wdrag

are we still interested about stratwarm and potential ramifications mid and late Dec?

Ensembles shows some modest interest in snow/ice for the I84 corridor Thanks giving weekend and a period of advisory wind continues to be on the table. Am aware that many on here do not have access to Pivotal Weather ensembles. I'll post those when a thread is developed but I dont want to hype prior to. Hopefully you trust that 00z/20 CMCE, EPS, GEFS ensembles have something around the 29th... I used the more conservative 24 hr snow depth change mean.

Friday evening, I'll start the Dec thread due to already discussed Stratwarm and its impact as a pattern changer-plunger in North America. That way I can add the CPC week 3-4 outlook and any D8-14 hazards which I suspect will be developing in the east, beyond lake effect.

Back to the future: Ensemble qpf storm track more or less southern Plains to the northeast USA next 16 days. Ensembles have no snow prior to D10. but between D10-16 all ensembles try to bring snow accumulation down to the coasts (climo influence?). Nov 30th for now is the EPS next target day for a possible wind advisory. That's D11. Let see if I cant get D1 right... NAEFS has us chilling a bit in early Dec. Have a good day! Thanks for all the overnight reports.

Processes: Cannot circumvent checklists... pilots don't and they fly us successfully. I got a little lazy...circumvented processes. Saw the trend in HRRR/RAP/RRFSA prior to 14z/18 yesterday, accepted HRRR resulting in an F forecast. Global CMCE an EPS ensembles (GEFS, SREF and SPC HREF snowfall terrible) had the axis right which was near I80 but amounts below 2" on 10-1. That should have cautioned me on the 12z/18 verbatim HRRR post. ANDDDD when we're on the gradient edge of qpf, caution flag. I've grown confident in the ECAI but it failed miserably on the north fringe this morning and the EC OP through 00z/19 was lacking. 12z and 18Z/18 HRRR were very similar then I saw the 00z/19 HRRR drop back down to I80--wasnt sure it would hold there. It did. Bottom line: Follow processes ALWAYS inclusive of merging ensembles and being careful on the gradient edge. I sure hope to remember this lesson. Wantage Trace flurries and qpf... basically nil. Attached CoCoRaHs snowfall.

will very briefly explain my laziness via process and the F forecast around 945A.

I've seen an ice pellet report via MPING over sw Long Island at 320AM. Mixed rain/sleet NYC area with possibly a few wet flakes for the Bronx by the time 7AM rolls around.

Flurries have started in Wantage NJ... definitely a HRRR bust from yesterdays 12 and 18z modeling but lets see what the finals are. Sleet on parts of Long Island now.

I updated my 3PM comment with an apology explanation of ground truth knowledge aforehand of a product issuance.

I've seen some comments downplaying the HRRR. 18z vsn nearly identical to the 12z. I think we have to think confluence zone enhancement-band. I see BGM NWS just issued an inch higher terrain. I wont say what will happen but I dont even think our NWS offices will know at 3AM tomorrow when final day products are issued, since very few ground truth reports at 2-3A. The radar should be telling. at 346PM I apologize for being somewhat curt about this knowledge aforehand of a product issuance, but not too many observers of weather, especially rural areas are up at 230AM providing ground truth. ASOS snow isn't the best (Melting snow etc into liquid). Best I can do is make vsby relationships and bright band relationships (research on DBZ conversions-snowfall rate relationships was done a long time ago by a good forecaster at ALB). Maybe I'll be wrong but I doubt if the HRRR is going to miss by more than inch or at worst 2. It should be slippery as outlined in the mid morning post. Pretty good 5H Vort advection toward morning in EPA with decent 8H FGEN and lift in sw flow aloft. A warm frontal wave. It's over before you can say 9AM. Edited at 347PM with my apology explanation.

Well here's the thing... Globals overall have not held onto the structure of the oncoming short wave into confluence zone in NYS New England so have been depressed. 6z EC topped in favor of the 06-09z RRSFA, RAP, NAM3K and 12z HRRR. I sure hope the 12z/18 HRRR is not that far wrong... it could be too aggressive to the north but I expect a 2-4" stripe somewhere near I80 which would be a little south of the 12z HRRR axis. Uncertainty of course but we have to make decisions on what we do. So potentially embarrassing if it fails but this is what I updated locally. Updating I84 corridor 9AM. Plowing will probably be needed for at least the higher elevations tomorrow morning from northeast PA through nw NJ/se NYS into at least southern CT and possibly Hartford Ashford. Too much short term modeling that is at the leading edge of mesoscale modeling is upping amounts and predicting a decent 5 hour event that will require adjusted traveling times. Entire I84 region from the Poconos across nw NJ, se NYS into ag least the southern two thirds of CT 1AM-9AM Wednesday (tomorrow) morning. A 3-6 hour period of wet snow that likely accumulates 1-4"-especially grass. Valley roads 600 feet or below just wet because of temps just above freezing but accumulations on untreated pavements expected for the hills where the temp will drop to 30, especially 1000 feet or higher. The northern extent of the snow shield is a little uncertain but prepare for slower travel-delays in your early Wednesday morning travel. In my opinion there is an increasing chance of a 2 hour delay for high terrain schools I80 northward. Overall minor impact anticipated except during a period of heavier snow near dawn. The southern extent of snow somewhere between I80 and I78 and it probably will melt on most pavements south of I80. Monitor NWS forecasts and any advisory in their afternoon issuances. I suspect that their forecasts will become more formidable for our second accumulative snowfall of the season...and pavement covering too. I just dont think a 30-40% chc of precipitation covers it for tonight in nw NJ-NYC. Graphics are the NWS 7A snowfall forecast and the 12z HRRR which sort of mirrors the more conservative 06z EC. Click for clarity.

No thread subforum...posted thoughts in nw suburbs thread but I think Bronx NY will see a rain/wet snow mix 3A-9A Wednesday but no accumulation on pavement--- too warm I think.

Pocono region across nw NJ and se NYS into sw CT 1AM-9AM Wednesday (tomorrow) morning 11/19. A 2-5 hour period of wet snow that could accumulate 1/2-1.5"-especially grass. Valley roads 600 feet or below just wet because of temps just above freezing but accumulations on untreated pavements expected for the hills where the temp will drop to 30, especially 1000 feet or higher. The northern extent of the snow shield is a little uncertain but prepare to slow down a bit in your early Wednesday morning travel. There ?might? be a 2 hour delay for high terrain schools north of I80. Overall minor impact anticipated. The southern extent of snow somewhere between I80 and I78 and it probably will melt on most pavements south of I80.

12z/17 cycle in: No thread for the ECMWF first minor barely measurable snow NYC CP 09z/19 and the enthusiastic 11/30 I95 event which should soon be model abandoned- but offers some sort of hope? EC Ensembles are not enthusiastic for measurable snow NYC CP this month but the 12z cycle continues with a potentially wind advisory day sometime between 11/29-12/2. Right now ensembles are saying MAX G around 35 MPH then but for a 300+ hour ensemble, that is noticeably on the high side.

Looking ahead: Appended CPC week 3-4 from this past Friday... and the 11/16 ECMWF EPS from ecmwf.int charts seems to continue the trend to chilling northern USA in December and a storm track extending from the Oh Valley into our area. Could be too warm for snow in CP but I'll go with the standard first date of measurable in CP week two of Dec. That would mean maybe advisory snow-ice for the I84 corridor? LOOOOONG ways off so am only monitoring - not counting on much and skill beyond 10 days is limited, at best. 00z/17 global ensembles that we tend to use are not favorable for snowfall prior to Dec 2, excepting possibly the CMCE. In the meantime eduggs is onto it for overnight tomorrow night as an absorbed but still coherent short wave exits the mid Atlantic coast. No thread fr the subforum at this time nor expected---too limited on areal col erase and sfc/profile temps marginal. Regarding the next advisory wind event... not yet a certainty but a definite possibility between 11/29-12/2.