jm1220

Download RadarScope and use Correlation Coefficient. The yellow line is where sleet mixes in. This was as of a few minutes ago

That stuff over SE PA will pound us for a few hours.

FWIW the 3k NAM has sleet to Staten Island by about 2pm over to I-80 in NJ and to the Tappan Zee/my backyard/West Milford by 3pm. It's quite wet, 1.5" liquid or more for most.

2.5" here just about.

Doesn't look like it's moving north all that fast over DE and hitting some resistance over DE Bay. I'm sure it's still coming but time to watch the radar and the CC line from here IMO. And heavy enough rates can overcome a very shallow warm layer a little above freezing which is probably what the HRRR is showing with the fighting back and forth.

I think there's a freezing rain zone later just a little bit inland in NJ, hard for me to see how this kind of cold surface air gets dislodged. Still in the mid teens there.

Thankfully the Austin TX area which I'm very familiar with got mostly sleet with some ZR. Would have been devastating if the 0.5" liquid fell as all ZR. It was kind of a crap shoot as to whether the cold surface air would be dense enough to refreeze the raindrops. In the areas where not, it was clear this would be a devastating event in places.

Heavy snow rates=warm air advection. Not surprising to me, we just have to max out what we can while we have the cold enough mid level air. It’s a SWFE and these type of storms will always behave accordingly when we have retreating confluence. Enjoying the heavy snow and closing in on 2”. Should end up with 8” at least before sleet which should add up to a couple more inches. A little freezing drizzle to freeze it all up and weenies here will be happy for a long time.

It seems more NW/SE oriented with the mix line so far and even the HRRR now gets sleet briefly into Rockland/N Passaic before it mixes out, then it seems to fight back and forth for a while even into northern NYC/North Shore. I-84 which will be a little north of the mixing over to Boston which should get additional snow on Mon with the coastal storm will be the jackpot axis here. But that doesn't lower the impact here or where it mixes for a while IMO since it will all have the same water content.

Pretty sure they don't. On the NAM at least I noticed that once the sleet line was through it stopped adding snow. Like it or not the warm mid level thermals group seems to be winning out. The NAM's been steady enough with it that it's clear it was onto something. But it won't matter if we get upward of 2"/hr before the sleet and a couple inches of sleet on top with some freezing drizzle to cement it all up. It'll suck to shovel/move it, roads will be horrendous because sleet is a lot harder to really get rid of and it will last way longer because it'll turn into a brick.

High end moderate here, looks amazing. The ratios will lower to close to 10-1 as the warm mid level air comes in but the intensity will increase.

You'd have to check the soundings but the sleet line's coming north pretty steadily. Gets held up here and there but no major issue I can see vs guidance. We have until 2-3pm to really clean up (around the city), maybe 4pm for Suffolk County. New incoming 12z HRRR gets sleet into the city/I-80 around 3pm and east from there to most of Suffolk by 4pm but it fights back and forth for the northern part of the city and LI for a time. Hopefully those fights back and forth can buy us another inch or so. At the end of the event there should be some freezing drizzle in the dryslot before it all freezes up. This will be really bad to try moving. Might be a good idea to shovel right before or as it changes to sleet.

I cashed out from NYC and put my money into yes for 20"+ in Boston and a little on 24"+. I'm thinking under 10" too especially how they measure but it should really rip until 2-3pm when sleet will barge in. And then it's a question of how much QPF as sleet, that counts too.

Just over 1" here.

Yep, we're gonna have fun the next 6 hours.

It's going to be a fun few hours before the sleet gets here. Could be 2+/hr. Let's hope anyway. I just don't buy that south of White Plains it won't be all sleet for a while. Hopefully I'm wrong.

Figure out a way to get a day off and jump on the Acela.

Snowing here, dusting on the ground.

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.