wdrag

What follows is knowledge 4 hears ago, and I wonder if it's advanced very much since then. NWS uses snow ratios, usually in 3 hour increments... not a finished science but an attempt at improving upon standard 10 to 1's. They can break it down to 1 hr increments with the associated hourly qpf and weather grid. Then the automated conversions occur. VERY VERY busy within 72 hours of an event to try to get this right for the WFO, then to collaborate it among the adjacent WFO's and the WPC Winter Weather Desk at NCEP. They usually have 30-60 minute conference calls at about 1A/1P if multiple WFO's on a warning event (ECWS) for snowfall and when to trigger watch-warning process. It is my opinion that BOS, followed by PHI led the way from DE to New England. It is also my opinion that there is a conservative approach with so many millions of people involved in the Response. No one wants to be wrong. I do think the science has potential to advance (as this forum showed) for big ECWS beyond 60 hour watch process. It will help when the model science can show greater consensus further out. I think the GFS held the NWS and others from giving stronger alerts sooner. I also guess not much damage done on the shorter term alert. We won't know that behind the scenes EM/FAA discussions if they are required. NWS always looking to improve it's processes, but it's slow... So many folks tuning in to forums and other resources well before an event is officially acknowledged. Just the way it is... Have a good finish to the storm.

Nothing to add. Plenty of excellent info posters - model guidance shared among all. Just no time in my life. i started posting near the time of Covid furlough. That ended 10 months ago and this just takes too much time away from family etc. Excellent forum--- excellent contributions from all. Hope everyone is pretty aware how good the Canadian models were against everything, how woeful the GFS til 00z/28. Always need the Canadian on board for decent snow. EC wasn't too shabby either, with equally fortuitous prediction aka the GGEM. Have a day.

Just posting obs... keeping my FB group up to date but just don't have the time for all the effort needed for the forum. Enjoy the snowstorm.

All good as always. Thank you... 2.9" at 9A still snowing 1mi at 1022A

Wantage NJ (this part) yesterday 830-5P. Trace with probably 1/2" melting as it fell with daytime temps near 30. Moisture froze on untreated surfaces at sundown. Snow redeveloped around 9P and as of 6A a densely packed small flake snow of 2.5" so far, easy to remove.

So to wrap up the thread: Nice snow and ice event east Carolinas/Va with northern fringe Wildwood NJ and also a period of 1-5" ocean effect snow showers for se MA. That was part one. The fritter part was attached below... two minor events the 23rd, 24th mostly N of I80 as attached.

Attached last evening and the past two day totals. Click for clarity, if interested.

fwiw... small flake light snow showers on going here in Wantage NJ right now as mPing picks them up. 714P/24

Here is the summary for the minor 0.2" CP snow and general amounts of t-1/2" for the subforum late yesterday-overnight. Click image for clarity of amounts. Looks like tonights measurable snow stays generally along and north of I84. E LI might luck out with mixed rain snow toward morning.

This will be the thread for tonights Part two, whatever it is... I80 northward. I do think it will happen..maybe a slippery icy mess on n LI (r/zr/s mix). Column is cold enough for snow tonight, with the surface temp & lowest 1000 feet governing results for LI.

Looks like it's coming per 00z/24 ensembles (EPS/GEFS/NAEFS) and the storm all have been looking for. Biggest is for e LI/Eastern New England but several inches possible down I95 to Raleigh with even dustings possible ATL/AVL. Depends on processes as usual. WPC overnight chances of 3"+ are still only 10%, except 30% BOS. But these probs do not reflect the 00z/24 ensembles. It's still possible ensembles will shrink seaward, but the trend is your friend with 00z/24 op EC/UK/GGEM on board. Bottom line: thread looks more like a hit than a miss.

Wantage NJ 0.4" final for this Sunday evening event.

for what it's worth, we augered 12" ice thickness on Culvers Lake in Sussex County Nj to ice fish. At least we still can do that for another week to 10 days.

My scientific expectation is that we have after the initial burst now near NYC at 715P, is that modeling may not be handling this very well. Lapse rates will steepen overnight as the short wave crosses the region around 06-09z...and the associated wind shift from sw to n (sfc convergence generating bands of snow) slips southeast across NYC to LI and may show as an inverted trough (light ne wind north of the convergence zone). I have to think at least another band of accumulative snow is in store for the I80 region (ne PA, NNJ,,se NYS,sw CT/LI). That could double the current new snow on the ground for nwNJ/ne Pa./se NYS, partly because of snow ratios. You can see the bands organizing on BGM/SCE radar. Also, what happens after 1 AM to sunrise is not my confident call but models indicate that somewhere across LI a pretty good band of snow showers should occur. I won't be staying up for all this but hope that this brings at least a little satisfaction to the NYC group of members.

Wantage NJ 0.3" snow continues lightly. 25/23

This subforum should see some light snow accumulations tonight with the 500MB cold trough passage accompanied by steepening low level moist lapse rates and the weak inverted trough back from the ocean storm that forces convergence-lift near I80-LI. Tonights snow should be a 0.1-1.5 inch affair. Frozen ground will permit untreated surfaces to become slippery in some areas tonight. Monday nights warm air advection snow (snow rain-freezing rain LI) behind the departing 500MB cold trough and well ahead of the late week 500MB trough should be of shorter duration and amounts probably less than whatever occurs tonight (less than 1" new), but still a contributor to possible slippery travel in some locations Monday night. While impacts minor-negligible, for those who want snow and receive it, this may have to suffice for a while. Timing for travel may be considerations, especially NYC-LI/CT Monday morning early commute if it's still snowing, ditto Tuesday predawn commute. Combined small event amounts via CoCoRaHs will be added here Tuesday and also as closure to the 21-24 thread.

The D7 from WPC i forgot to add 2 hours...

Am not threading 18z NAM for late 25th-26th at this time. One at time...Sun/Mon whatever it is.

17z/22 WPC D7... no 30% and the 12z ops also say, not likely right now for next weekend so not threading. Actually happy no 12z op has gone ballistic. Gives a chance of working nwwd. Have not viewed 12z/ensembles but will try and review everything tomorrow morning. I like the idea of only once/day close looks at D4+..allows the vaccinations to smooth out a bit. Hoping tomorrow mornings models hold onto a bit of snow late Sun or late Mon.

I'll take a penny right now. For us who have 3"+ on the ground, it was a beautiful crystalline subzero start to our Saturday. I too love this part of winter... my wife too. Cardinals at the feeders. Dog not wanting to go out- he knows.

I checked back--BOX had a WXA out for se MA at least back into their early Friday package. They knew...Ocean Effect. Some of the modeling had it, but imperfectly, as probably we all expect. Kudos BOX.

Of interest to me. Steepening lapse rates late Sunday with the CFP, and isobar hints of a weak inverted trough back from the Atlantic back into NJ, could bring small areas 1/2-1" snows to NJ/e PA. Also RGEM picking up on WAA small 1/4-2" snow acc down through the sub forum late on the 24th. Which is it, if either? I know we're all interested in next weekend... but the short term might provide a freshening bit of happiness to some parts of subforum landscape? It is cold and I'll take what we can get in this currently cold pattern.

So here's what has happened the past 24 hours ending around 8A snowfall wise. Three CoCoRaHs graphics. Click each for detail if interested. Massachusetts south shore (Ocean effect due to storm circulation) Wildwood area down to se DE on northern fringe of the synoptic snowfall. Jackpot for e NC snowfall.

Added RMOP: This can be helpful. Use the legend. Reds are high probability of being correct heights, blues indicate lots of uncertainty with respect to predictability. Added the 00z/22 GEFS trough for next weekend... big trough se USA but questionable ne USA heights (is it deeper, or splits east?) And the 360 hour which show confidence of the overall GEFS look at the pattern 16 day in advance. Use carefully but I don't see a big 2+ day torch yet...coming I'm sure since all of our long rangers are confident, but is it Feb week one (i dont think that is likely but may be a bad read on part--others chime the science on response to retrograde)? Week two: better chance of significant warming.

Part one of the 4 day thread: So we know it snowed 4 hours in Wildwood of extreme southern NJ overnight, and that the Boston area is picking up accumulative ocean effect snow showers, with one CoCoRaHs report of about 5" along the south shore. I'll add the CoCoRaHs mapped reports from this morning at about 10A for a summary on the part one failed for us ECWS. Part two seems to be gaining a little MINOR traction, from either scattered snow showers late Sunday (rain/wet snow LI), or a possible general light snow late Monday-Tuesday more likely for the I84 corridor, but possibly extending down to I80. Recommend following up here for this part two, if and as needed the next 2 days. Will adjust thread title slightly by 730A.