eduggs

Northeast of you and a bit lower in elevation. I don't love publicizing my town on a public forum

The latest HRRR does sink the mix line down a little this afternoon! That could really help NNJ and northern Westchester pick up an extra inch or two this evening and flush the sleet vibe. It continues to look sick for Orange and Putnam on north!!

Looks amazing for Orange, Putnam, and Dutchess. Even has lingering wraparound into tomorrow.

I think the NAM has been great - just like with Dec. 26. Thank god we have the NAM model. Otherwise people would have been thinking for days that we were getting 18"+ (i.e., Apple Weather App). People think the Pivotal clown maps are the NAM model. They're not. The NAM forecasts QPF and temperature. How other people (pivotal, TT, even Bufkit) calculate snowfall based on that is separate from the model itself. This morning we've had a slight overperformance in terms of QPF and really good ratios. But the NAM has clearly been the best with the mix line.

We saw heavy rates overcome a shallow layer in Little Rock yesterday morning. But that sounding didn't punch through with +3C like this afternoon's forecast sounding looks to.

4.25 new in central Morris County. Temp steady for the past hour at 9.4F. In a bit of a precip. lull relative to earlier. Still probably 0.75mi vis.

Check the MA forum. They're saying it's really not accurate. Mix line way north of that.

That's fair, but here's 3pm near Newark. That's a sleet sounding. So presumably sleet started before this time period. Obviously the further north you go, the later this sleet. But it definitely looks like it's coming quickly. That's why I'm heading outside now to enjoy it.

Who likes rain in the winter, are you crazy? I'm obviously rooting for snow and only snow. I'm heading outside now to enjoy it. It's perfect out right now. I'm not looking forward to sleet this afternoon.

I'm extrapolating when areas further south started mixing with sleet relative to the HRRR. The mid-level surge is really strong.

I think we have about 4 hours at least to do it. Although sleet could add another inch+ thereafter. Might be able to do it.

The NAM and GFS seem okay on Pivotal, but the UKMET seems wrong. It keeps adding snow after the mix line moves well north. The ECM-AI is also obviously way too widespread with snow accumulations but I think that's due to lack of vertical resolution. A few other models might be off on Pivotal too - it's model by model.

Ugh, the HRRR has sleet in here by 1-2pm. It has continuously shifted north since it's been in range. And sleet actually started to mix in in VA earlier than the HRRR showed. The northern edge of mixing might oscillate or battle back to snow but that's quite the warm tongue surge now modeled.

I wish that were true, but it's not. Regardless, even if it is/were true, that's what the "mix line" means.

A day or so I highlighted northern VA as an indicator for how well the models were handling the sleet line. The warmer models surged it to northern VA before 10am while the colder models kept it in southern/central VA. Looks like the warmer models were right so far. I really hope it shifts east and washes out this afternoon. Without looking at the latest model runs I'd gotta assume someone in the mid Hudson Valley could hit 18" today

The mix line is through the the DCA area. The graphics for the colder models (e.g., UKMET) had it well south of there at this time. The snowier models (ECM-AI etc) that showed 10"+ down that way are not likely to verify. Most reports are around 6" or less of pure snow. They should get a few inches of sleet on top, however (which Pivotal claims not to count as snow).

I hope so. It looks amazing outside right now.

Wow off to a fast start! Intense overrunning with lift through a deep layer encompassing the DGZ is magical. A quick switch to heavy rates probably means quick mid-level warming, so let's get outside and enjoy this!

This is questionable. See DCA as an example below. At 18z Sun the 18z UKMET shows 7.7" snow accumulation. The ptype is sleet and the sleet line has cleanly crossed the area. By 21z the sleet line has crossed into PA indicating the line was advancing steadily northward. Yet at 27hr the UK snow total on Pivotal increases to 8.9" for DCA and then 10.3", and 10.4" at 30hr and 33hr. Based on this continued snow accumulation when the dominant ptype is clearly not snow, particularly combined with the mismatch between the UKMET snowfall output compared to other models, the claim above seems dubious. Something is not right with the way Pivotal depicts snowfall accumulation for the UKMET.

The RGEM has several hours of rain on the eastern half of LI overnight Sun - especially south shore. Anybody buy that?

The 18z RGEM is the best run I've seen in a while from any model. Very impressive thump with several hours of 0.1"+ liquid and it shifted the sleet line meaningfully south! Unfortunately when the 3rd party graphics for the RGEM and NAM differ with northern extent of sleet, it's usually best to go with the NAM. But a shift south is still welcomed.

Unfortunately the ECMWF-AIFS treats all frozen precip. (e.g., sleet) as snow in its 10:1 total, so that map isn't going to tell us much. Same is true for the UKMET and a few others.

Right now the model consensus has the dividing line between big snows and more modest snow accumulations plus sleet from extreme northern Morris County through northern Passaic, Rockland, northern Westchester, and northern Fairfield. Right now I would take the under on double digit amounts south of this line. Hopefully the last two model runs and then nowcasting shift that line south a bit.

Don't tell everybody Don't make them wise. Lots of money to be made of these hyped events