jm1220

If it totally covers the grass I’d call that something of a win. When we see these warm layers start showing up in a SWFE they 95% of the time happen. And at least sleet lasts longer.

The Euro might be too cold in a situation like this with strong WAA. Hopefully I’m wrong. It’s pretty likely at this juncture that at least NYC, LI and maybe close to I-80 get scalped for a while. Hopefully it doesn’t shave too much off but the NAM would probably be mostly sleet on the north shore and sleet to rain on the south shore.

NYC finished with 5” or so in 97-98 not 0.4”. The all time record is 2.8” in 1972-73 which would still be in danger if NAM is right.

Yeah if we get a shredded up initial burst, the sleet line will race north and we'll accumulate less anyway. If it comes in like a wall it will fight back the warm air for a while and accumulate faster. I'm never ever optimistic about SWFEs here as you can tell, but we do get the ones that can snow here every few years or so. It's been about 4 years since the 11/2018 good bust...

It has a nasty warm layer around 800mb overnight. It's worse than the other models but it'll likely be the closest to correct. NYC and my area at least would definitely be sleet on that and the south shore and East Brunswick area etc would probably just be rain. You're likely good.

Yeah hopefully its warm but I'm not optimistic when it usually sniffs out these mid level warm layers better. It flips essentially all of the city and LI to sleet pretty quickly with the warm tongue at 800mb. There may actually be more snow at the end as the coastal low takes over if it's right. Futility record would still very much be in play if it's right although maybe 1" or so would fall as sleet. If we see the sleet line surging north at us later tonight we'll know.

Don't see a huge change in the 6z models except on the southern edges where the meso models may be cutting back a bit. NAM still looks pretty lousy in general south of the favored areas in CT/upstate, hope it's too warm. GFS looked good. The southern edge south of I-78 and south shore is going to be the toughest spot where it could easily be some slush to rain if it ends up a little warmer. Almost nowcast time, I'd say we have until 12z runs to see what trends we have. The last second north bump is always a threat here and even my area/northern NYC has to look out for that. If you've been bickering and/or calling premature bust and wondering where your post went, I deleted it. Take that crap to banter or better yet don't post it.

We're close to nowcast time but I'd say we have until 12z tomorrow before we can breathe the "last second SWFE north bump isn't happening" sigh of relief. We're not at the range where HRRR and RAP are particularly useful. Hopefully the NAM is just a touch too warm at the mid levels, but it will almost certainly be more correct than other models. As far as I saw the other models basically held serve so far.

I'm not too concerned about it at this stage and it also cut back on precip in general which probably made it a warmer outcome. If the Euro cuts back a significant amount I'll be concerned but the other models seem to be holding steady. If this bumps back north at the end, no one should be surprised because almost every SWFE does that and it'll mean a lot for many of us since most of this subforum has no margin for error. I'm hopeful for a good event here but am totally prepared if at the last second it fails like the others. Just add that to the kicks to the teeth from this "winter".

Part of it's because there's less precip so less snow accumulating. Part of the nowcasting will be to see how the snow comes in. Less precip means the warm air has an easier time advancing. Also it might mean the coastal low gets going later which means the mid level warm air isn't shunted away.

The RGEM didn't look much different to me at all, minor differences that amount to noise. If we get shredded up precip, it's more likely there will be sleet or rain mixing in. The S shore and NJ south of I-78 were always going to be the toughest spots in this storm. No one should be surprised.

Yep, still the warm goalpost. Part of it seems to be too that the dynamics don't get going like the HRRR has so we have the showery crap precip shield that would be prone to mixing with sleet. QPF is something like 0.5-0.6 on the Nam vs 0.8" on the HRRR.

We could do quite well if we can keep the warm air away since we're closer to the developing coastal low to take advantage of some of the lift/frontogenesis that will develop close by, and not be hindered by the dry air further north. The south shore will be a really tough call since as you can see the rain gets close. We need to veer the winds ENE to keep the surface warming to a minimum which we need the coastal low for. Thankfully the primary low weakened from the mid 980s we were seeing a few days ago near Toronto to what you see there over Lake Erie. Not great but we can live with it if it's dying out and the coastal low takes over.

Wouldn't have it any other way that NYC is near the line between an impressive and practically no snow event. Your map looks good and I agree about that 1-2" notch you made into southern NYC. I'm hoping to make it to 4" IMBY. Anymore than that would be a big win. HRRR looked awesome though, hopefully that's close to reality.

0z HRRR 10-1 map (expect ratios to be more like 8-1 near the coast) and HRRR model snow map-more realistic. Either way impressive.

HREF looks good. 1-2” down to roughly I-195. 2-4” for the south shore, southern half of NYC and I-78 to I-80 roughly. 4-6” for northern NYC and LI (the LIE is the dividing line) and north of I-80, and 6+ in CT and Hudson Valley.

If we go to sleet in an hour I'm blaming your snowblower and will drive to Commack to sledgehammer it.

Where you are might be dicey especially if you're south of Sunrise Highway. That's like tier 1 of the area to get screwed. Tier 2 is there to the LIE, Tier 3 is north of the LIE and favored in winter events as much as anyone can be on LI. We want the coastal low to develop as soon as possible and veer the wind to more ENE so the ocean influence is lessened. And for the snow to come in like a wall. Showery crap will allow the air to warm.

All about where the sleet line makes it to, as usual. The dual pol radar'll be our best friend or worst enemy tomorrow night. NAM is more aggressive with the mid level warmth as usual but it can sometimes overdo it. If the coastal low takes over fairly early it should help mute the northward warm push. If we have shredded up precip the warm mid level air will have an easier time getting a foothold. And I do buy the big difference between south and north shore snow/frozen amounts here. Hopefully everyone gets a decent event and for most it'll multiply our seasonal snow total by several times or more so there's that.

GFS looks unchanged, maybe a little colder.

Surprised no advisory here. Advisory criteria is 2” or greater in 24 hours and officially the N Shore/NYC is above that?

We're likely narrowing the goalposts. At least there hasn't been a wholesale trend back north (though there's still time for one) and Euro held onto its cold solution. NAM is probably the warm goalpost and Euro the cold one. I think the John Marshall map makes sense. We want the snow to come in like a wall and not shredded so we can accumulate efficiently and not allow the warm air to surge in the lulls.

It might get Central Park over the record lowest snow. Snow drought being solved is still a looooong way off. That being said 3-4” here would be a godsend.

Good sign that the Euro isn’t ticking back north yet. If it’s this wrong this close in it has a major problem. We’re seeing especially in the meso models a significant south/north shore difference and I agree with it. The onshore winds are never good right along the coast and we have a marginal setup as is. This isn’t an especially cold airmass it’s coming into. If I had to guess I’d say an inch or so in Staten Island, southern NYC, LI and along I-78. Along I-80 and northern half of NYC and LI probably 2-4” and once you’re in the Hudson Valley and CT more like 4-7”. Usual caveat too about whether the snow comes in like a wall or it starts shredding up. If like a wall it’ll accumulate everywhere quickly and also hold the warm air aloft back somewhat. If it comes in shredded it obviously won’t accumulate as fast or at all if the coast is battling 35-36 degree surface temps and also the warm air aloft will have an easier time advancing in the precip breaks so when it does come down heavier again it might be sleet.

Even down here we've had some good April storms. 2018 was of course the mother of all late season comebacks. Up to 20" on 3/21/18 and 6" on 4/2 morning.