think it's far fetched to believe this isn't a one and done pattern. We'll be in a -NAO/-EPO/+PNA regime and that should keep cold air in place for the foreseeable future with a mean storm track targeting the East. I don't bite easily, but this has my attention.

I have not seen potential like this a long time in the Mid-Atlantic. Gives 2010 vibes. Just need to bring it home and hope it doesn't get squashed south.

From what I've gathered, verification stats have had Euro AI ensemble and EPS as pretty much neck and neck...sometimes the AI has had a slight edge but definitely not the magic bullet that some people imply. The AI has done better with individual storms, especially this hurricane season, but it also got its clock cleaned in others. Just like with every other model. My two cents is there is promise, but the jury is still out on when they are most useful and to what extent. There will always be limitations when the models are mostly data-driven instead of physics based.

For reference my hometown of Wilmington, DE hasn’t seen a 6” snowfall since March 2018 while I’m pretty sure almost everyone else on this forum and northward has. Unfathomably bad luck.