wdrag

I'll add 50 knotters if I get a chance overnight, otherwise a quick summary at 6A. Right now nationally on power.

As of 230PM. Negligible power outages in the northern USA. Should be more interesting tomorrow morning.

For what it's worth... Lords Valley in ne PA (CoCoRaHs), Poconos had 3/4" of snow in Pike County PA near exit 34 on I-84, before changing to sleet.

For what it's worth... Lords Valley in ne PA, Poconos had 3/4" of snow in Pike County PA near exit 34 on I84, before changing to sleet.

Southern Wantage NJ (8 s High Point NJ) had a mix of freezing rain, sleet, wet snow 11A-1P with a slushy slippery film on most surfaces. Newton NJ had icy spots in the County parking lot at 1PM tho the wet snow-rain mix had become all rain.

Southern Wantage NJ (8 s High Point NJ) had a mix of freezing rain, sleet, wet snow 11A-1P with a slushy slippery film on most surfaces. Newton NJ had icy spots in the County parking lot at 1PM tho the wet snow rain mix had become all rain.

Excellent! Thank you.

I continue interested in the fluxes with this storm, including front and back end snow here Sussex County/Poconos. Also with a a 970s low in the Great Lakes, hard to see how we don't see widespread 45 MPH gusts either Thu night or Friday. I know 850 winds are down from where'd I'd like and that the sounding is inverted or isothermal most of the time when 850 winds are more than 50kts, so this one may escape us without 65 MPH gusts (LI eastern New England) but I'm still looking. Regarding the apparently very warm shift middle of next week or beyond... I see it. Yet, ensembles still have hints of a minor snow over the interior from VA to BOS, 24 hr snow depth change centered around 00z/THU the 29th. I think the EPS still has favorable upper air with lagging 500MB trough to our west Tuesday evening... not so the GEFS/GEPS. So while it probably won't happen...it's not yet off the table til the EPS shifts the trough eastward faster. Yep, am grasping for straws... still this storm just ahead has my attention. FLASH FREEZE: I don't think this is defined in the Glossary of Meteorology. I'll try for an hourly 10 degree drop from above freezing to below freezing with precipitation ongoing through that hour. If someone is aware of flash freeze definition---please send us a note. Thanks

Not sure if anyone considered this... When surface pressure is below 1000MB at any location here, you can pretty much be assured that the sfc wind will gust at whatever the lowest model level wind is. I'll be looking at the the BL wind on the NAM FOUS61 tomorrow for a minimum gust at whatever it says. That is without turbulent-turnover transfer from above. So, if you have access to 1000mb winds today, I think you'll have an idea at minimum gusts Friday. After that. it's a matter of turbulent transfer whether it is from the low level lapse rate, or showery precip, or eddies of excessive wind aloft. I am looking for pockets damaging wind as early as 12z Friday, up to within 1 hour post CFP Fri afternoon. I am also favoring the stronger GFS on this. That could be my downfall. Glad I'm not flying Thu-Fri. Gone for the day.

EC doesn't have it (the Friday snow burst) yet, not clearly, but I trust the GFS. I think it's onto it. IF the GFS is wrong about the 975 redeveloping low in the Catskills Friday, then the snow burst is unlikely and a little less wind. I think the GFS is correct but maybe a couple MB too low. Meanwhile it seems the EC op is mostly onto the Great Lakes upper Ohio Valley blizzard. However, note the EC is getting colder and colder in the POCS newd Thursday. Check out the 06z/20.

So we are aware of wind, coastal flood threats with this storm in and near NYC and the 26th-28th period of snow or sleet potential that is seemingly coming back on board after a few days hiatus. The Thu-Fri storm may add some wintry interest: both front 9AM-3PM Thursday and back end 11A-5P Friday for Sussex County NJ to west of Hartford CT and of course the Poconos. T-1" snow-sleet front end, but back end looks much more potent to me, especially plunging temps and what appears to be a short burst of intense snowfall coating roads (0.2-1.5"). and NYC: I could see spotty slippery conditions developing sometime late in the afternoon with a short burst of snow (less than 1/2"). Modeling will help in the future confidence of any of this occurring. Will check back tonight or tomorrow.

D3 (Thu night) thunderstorm potential up here in the strong WAA pattern. Marginal risk is further south in e VA/NC.

I'm pretty sure GEFS and GEPS mean is 10 to 1 and converts sleet as well to 10 to 1. That can easily inflate numbers-mean. NWS please correct me if necessary on GEFS ensemble being 10 to 1. Thanks. Walt

I want to make sure this gets noticed: by all who have interest in GFS model snow fall in the United States. The model update on 11/30/22 I think is resulting in improved snowfall prediction. It certainly was a cyclically very good performer here in the NYC subforum coverage for 12/15-16. It's picking up on warm ground and elevations better. Attached are some notes from a recent presentation: I only snapped the primary conclusions. Note: Using 10 to 1 is not going to be a consistently good approach, especially warm thickness (1000-500MB 540DM or higher) snows and/or temps 32-34F. This presentation also references Tropical Tidbits Positive Snow Depth Change (SNOD in NCEP language).

Just in case no one knows: and this can be shared with all other forums. Below from an NCEP representative. The GFSv16.3 upgrade that occurred on 11/30 DID contain a correction to how snow depth is computed. We are confident that this is a very positive change to the model. I noticed this for the Dec 15 event... Positive snow depth change. Walt

Uncertainty this far in advance but by 11AM Tuesday, we'll know what the NAM and RDPS models say (72-84 hour). Let's see if global models lose this prior to tomorrow morning. I don't think they will. Globals since the EC switched inland cutter with the 12z/16 (last Friday) cycle have been onto this sort of wind/back end scenario for the Appalachians. Gone for the rest of the day.

Looks like everyone is reading the models. My primary concerns for membership. Poconos: A little ice or snow to start Thursday afternoon-evening, shouldn't last too long and probably minimal impact. A potentially far more dangerous situation is possible Friday when a 1-2 hour period of brief intense snowfall may occur as temperatures plummet through the 20s. If this occurs, it will be difficult to manage if traveling in this 2 hour window. Snowfall generally under an inch or 2, but if it occurs, would result in slippery travel everywhere. Timing and confidence of occurrence is below average but sometime between Noon and 6PM. Worthy of monitoring. Otherwise the main story is damaging wind that will make headlines from the Great Lakes and Ohio Valley, throughout the northeast USA. Looks like a period or two of scattered 55-65 MPH wind gusts is likely from VA northward to Canada. If you don't have a generator, be aware that if power goes out, you'll need to depend on other SAFE sources for heat and communication. This is because the coldest air of the season so far, should be in place by Saturday morning with subzero nightitme wind chills in the I-84 corridor northward and near zero wind chill in the cities from Atlanta to Boston. Due to the expected heavy rain: post cold frontal icing of any remaining runoff (road shoulders etc) is possible by Saturday morning.

RDPS 18z available on the Meteocentre web site. Ice far nw NC and far w VA at 84 hours.

Anyway: I hope we don't get shut out interior. Seems like we should get some ice or snow. I noticed the 12z/18 UKMET has a little slug of snow for the I84 corridor later Thursday. That could be ptype problem and not converting partly to ice? A decent band of FGEN shows on the Pivotal website at about 102-108 hours both 850 MB and 700MB and its subzero at those levels so we may have a chance small accumulative snow inland nw-n-ne of NYC?? That's me--- still holding onto hope. 18Z RDPS did not post anywhere as far as I know as of 435PM... definitely late.

Just a note here: I hear OUTLIER lingo on coming events, especially beyond a few days. Here is a case where the outliers (a distinct minority as Don noted) are correct. That's why stats are part of the solution (whiskers of possibilities) but can't be a sole determinant without some sort of thoughtful consideration.

I'm sorry, I don't really know. I think a secondary is going to occur along our Delmarva-NJ coast but not much factor, in comparison to the deepening of the vertically deep cyclonic circulation over the eastern Great Lakes.

I haven't given up on the two hazards (front and back end) but had to give it up for the coastal cities. Complex and the colder solutions are not yet kaput. Already 12z/18 NAM has positive snow depth into central VA. Could it be wrong??? yes, but I do think ice and or snow will develop in w NC and nw 1/2 VA at the very start. Can I hope for the 12Z/18 GFS to give me a little more to grasp onto?

Maybe we favor indices too much and not enough timing-track? I'm real glad we're not focusing on MJO in Dec. Long ways to go before we really know what is best fit for each storm scenario.

So far, I'M probably going to be WRONG about my scenarios for possible snow to the coastal cities Thu-Fri (other than flurries-ice pellets). 00z/18 operational models just too warm. Interior I-84 corridor still might have some wintry advisory hazards Thu afternoon-eve and Friday afternoon. Wind might be the greater concern (short period of 45-60 MPH gusts). Still looks like the coldest well mixed airmass of the season to the coast by Saturday morning lasting into the 26th. I see nighttime wind chill modeled to near zero in the coastal cities and subzero I84 corridor??? So a decent early winter storm. All the 00z/18 ensembles (EPS and CMC-GEPS have increased considerably) have a little more snow than I expect I84 corridor... and only advisory potential. While there can be changes near the snowfall gradient boundary, I think I'm now convinced that the coastal cities won't see much more than flurries or ice pellets.

Not going to post the graphics and may be meaningless??? but the 18z EC is 2C colder at 850MB IN NC at 90hrs than the prior 12z at 96 hrs. More cold air aloft to get rid of. I'd love to extrapolate but this can be a rabbit hole and useless. I do like that 12-18z EC trend, especially since it's 12z was implying a decent amount 850 MB se flow WAA Thursday. I won't see new model guidance til 6A..hopefully sleeping in. I