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So the 12z/9 GGEM is consistent, certainly I84 corridor for a wintry event. Will check 12z/EC and ensembles and if EC continues on with wintry LI north, and 18z GFS backs off the Thu-FRI closeness and heads more toward late Sat-Sun night...then I'll start the thread at 9PM. No insight. Walt 1204P/9

Wantage NJ 740' MSL going ups degree an hour and 28.8 at 939AM. Ice even on shoulders of treated roads.

Freezing rain sprinkles have occurred Wantage. 27 at 714A. Manageable where treated, except a more careful approach I84 corridor. Not like Wednesday morning for NYC, I95.

No thread from myself on Sunday the 16th potential event. I don't think the 00z/9 EC op very close to the coast is the most probable outcome but respecting that this might yet be only I84, holding off. GGEM continues steady for a snow event. Will reevaluate for a thread at 8PM today or 6AM Monday. Looks like a nice winter pattern for the rest of January to possibly hold onto snow cover wherever its more than 3 inches deep this morning.

Likely my last post for the evening. Watch IPW-ZRW- showers, sometimes it ends up south of modeled. We'll know more in the morning. 21/12 at the house in Wantage at 751PM with a light southwest wind. Often 23F at the surface or 23F somewhere in the sounding below the above freezing layer means sleet instead of zr.

No thread from myself this eve. will revisit either Thu or Sunday events in the morning. First up: Ice, at least I95 west.

4 consec cycles of op EC producing spotty or greater coverage of 2" snowfall on LI. 2 consecutive GGEM runs of a winter storm for the northeast. I'm close to a thread centered on the 16th but need time to review ensembles. So either start it at 9P tonight or 730A Sunday, if the 00z cycle continues. Very broad ballpark wording (kitchen sink) that will permit honing in more likely solution with a solution from ice/rain to a snow event of varying unknown magnitude. That's a D8 risk so keeping this in mind. My feeling is we've already had a fair amount of speculation and I don't see it ebbing, yet. Later, Walt

Will probably convert this thread at 9PM to OBS-Nowcast with same headline.

Thanks for the feedback... I'm un sure of NOHRSC practices but am sure they use filters and the longer we wait after the event ends, the more complete the data set. We in the NWS could produce these types of maps back in 2018, but it's a bit time consuming ensuring the data is correct. Staffing and other priorities may preclude?

Wont be posting 345-630PM. What a mess coming tomorrow. Added the 12z/8 SPC HREF freezing rain, and the HRRRX freezing rain. There probably will be a relative dry slot tomorrow morning, where only T or .01. and some of these modeled amounts may end up sleet. Still, pretty impressive. Also i checked the HRRRX PTYPE at 18z (1PM) Sunday... still freezing rain much of the interior 20-30 miles nw of I95, presuming it's precipitating.

and now the most bullish model from the 12z cycle: the HRRR... Pretty interesting and there are now model hints that icing lasts into mid afternoon parts of the distant nw suburbs. Also, keeping in mind the HRRR tends to be a warmer model of the suite, certainly warmer than the RGEM and NAM.

SD is reported in whole inches... 4.7 rounds up to 5.

This ended up small northwest, moderate I95 corridor to a heavy but not extensive major event (1 foot) for the eastern edge, particularly LI CT. Occurring basically in 7 hours, the rate of fall was intense. Snow water ratio's added beyond the typical 9-11 to 1. CoCoRaHS sampler two day amounts as of 915A, the NOHRSC assessment, the NAO and PNA values during the event. Lead time by the models good, thread was underplayed LI.

Here is the wrap up...CoCoRaHs and NOHRSC analysis. Hopefully this is acceptable. NAO and PNA indicies at the time. Click for details.

06z GEFS snowfall... definitely stepping up amounts next weekend. Small but noticeable.

I'm no longer up to speed on ASOS snow melt but I agree it could still be a problem. I just want everyone to see those indicies where these events occurred Jan 3 and 7 and again, helpful NAM Banding guidance showing potential 1+"/hr.

No one should be surprised if this happens at 7AM, per RGEM and now the 06z ECMWF.

Opportunities...which if any will produce more than an inch of snow or .02 ice? I do think the northeast USA should be happy with the +NAO -PNA producing what it has so far... not too shabby. Indicies good for patterns but part of this is timing.

Next snow's: Small chance a period of snow around Thursday the 13th. Bigger chance sometime between 15th-17th. Am pretty sure (60%) there will be snow sometime between the 15th-17th, even LI, but are amounts less than 2" or do we find ourselves with another decent 2+ event. Modeling has not been excited about anything the past couple of days, I think in part because of how Thursday resolves, especially with it's potential interference developing low pressure off New England. Just need to wait it out

Will add CoCoRaHs two day around 10A and probably repost these graphics below on the initial thread for review. In essence... our first week of January snowstorms in the northeast. No negative NAO and no positive PNA. The indices are nice but I still think it's location-location-timing-timing. Anyone look back at the NAM banding graphics for S+. Pretty interestingly accurate.

The advisories were issued this morning to just about I-95. It's a matter to details and any eastward extension. In my opinion, I think we'll need to see an extension into western LI to near Islip and all of southwest coast including Stamford-Bridgeport, but that is only an opinion based on EC/RGEM from 00z-06Z and I could be wrong. It's light but a problem with frozen ground and subfreezing temps to start the day. Other issues: How much wind-mixing? I have my doubts regarding temps rising above freezing in the I84 corridor hills (extreme nw NJ/Poconos/se NYS). Then, when another short duration period of rain comes along around sundown, it could be more icing. Finally, it clears overnight Sunday night but if the wind doesn't mix down to dry out the pavements, it could re-ice. NWS ensemble chance of icing...if you use this, check the legend for the probabilities. BOS-NYC-DCA on the edge... can go either way.

One platform view of snowfall analysis. Imperfect but a decent idea.

You'll probably disagree with so few higher numbers. I know I had 1" less than interpolated, but this more or less outlines what happened.

No, it is the Canadian ensemble.

Regarding next weekend: 12z/7 GEFS and more so the EPS are soft on the trough and so not much going on, whereas the GEPS is telling us be alert for an enewd moving low through our area. Outnumbered 2 to 1 No thread, yet. Part of this potential is related to how a southwestern USA trough lifts out and merges with the northern stream or does the northern stream (GEFS/EPS) leave that sw USA trough behind? Will look at it again tomorrow.