wdrag

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

Good morning everyone...just a note on threads. Will begin the OBS thread at 8 or 9P tonight. Am looking at threads for Sunday the 9th which is trending colder - ice and or snow along or just northwest of the I95 corridor westward (too warm Long Island I think but time to change), and then the following weekend (15-16) but absolutely nothing from me til Friday or Saturday on those. Am off line til at least 6PM. Have a great day!

Good Thursday morning everyone, I'll start an OBS-NOWCAST thread at 8PM tonight. In the meantime--it's coming. What do I think from looking at op models and ensembles? 2-4" nw NJ and 3-6" elsewhere with nuances. You all will be on top of model guidance and your own sense of what will happen. I'll get into the banding with the NOWCAST thread this evening and haven't examined that nor snow growth but it seems to me NYC should receive 3". I could be wrong, as usual. The storm continues to be a 5-10 hour event (midnight-Noon) with ending time most of our area 9A-11A, though a few flurries should be scattered about through the afternoon as the sharp cold 500MB trough passes through. Added the NWS 5AM regional snow forecast and the Winter Storm Severity Index. Use the legends. Delays and/or at least some morning activities cancels anticipated in my opinion. Am looking at threads for Sunday the 9th which is trending colder, and the following weekend (15-16) but absolutely nothing from me til Friday or Saturday on those. Am off line til at least 6PM. Have a great day!

Seems like we've evolved into a seasonable January around here with snow and ice opportunities and possibly some consensus on western ridge,eastern trough for at least the next two weeks. Both GEFS/EPS have been showing low pressure off the coast in the northeast Jan 14-16 for the past two days. That may also be an opportunity for a fairly decent ne USA system as the 500MB trough tends to deepen westward with short waves dropping down the western NAM ridge into the eastern USA.

NWS 5AM deterministic forecast.

I'm a little cautious. Checked some 00z guidance, banding, DGZ... I just wish we had more 850 low development further south. Seems to me like a 5-10 hour event.. Good short wave, but little inflow and certainly no easterly inflow at 850MB, at least not yet. Banding possible could enhance snowfall. Too early for me to be sure where. EPS-GEFS from 12z/4 and 00z/5 were timid. There is time... and NYC-LI you should get your first solid inch. Here's my take for the forum not reviewing 06z 3KNAM Banding. Midnight-Noon Friday: A 5 to 10 hour period of snow occurs from northern VA through Baltimore, PA/NJ/NYC and the I84 corridor to Boston. Amounts should be in the range of 1-5". Uncertain where the heaviest occurs, though tending to favor coastal NJ through NYC and especially CT/MA but this could be wrong. All untreated surfaces will be snow covered and slippery for a few hours near dawn Friday, so prepare for some delays in snowy conditions. Snow ends Baltimore around sunrise, ends NYC/nw NJ/ne PA 9-11A but for Boston it may linger til mid afternoon. Added three graphics generated around 4am today: showing the chance of 1" and 4+" and the Winter Storm Severity Index. We can add the regional snowfall forecast by the NWS when it updates at 530AM. Adjustments in amounts and ultimate heaviest axis will need to be further reviewed-changed. We'll have the SPC HREF at 11AM for a first crack up to 7AM Friday. Added NWS snowfall forecast as collaborated through 5A today.

Showers are moving northward into our area and with frozen ground and subfreezing conditions, it could become quite slippery on untreated surfaces in some spots along the I95 corridor just southwest to north of NYC. The National Weather Service has advisories posted. Added NYC 550AM as well per obs below. Also some snow mixed at the start nw NJ thru se NYs, W CT, WMA.

If the banding is there for 6 hours, you get as yesterday 1-2 inches/ hour and thunder snow. I have not looked at any 12z guidance. I guess fast moving will cap max amount at whatever value but if this times with the morning, there will be big impact. Note yesterday Fredericksburg. Also this argues my own bias to prep early and that all of us understand in advance the consequences of eliminating the broader range of possibilities. Off line now through 5p. Have a day.

I know there isn’t much stat support but these Day before near record warmth followed a day later by a snow storm, in my opinion are not uncommon, and associated with leftover Large PW near the front and an oncoming intensifying short wave.

Modeling is tending to try for a neg tilt intensifying nor'easter. Best snowfall north of our area since ensembled 850 LOW is still north of us. Added 00z/4 GEFS spaghetti and NWS ensemble chance of 6". THIS DOES NOT INCLUDE guidance after 12z/Friday. The idea Is I95 could serve as a mix boundary? Something wintry is coming, especially interior.

Also, Correct me if I'm wrong: Atlantic City calendar day snowfall yesterday was their 7th highest in their period of record.

Adding on: I saw a gradient of 8" over 32 miles: between Brick 2" and Barnegat 10... or 1" every 4 miles traveled south/north along the NJ coast. That's an approximation but does indicate the sharp cut off south of I78.