jm1220

Oh man am I praying.

I’m hoping for the freezing drizzle at the end-maybe it happens in the dry slot when there’s little lift. It’ll encase everything into a glacier.

Take the betting stuff to banter. I get it lol but keep this for storm discussion only.

Back down to 14.

Very dry air though. Dewpoint is -11 at JFK.

It has crappy resolution which results in the weird snow map outcome but it doesn't have a heavy consolidated snow shield like the RGEM group does. Has an inch per hour maybe which is moderate snow.

The nature of this storm is pretty clear that New England would get nailed a few days ago. It was pretty clear to everyone this wouldn’t end up a VA/Mid Atlantic snowstorm. Retreating high, retreating confluence, trough in the west and SE ridging=SWFE that favors I-90, Boston over to Albany and S NY. The initial high pressure/overrunning gives people like us down to DC a fighting chance but the best is along I-90. I-84 should do very well too.

Starting to get to that point but I’d say tonight we pay more attention. In any event we’ve seen the HRRR gradually getting warmer although still impressive at 18z.

Looks lame/warm again like 12z. If we’re punching sleet up to I-84 here, people near the coast might barely eke out a warning event. Hopefully tonight 0z we resolve this one way or another, if not we watch the radar in the morning to see how the snow advances in. That’s really the difference maker here.

Shoulda woulda coulda?

Winters for the last 20 years in Central PA have by and large been horrendous. I’m glad that most of that region should do well tomorrow but the long term average for State College, Altoona, Williamsport etc is over 40” snow per winter. They’ve been able to manage that in their few high end winters in the last 20 years but by and large way below that. Way too many SWFE’s that turn into sleetfests, cutters or Miller Bs that develop too late, much fewer Miller A coastal huggers like 3/1993 or storms that would redevelop offshore in time-now these are good I-90 snowmakers not I-80. It started right when I went to school there and never really improved. So I’d say there’s definitely some long term shift that’s screwed them over and not some short term correction that will easily reverse.

Hopefully tonight's 00z gets better, then I'll start to legit worry it's onto something. I consider this the low end and RGEM the high end if all goes perfectly. This run looked maybe a hair better but all in all still sucks. Tough forecast for NYC because it's really a couple hour difference and intensity of the initial snow.

Looked maybe a touch warmer to me. Sleet gets here by 22z roughly.

Unfortunately with the late developing coastal, you have easterly winds for a while which warm up the surface.

The posters from coastal NJ south of maybe Asbury Park yes since there's an easterly flow established, otherwise no.

Would just make it a gigantic glacier. Even if we have a period of freezing drizzle at the end it will fuse everything together into concrete.

I’m thinking 8-10” total where we are, have to hedge lower with the NAM as crappy as it is and GFS cutting back. Hopefully the snowy models have a clue.

We did pretty well last Feb with that smaller SWFE when the snow came in heavy right away. Same with Nov 2018 which was completely unexpected. This will have a larger overrunning surface which means theoretically a longer duration of snow. But we really have to see how this evolves overnight/in the morning. We’ll do well if we have heavy snow echos coming in like a wall for hundreds of miles to the south. If we have spotty in some places heavy snow in some places light and dry holes thrown in, we won’t. And the sleet will take over sooner.

Yep, 2/13/14 for example I don’t think was a rapidly intensifying coastal and there was widespread 10-14” amounts.

It’s not going to rain on LI (plain rain) outside of maybe Montauk. This kind of cold surface air won’t be dislodged unless we had a strong prolonged onshore flow. I could maybe see freezing rain for a time but the back half of this storm is probably sleet. NJ gets that prolonged onshore flow so south of Tom’s River it might really change to rain.

Hopefully the ratios start out above 10-1 when the column is still cold, so maybe we average out 10-1 before the sleet comes in. Some places north and west that stay all snow will likely average 15:1 type ratios given the amount of moisture in the snow growth zone and lift.

I’m not sure of the exact algorithm but it’s supposed to print out predictions based on analysis of similar storms in the past and gain experience and therefore better predictions in the future based on verifications. I’m sure it would evaluate similar patterns at 500mb, analogs etc to come up with the predictions. I’m not sure how it directly evaluates current atmospheric conditions to come up with the predictions but it seems to match up pretty well with the operational EC.

Well-it either scores a coup here or falls flat on its face. It’s supposed to build better results with experience-not sure how much it has with setups like these. It did pretty well with the Dec storms.

NYC only had 7-8 inches from 3/14/17 but there were snow/ice mountains everywhere and streets were horrible as if way over a foot fell. I remember how bad it was driving down some side streets in Queens. The 7-8” NYC had was the same water content as someone in PA that got 20”+. This one won’t have the same water content (I think over 2” liquid) as that storm but it will still be significant impact.

Exactly. 7-8” of combined snow and sleet will be a PITA to move to put it mildly. And that seems to be the low end.