jm1220

For mid level temps I’d use the NAM or other meso models. GFS is normally too cold there. And as others pointed out the warm layer in these events is often above 850mb so you can’t rely on that for snow/sleet line.

Wow, poor Boston if this becomes mainly NNE for snow. Some sleet would be good I guess but I’m fine with a washout if it means no ice storm and snow is out of the question.

Once in a blue moon we can pull a decent SWFE out of the hat but these are usually easy ones to call for around NYC. Sloppy mess to rain, more icy inland where cold surface air holds on, up near I-90 gets the real snow.

Those are overdone. Pretty sure it assumes any liquid that falls at 32 or below will accrete (not happening if it’s moderate or heavier precip) and all the precip over that hour will be freezing rain. The FRAM charts are more accurate.

Definitely a better winter where I am but overall the places that jackpotted last winter are getting skunked. Now we’re entering a more typical Nina pattern where New England gets the SWFE goods. Hopefully I can get one more decent event to get me above average. I have 29” and average 32” or so. Last winter I had 42-43”.

Interesting trends so far tonight. Hopefully the colder outcomes happen and we don't see the usual bump north with SWFEs at the end. I don't buy it being more than 2-3" of snow to start around the city but it can be that to a ton of sleet and then a drizzly dry slot. If you're north of 84 you're still in a good shot at 6+.

I can actually see it not changing to plain rain for NYC and much of LI until perhaps the end or as a dry slot comes in. By that I mean there’s plenty of sleet and some ZR but it’s cold enough to start to keep it non-rain. Unfortunately for snow you want to be in Boston or north of 84. That’s been the case for days and won’t be changing much.

If there’s no mechanism to bring warm surface air in from the ocean, from an E or SE wind, it’s hard to see how we go above freezing. If the cold NE wind stays for the storm I think most of us would stay sleet or go to sleet/ZR. For snow though since the mid levels usually warm up faster than modeled at this stage and the tracks are lousy for us, you’d want to be north of I-84 or preferably along I-90.

Some models are showing a heavy ZR area near the city and north shore especially. RGEM would be an ice storm warning level event.

It’s at the time of year where urban heat island will hurt, and the cold air is generally coming from the NE, so this is a rare setup where it can snow more on the Forks than NYC.

Yep, starting to look like it could be pretty dicey especially the northern half of the city and LI north of the LIE. I’m still not expecting much snow but could be prolonged sleet instead if the surface front can stay offshore.

But so far. It’s the story with 90% of SWFEs here. I-90 is the spot for this one. The real questions for us are how much is sleet vs rain and can we get an hour or so good snow to start.

Well no, but this is a fairly easy one to call for us. Hopefully the few hour thump to start but expect the sleet and rain to dry slot. NYC can cash in on any setup, Miller A El Niño event like Jan 2016, Miller B event like 12/30/00 or the events last winter or 2/25/10, but we also get the lousy end of all of the above if the confluence is too strong or too weak or etc. We have no bread and butter event like Boston or DC. NYC is the toughest I-95 megalopolis city to forecast for during winter.

Yes-it was an overrunning event for the first part on 12/5 that was supposed to be maybe 1-2” to rain, and it ended up being the best part of the overall event around NYC. The rain line got to around Sandy Hook and stopped dead. The coastal storm redevelopment on 12/6 did a lot better in Suffolk County and there were parts that had 20” overall. Long Beach had 12-13” I think. 8” from 12/5, 4-5” from 12/6 because the coastal storm hammered Suffolk County.

Onshore flow isn’t a killer this time of year I’ll say that. VD 2007 would have been a washout for the city on east if it was 12/14 any winter.

It can happen in the right situation. 2/22/08 is around this time of year lol. 12/5/03 is the gold standard. But it’s 2-3:1 for these to be lousy sleet to rain events here while it piles up in Boston because of a lousy high or charging primary that doesn’t transfer in forever.

Pretty sure it’ll be an event where we hope for a pounding when the mid layers are still cold enough that can add up to 3-5” unless the evolution changes drastically. The real goods will be Boston to Buffalo. And hopefully the high doesn’t back down or become one that scoots out as soon as the WAA starts. These SWFEs have to evolve perfectly for around NYC to do well.

Yes-I never look at those maps other than for lols. At least that map gives the disclaimer.

3:1. 1” liquid=3” sleet. I’m not totally dismissing the GFS either but I’d wager pretty big that it’s a good bit too suppressed and cold, and that NYC would get a lot of mixing with a setup like this. This looks like one of the 07-08 SWFE events that ended up clobbering I-90 and we hoped for a few hours of heavy snow to start. It does work out sometimes like 2/22/08. I’d like to see a lot more confluence in place to force the redevelopment south enough to keep us all snow. Right now I don’t see it there and see it being a more typical SWFE outcome. And we’re forgetting how way much warmer the Canadian is, although that might also be overdone on the other end.

That map counts sleet as snow. I'd be stunned if S NJ and Philly are jackpotting in a SWFE.

S+ and gusty winds. Quick dusting on my deck/grass.

Way too early to pin down but the mid level low tracks are key for who and how much mixing happens. If the 700/850 lows go NW of you, there will be a lot of sleet/mixing. For most of the storm to be snow anywhere you’d want those lows to redevelop south of you.

GFS is interesting but as others pointed out likely too suppressed. These storms highly favor I-90. Hopefully we pick up a few hours of heavy snow to start on the front end but unless there’s a major change in the evolution it looks like a fairly typical SWFE heading into a strong high to me. Thankfully at this point the warm ocean isn’t the kiss of death near the coast it would be in December so hopefully most of the storm wouldn’t be a washout.

Decent burst here a couple minutes ago. Too warm for any to stick however. Hopefully some of these squalls make it here later.

I gave into that, my bad.