jm1220

If near warning snow is making it to Boston, a chunk of what my backyard gets even will likely be sleet. I know other models are colder but we’ve seen them verify too cold in these type events. It’s clipper like but behaving like a SWFE with overrunning into cold air. Like that or not, take what you will but historically SWFE is not good for NYC. It’s not your typical SWFE for sure but these overrunning deals so often pull the rug out by trending north at the end. We’re at the point where we just have to see what happens. Hopefully we get good precip that doesn’t shoot over way NE and we’re not waiting for hours in the city as it warms in the mid levels.

25 here.

Probably. We'll know the nature of this in the morning/early afternoon. If the heavy snow shield looks like it'll pound the city and Allentown gets a couple hours of good snow, that's a great sign for the city that they'll hit warning totals. If the heavy snow instead looks like it will overshoot the city and nail ALB to HFD, the city is dry in the meantime and Allentown starts right off as sleet when heavier precip finally gets there, NYC will likely underperform because the big WAA snow push is happening north of the city, warm air will get chances to advance aloft in shredded/crap precip and when it gets here it'll be too late.

Obs and totals thread created.

Post obs and totals here. Good luck to all. Some guesses: -Central Park 4.8", JFK 5.0", MMU: 4.2", HPN: 6.7", EWR: 4.0", ISP: 7.0", BDR: 7.3" New Brunswick: 2.8" Middletown NY: 7.5" Newburgh NY: 7.1" PHL 1.2" of crud, TTN: 1.6"-a little more snow but still mostly crud, ABE 2.1"

Yep-the thump happens then the snow turns to shredded, and the sleet line advances in. I can't see soundings but verbatim from the sim radar that's what looks like happens. There does seem to be a good shot at hangback snow after the low begins to depart and the cold air returns in the mid levels that could add another inch or two around dawn on Sat. Again it's one model's interpretation but IMO it can't just be dismissed.

We have a banter thread, please use it for non-storm related stuff. And the "storm cancel" stuff, I don't care if it's meant in jest, trolling or frustration but I'm removing those. You can go to banter or just not post it.

The heavy banding would help keep the mid level warm air at bay. The 0z NAM 3k has kinda crappy QPF across the area which you can see in soundings-when precip is patchy/shredded you see the mid level warm air show up more. The major overrunning snow shield overshooting to the NE is always a possibility here.

When it comes to how far the mid level warmth gets I don't ignore it because as others point out it's closer to accurate most of the time. And soundings do get dicey for the city from 0-3z especially, that 750mb warm nose will mean business. Even my backyard gets very close to changing to sleet. If we see good snow surging into eastern new England, NYC very likely changes to sleet. The block has to shove this south in time. But no I don't think it's gospel and I've seen situations where it overdid the mid level warmth. However it's probably closer to right than the colder models and I don't buy for a second that a storm like this will drop good snow from TTN-PHL with a 700mb low in upstate NY.

Not every time. It’s been too aggressive in the past. Last Feb’s SWFE it was too aggressive.

I don't see a big NE shift. Maybe 25 miles or so. And maybe came down a little on QPF.

If it comes in heavy it’s possible those places on the NE corner of the map reach warning amounts. These storms are always a race between the warm mid level air and heavy snow piling up before the warm air wins. If it comes in shredded the warm air has an easier time advancing in most cases. In the Dec 2020 storm that’s what minimized it east of the city. I’d be expecting largely a sleetfest from Allentown to Trenton to Philly. The tougher call is NE of there. It’s possible that sleet makes it into the SW part of NYC especially if that shredded up snow shield happens.

And today just stop with the bickering. Just stop. Go enjoy time with your families/friends if you can’t help yourself here today.

Tough forecast for sure for New Brunswick along I-78 then south to Trenton. I’d go with maybe a few inches there but expect that sleet could cut into it quite a bit. Like others have said the sleet usually ends up north of where it’s supposed to and sometimes by quite a bit. But if it comes on like a real thump then maybe the colder models could be closer to right since a lot of snow will fall before warm air aloft can ruin it. You can almost always count on the late north shifts on these type of storms unless a strong block can stop it. Anyway-try to enjoy whatever happens and Merry Christmas/happy holidays.

The Feb 2025 SWFE brought a widespread 4-6" because the snow came in like a wall and held off the warm air.

Last minute north bump on a SWFE type system- color me shocked. I think from the city east has enough wiggle room here to hold on but I’d be sweating if I was south of say New Brunswick to Trenton.

Reminds me of the Dec 2020 system somewhat. It won't be that intensity but it'll come down to it comes in like a wall or shredded. Feb's SWFE came in more like a wall and we had 4-6" for almost all. Dec 2020 came in shredded and it was still a very nice event here, but it was 8" vs 12+ because the shredded up precip shield allowed the warm mid level air to take over. We need this blocking to happen.

These move north at the end so many times. The soundings and 700/850 tracks will matter and whether the snow comes in like a thump or shredded crap. I'm a little hopeful for MBY 30 miles east of Central Park but if this blocking lets up by a hair it's congrats this entire subforum while I drown in sleet. Hopefully there's a way we can all win.

We'll see. That was a good GFS run. If this blocking really happens this can work out and we're getting into reality range.

That worked out better than I thought it would because the heavy precip came early before the mid level warmth could ruin it-in these SWFE type setups we need the heavy initial thump. Even in Long Beach there was 4-5" because the snow came in like a wall and piled up. The ones where it gets delayed/comes in shredded you know will disappoint.

It's really about the mid levels and 700/850 low tracks. Right now the blocking is stout enough that those don't screw us over but I wouldn't say we're out of the woods (around NYC). Look at the soundings. There will definitely be a sleetfest zone in this kind of storm because of those mid level lows going north of them and bringing in the warm air at 750/800mb. Right now that's most of PA down to Philly but have to watch any last minute trend.

Guardedly optimistic at this point. These shift north at the end so many times though. Hopefully the blocking does the trick.

This is where you have to look at soundings and the mid level low tracks-700 and 850. If those lows go north of you you’re essentially guaranteed to mix and there will definitely be a warm nose somewhere with a system like this and sleetfest zone.

Hey-if that holds we’re good to go. Hopefully that’s real.

I hope you’re right-hoping for an inch tomorrow so that would get me to 9” for the month, then this could add quite a bit if it goes well. These usually trend north at the end, we’ll need confluence and blocking to keep it south. I’d feel a little better about this one for Boston but we’ll see.