jm1220

Where does this come from? I've seen it snow in the single digits and accumulate like sand because at too cold temps the flakes start to resemble needles that don't accumulate efficiently. Lower surface temps don't mean better ratios. Why Some Snowflakes Look Like Needles - BelowClouds.com

About a 20 minute drive from the middle of Smithtown straight down 25. I agree, what we get won't be going anywhere for a good 10 days. It'll be a tundra.

Hope you're right and I'm wrong. I think we get 10" total snow/sleet. South shore 8".

It's advancing a little further every run. At 21z now it's sleeting in Staten Island and barrier islands, from the 0z run at the same time the sleet was around Perth Amboy. It still dumps a lot beforehand but it's noticeable by 10 miles or so.

What could make this a really great storm in Boston vs very good but not one of the greats is whatever happens on Monday with the coastal low. They'll also get assist from the coastal front. Pretty confident Boston gets at least 15" and good shot at 18. If the Monday snow happens they have a shot at over 20.

The resolution on the GFS sucks so it shows these weird blotches on the snowmaps. But I think from here down to DC are basically in the same boat. NYC probably does a couple to few inches better than DC because of closeness to the high.

I just looked at the 0z RGEM on Pivotal and not much change to me. Sleet is here by 21z and seemed to advance a little faster. Also it has something like 1.6" liquid now-whatever falls will be heavy with a lot of water content. This will be lasting a long time on the ground.

I'll probably get 2" more than the south shore because snow will hang on a little longer here but we see the colder models gradually adjusting warmer and the NAM/GFS getting slightly colder but no big cave. Pretty clear that we'll be sleeting by 21z. White Plains/coastal CT probably get a little sleet but not enough to really harm accumulations. So that could get them another 3-5" total over me. I do think 6" is a lock for everyone in this subforum save coastal NJ where we'll have to see when it changes to rain. Again, since sleet and snow are the same water content as all snow, it will just make it harder to move/shovel here and maybe we get some freezing drizzle to fuse it all together.

NYC/I-80/LI aren't getting 12" from this as much as I want it to happen. Just not the type of storm where it happens. Hopefully White Plains/coastal CT still can.

GFS looked a little better I thought. Still wonky/weird snow map due to bad resolution. Anyway from here I wouldn't use it anymore.

Reasonable, I predicted 9” for Central Park last night. 10” for the north shore, 7-8” for the south shore.

Yeah-if mixing is getting close to I-80 in PA here, it would definitely get to the city and LI. They will catch up to the other guidance overnight.

The snow depth might be counting the sleet that’s on the ground in addition to the snow. With the amount of liquid total vs snow amount it shows there could be 2-3” additional as sleet.

The 500/700mb setup matters most in terms of the precip we get not the surface (unless plain rain). This isn’t your normal heavy snow setup for NYC. It’s a typical Nina SWFE that has a better antecedent overrunning dome than normal putting more of us in the game for an initial thump.

The 12/26 clipper it overdid the mid level warming.

They could still be right. We’ll see what they say at 0z then I’d say it’s time to look at radar trends and start to buy more into the short range models.

I’m sure it’s somewhat excessive. It probably jumps the sleet line all the way to I-84 still. You can see how the amounts drop from Monticello area to I-84.

Well, if there’s 5” of snow at 10-1 ratio (0.5” liquid) then 1” liquid as sleet, that’s 8” total with sleet at 3:1 ratio. And again I don’t think this is gospel correct but it’s been consistent enough today to think it has to be onto something since it’s usually a little better at finding these warm layers, although it often overdoes it somewhat.

We’ll know in the morning as the snow shield comes into the area. We need the hellacious thump the RGEM models and HRRR/RAP show.

At this point the NAM is probably overdone a little with the warmth but it has something of a clue. I believe it more than the cold HRRR/RAP that I’ve seen come in too cold in SWFE setups.

It’s getting to the point where I start considering it. If other models trend south/colder tonight it’s onto something.

At 21z tomorrow it has sleet south of NYC still and keeps trying to wash it out as it advances. If that happens most of us will be very very happy. I’m still wary of it being too cold in these setups though.

Put all observations in this thread. 14 here currently, hoping I can luck out and make it to double digit snow/sleet combo. Good luck to all and may the yellow sleet line on the CC radar get curb stomped.

The heavy precip will help for sure cooling the column for a while but eventually all guidance gets the sleet line through the city and LI, probably by 4-5pm. Just north of the city it could go back and forth.

Yep, they still get the thump to start maybe 4-6”, but the easterly fetch eventually gets temps over 32 especially near/east of the Garden State Parkway. Interior S NJ might have an icing event since I think this surface cold will be hard to dislodge.