jm1220

Euro once again too cold in a SWFE 2 days out but hopefully the front end thump idea happens.

So far I’m glad the 12z models got a little more encouraging but it’s a nowcast situation with this IMO. Hopefully we don’t see the sleet line racing north tonight.

HREF essentially a carbon copy from 0z-4-6” for most of the city and LI, 2-4” extreme S shore, 6”+ for most north of the city. A little surprised. Hope it’s right.

It’s maybe a little better for the immediate coast since winds veer more easterly then ENE into the event but if the snow breaks up, could be dealing with 35-36 and trying to restart the snow/accumulate which will be very hard. Eventually warm mid level air probably will make it in which means it goes to sleet or more likely rain. That’s why these maps showing the N to S shore accumulation contrast make sense. On the N shore and just inland temps are near freezing or a little above which makes accumulating a lot easier.

It’s why I haven’t even commented on this storm yet. It’s impossible to be excited about anything more than 4-5 days out. Maybe the confluence can press it south but the SE ridge is going to try and make it cut. I plan to enjoy whatever falls tonight/tomorrow and hopefully at some point by the end we can get a little more.

Held steady. Hope it’s right.

Your dew point is 18.5 so when precip comes in it will cool down quite a bit.

Another reason we want the snow/precip to come in like a wall.

I don’t think rain will wash away what falls at least away from the Rockaways. Might change to rain but 2 or 3” will stick around into tomorrow.

Has more of a front end burst which helps a good amount. It still warms up the mid levels overnight and flips us to sleet. But after a few inches falls already.

Hopefully you’re right and it would also help keep the warm air at bay for a while.

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.