wdrag

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.

CoCoRaHs numbers. I'll add the two days up tomorrow and post a final on the associated threads. Ditto the NOHRSC interpolated snowfall which as of 30 minutes ago was still 12z.

CoCoRaHs numbers. I'll add the two days up tomorrow and post a final on the associated threads. Click the image for more detail. Now off line all day.

I tried the look up... couldn't quickly find what we both wanted to know. Still... there is no question this HREF is a good model. I also think the Canadian did well... NAM3K, not so good through the day cycles yesterday...actually disappointing.

I am definitely thinking HREF is the best... in short range. However not perfect. It lagged the past two events and yesterdays 12z is below. AXIS excellent but amounts a little low, probably due to banding,

So our CP 5.5+ will bring the seasonal total almost to normal for the season. ACY 4.2 raises their Jan to 17.2 or 3rd highest Jan monthly total and 9th highest monthly total in their history. Not bad for what was supposed to be a a weak winter. Suppose it can still go south but at least January is full of wintry opportunities. Enjoying every minute. Probably off line most of the day except for a CoCoRaHs post at 945A.

So the January thread possibilities. We've exceeded our 4" low threshold for a storm. I sure hope everyone is satisfied. AND, it's not a persistence month with December.

Wantage NJ 8 s High Point at the tippy top of the state... 1.8" 23.9F. still snowing at 645AM.

No Jan 15-16 thread til either late today or Saturday morning at the earliest. Still looks promising to me for a northeast USA snow and ice event but it could easily turn to just a cold frontal passage if the northern stream dominates. I do like the multi ensemble suggestion of something out of the Ohio Valley redeveloping mid Atlantic coast with high pressure to our north and leftover snow cover keeping ground temps cooler than without.

Have added the 5AM January 7 NWS ensemble probability of .01 freezing rain Sunday. These probabilities are quite high for a day 3 forecast. Not talking damaging to trees and wires but with the fresh snow cover, frozen ground and modeled dew points not exceeding 32F Sunday, ice looks highly probable, even to NYC-LI. Depends on timing. IF the precipitation doesn't arrive til 11AM or after in NYC (I95 to the coast) then treated pavements will be okay. Winds at the surface will probably be light southerly-southwest. This should ensure the LI coast to easily warm above freezing in the afternoon, if not during late morning. RGEM and NWS ensemble is the basis of this thread. The GFS still doesn't handle boundary layer temps very well. The EC looks better than the GFS but it too doesn't appear as threatening as the Canadian and SREF (oh no-the SREF?). Also: while the primary thread time frame is Sunday morning, it's possible periods of freezing rain can linger into mid afternoon along the I84 corridor hills which includes nw NJ/se NYS northern CT. Have even seen modeling turn this to a short period of light snow north of I84 but am not convinced.

Hope everyone is happy... it is beautiful. Nothing for me to add today-you have it covered. Overall thread works with ending times, and post event scattered snow showers or flurries as the sharpening 5H trough passes through this afternoon. Wantage Nj at least 1.5" but I95 corridor has bounty!! Yay! New ICE thread starts by 630AM for Sunday to include NYC.

Wantage NJ 1.2" at 410A S-. 24.3F Light north wind.

This shares my concern. I'm pretty sure we ice to about I95 Sunday morning-midday with sleet nw of I84... possibly ends as a period of snow sometime later Sunday near I84. My guess because of new snow cover, our grounds temps will be easily subfreezing and that puts us in line for a widespread light southerly wind icing event. The only good news, is that midday insolation will assist melting of ice on pavements. Still, I could see up to 0.2" of glaze on terrain near and above 1000 feet. Right now I'll wait til tomorrow morning to thread, if it at that time looks even more likely to occur to I95.

Adding some baseline graphics from 12z-21z/6 guidance that tries to frame a realistic outcome of this event. Snow begins ne PA/extreme nw NJ 10PM-midnight and overspreads all of our area by 230 AM. Bands of heavy snow with around 1"/hour rates should develop in central and northern NJ between 3 and 4AM and become dominant across LI into southern CT between 5 and 7AM. It ends from southwest to northeast between 8AM and Noon across our NYC subforum. Scattered gusty flurries or brief snow showers could continue into late Friday due to steep and still somewhat moist lapse rates associated with the short wave passage. Cleanup should be swift shortly after the snow ends. An 850 MB low will try to get going south of Long Island near sunrise Friday which should permit the overall heavier snowfall from this intensifying coastal low to occur in New England, possibly back to eastern LI. High impact event for the morning commute--- should result in delays/cancellations of some morning activities. IF you have to travel, allow plenty of extra time. 1) NWS 5PM collaborated snowfall graphic. 2) NWS 5PM collaborated Storm Severity Index. 3) SPC HREF ensemble forecast snowfall (12z/6) 4) 18z/6 NAM Banding potential--see black areas for generating bands of heavy snow near 4AM 5) 18z/6 NAM Banding potential--see black areas for generating bands of heavy snow near 7AM 6) NWS 21z/6 ensemble chance of 2+" of snow. 7 NWS 21z/6 ensemble chance of 6+" of snow. Note the ensembles are not quite so bullish on 6" amounts. Do enjoy whatever we get... this should be fun for a little while.

OBS NOWCAST thread should be up around 735PM. Working on something for Sunday...just needs more review time 830 or 9. Nothing on the 16th-21st yet. Need study time. Enjoy every minute of this beautiful upcoming morning snow. Walt