wdrag

I can live with snowfall #'s presented here except it look s a little low CT. I'd like more snow but if sleet/freezing rain/rain depending on location get involved, then the big trim as posted herein. From what I can tell this has slippery on all untreated surfaces almost from the start on Tuesday and a possible refreeze Tue night along the margins where it rises to 33-34F later day or eve. I think the darker yellow ice #'s might be a touch high but jury out. Bottom line...some sleet or freeIng rain appears to be coming across NJ, LI (ice LI temp dependent.) Back in the morning.

Because sleet is treated as snow acc at 10 to 1 and it's usually much less, maybe 2.5 or 3 to 1? Bottom line, inflated. Best to start with positive snow depth change and think it out form there. Or if you have the model data... monitor the EC etc snow depth change and use that as a bottom #.

Minor for snow, and an advisory would possibly not have been issued for ONLY the snow amounts posted, but we're dealing with frozen ground, snow and maybe sleet/freezing rain mix, and maybe e just a little more qpf than what is modeled if the inverted trough proves real. Also, this is a at least a climo advisory event. Might need to deice aircraft. I don't think is melt on contact unless treated surface. Jury may be out on final snow. I'll post the CoCoRAHS finals either Wed or Thu. Probably 32F or below through the entire event nw of I95 and maybe even NYC/LI. NAM BL temps 2C at midnight tomorrow night might be okay at the top of the BL but if the wind is turning north...then I suspect colder CT airmass seeps down across the sound. So yes, minor- however, hazardous untreated.

Thanks... I think NYC is in it now. Impressive collection of EPS lows s of LI 00z/Wed. Nice inflow potential.

WPC Dayshift outlook for Feb 1: Let's stay w general ensembles and hope for the best.

Hi!. The following is a start for the advisory. I think it will eventually need expansion to all of LI. At 6P, I'll add the new regional snowfall forecast. mPing and icy and or/snow covered pavements here we come for a manageable minor advisory event, that still has 1+" snow possibilities for LI, especially if we get the backwash (sewd moving) after 7AM Wednesday, associated with the developing low s of LI. Think we may see some surprises on qpf over 1/4" on LI. TBD.

Understand completely: May be the 12 and 18z 3K NAM can lock in on our qpf and types? That and RGEM HRDPS would be worthy of following. EC already steady now on I80 north.

637AM Sunday: : headline updated to Major near blizzard and added power outages. Major near blizzard Nor'easter coming. I would not plan on driving anywhere on Monday in northern NJ, ne PA, se NYS and ditto CT Monday afternoon-night, MA Monday night. NYC my guess is a foot, possibly more before mixed Monday night. Otherwise, amounts between 1-2 feet from I78 northward with lesser 8-18 inches CT and MA where rain/sleet invades later Monday night. Isolated 30" possible nw NJ, or ne PA into the Catskills by the time this storm ends early Wednesday.. Drifts 3-4 feet. Power outages possible Monday afternoon and night from northern NJ northeastward to CT and Boston from a combination of heavy wetter (heart attack for the hear tcondition vulnerable) snow and northeast wind gusts of 40-55 MPH. Snow starts central NJ around 3 PM, northern NJ-ne PA 6-10P, CT around dawn Monday. Worst of the storm NJ/PA sunrise Monday-midnight Monday night, CT Monday afternoon-night. Coastal flooding may be major near the midnight Monday high tide cycle? Follow NWS. ---- 615AM Saturday: Imperfect probably messy big snowstorm is coming, imperfect in that modeling the past 24 hours is drifting north and suggesting a dry slot late Monday will allow enough warming for sleet (rain LI) to I80 including all of I95 Monday night so that the stratiform burst of 1-2"/hr Heavy snow during Monday, especially afternoon, becomes bands of snow in the interior late Monday night-Tuesday, some areas probably recovering Tuesday with several hours of no precip. So, my own single forecaster point of failure but use of ensembles could be too pessimistic about the sleet/rain intrusion. For NYC... I'll start with 6" with possibly as much 1/2" late 31. Hope that its mostly snow after 00z/2 but even if, snow ratios may be down to 7 or 8 to 1?? I dont' want to cap NYC since am uncertain about dry slot. Sleet/rain/freezing rain may be getting involved Philly to Toms River during Monday morning. There may be a period of near blizzard conditions on LI centered Monday afternoon? BUT, I don't want to call it a blizzard for fear of easily missing criteria. The point of this paragraph, is that I think Monday, especially afternoon should be the worst period of travel and if models continue this, in future cycles through Sunday morning, then I think it would be a recommended no travel for that 6-12 hour period to limit accidents and allow plows to maintain passable-less slippery conditions for first responders. Snow may be wet on LI/Monmouth-northern Ocean Counties in NJ if 6" at 32-33F, we would have power outages... still too early to be sure. CT I84... continue to notice some multimodeled lesser snowfall there, so while I think a big snow there, cautioning myself. Coastal flooding: see NWS statements/flood watches already posted and no change from yesterday with the late Monday evening high tide cycle most favored for flooding (within 2 hours either side of the time of high tide) Graphics are the 00z/30 EPS as a base amount, the 00z/30 EC IR prediction for 06z/Tue showing the dry slot penetration, and the NWS 09z/30 prob for 6" or more of snow by 12z Tues. That's the reasoning basis for this update.

Other than band or two of flurries in the eastern part of our forum Thursday, it looks like this will be too little too late.

Pretty decent sub20F for NYC looks like Fri-Sat mornings in NYC... and so one shot of the coldest looks pretty certain now?

Good there...not quite so safe down here near Culvers Lake. Enjoy. This period between 1/23-2/2 is the way its supposed to be here in winter, in our entire forum. Climo.

Will start an OBS thread for this event (or non in the eyes of many here in NYC, but climo it is)... probably starting this obs-nowcast thread at 7P tonight.

635 AM Monday Jan 25: Added two graphics for the coming extensive minor snow-ice-snow event with main impacts LI-NYC-I95 corridor northwestward to the Adirondacks and New England Could be sneaky icy along the coast. mPING will be helpful. NWS snowfall forecast map added from 5AM this morning (NYC-LI generally less than 1") and also the probabilistic chance of .01 freezing rain. Mostly a Tuesday-Tuesday night snow-sleet event changing to freezing/rain-rain during the afternoon I80 southward possibly going back to snow or flurries Tuesday night or Wednesday morning. Advisories already out near DC. Expect it will be briefly slippery everywhere in our forum for a time Tuesday, and probably Tuesday night-Wednesday morning LI-NYC-I80 northward, especially interior. Expect plowing small amount amounts of snow entire I84 corridor with road treatments necessary most of the remaining portion of our forum except possibly just southeast of the I95 corridor. Weak boundary layer winds with a north-northeast drift will probably assist on keeping temps on the colder side of the available guidance. Storm impact of all snow will be larger I84 northward and inclusive of I90 to Boston with decent amounts. This keeps this brief and we'll all be monitoring the models. Hopefully there are no slips/falls/accidents Tuesday-Tuesday night on all untreated surfaces.

Will reassess tomorrow morning. I'm not changing from this morning. Very difficult for me to see avoiding an advisory event for much of the forum except parts of LI and the portions se of I95. The ice mix would be the key component s of I80. Regarding the rest of the area... I think this entire shortwave process is delayed 18-24 hours from when this topic was initiated, for ejection delay out of the Rockies and it's in my opinion stronger. So the topic start end time will probably end up wrong by 18-24 hours too soon, but it looks cold to me with convergence in the isobars, and possible trowel back from the ocean into ne PA on Wednesday and so periods of precip, generally freezing or frozen inland through Wednesday. NYC I think will see measurable snow. Maybe the 00z/25 guidance will sway me down but I don't like the GGEM and RGEM b being pretty decent n of I80. The only thing I'd change on my expectations is to spread decent snowfall across all of CT and I90 and looks to me like 2+ eastern CT I90 for starters. Back in the morning to rereview. Thanks for all the feedback on this topic.

It's not over, but not looking good for much if any snow here Thursday. GEPS and EPS led the way on being down for this event. Again not over, but nothing much enticing, Which means, enjoy whatever we get Tuesday-Wednesday.

Take whatever we can get. SPC SREF snow plumes NYC event for Tuesday-early Wed. Use as you wish... probably good to stay off the high side of the plumes for now and slice an inch off the mean... tho I definitely think 2" for NYC is a good possibility for this pattern.

Also noticed the UK ditto. has NYC down to near 15 on Friday morning and 13 Saturday morning. That is probably too cold but with northerly flow behind the departing late developing nor'easter and with a little luck a 1" snow depth, we could do it.

Do we finally see our first sub 20F in NYC CP , this season, Saturday morning the 30th. GFS TSections pretty cold.

550AM sunday: This is mostly a Tuesday-Tuesday night event. Periods of mostly light snow, at times changing to sleet, freezing rain (rain where above 32F along the coasts) or freezing drizzle up to I80, NYC, LI. Snow amounts trimmed a bit and I sure hope NYC can muster 1/2-3" depending on precip type and intensity for this event. I pushed the start time back to 7P Monday but it could be delayed NYC-LI-CT til as late as 9AM Tuesday. Also took MODERATE event out of the headline. Banding signature suggests snow should break out across PA/NJ between 7P and midnight Monday. The primary event is the 26th, ending sometime Wednesday morning. While amounts are light, suspect there will could be a period or two of 3/4mi light snow - bordering 1/2S for an hour or two, from northern NJ into ne PA/se NYS and western CT. 06z/24 NAM banding signature and also seen in the 06z/24 GFSv16 qpf, that the heaviest snow may occur early Wednesday near NYC. This may be associated with a trowel/inverted trough/ departing shortwave with the weak seaward moving low pressure. Something to monitor but not get hopes overly high. So, manageable delays sometime during this event due to plowable snow northwest of I95, except snow-ice I80 southward in NJ to Baltimore and snow/ice/rain NYC-LI southward along the NJ coast southeast of I95. Amount expectations lowered to range from an uncertain 1-4" CT with the least in eastern Connecticut and a less than certain forecast there, to between 3-5" se NYS, ne PA and 2-4" nw NJ north of I80. Temps will generally be subfreezing throughout the event except NYC/LI/NJ coast which are in the margins of ice-snow at the start, changing to periods of rain then ending as snow, so amounts of each element will depend on duration but it will probable get slippery there on untreated surfaces for a time as well-especially if and when precipitation occurs during the nighttime hours. Check others herein and other resources for other opinions. Added some graphics which are probabilistic. use read the graphic and probability legend. I did not add the NWS regional snowfall forecast because it ends at 7P Tuesday.

Good Sunday morning everyone, Jan 24. I dropped the rain out of this Thursday 28th topic. Otherwise I leave with two WPC graphics from their overnight shift (chance of 3+" of snow --see legend-chance is in the 10-29% category for the southeast part of our NYC forum, and their QPF forecast). I see this as a grazer, at worst ,between LI-I80 and I195 (TTN east). There could be a period of snow or flurries up to I80/LI Thursday morning midday- but otherwise so far, guidance suggests mostly a miss to our southeast- development just a little too late. However, do monitor future guidance. There still is a chance of a track that is a little closer.

I think so. It really is nice, despite the degneral lack of snow. If we had more days like this we could skate here in nw NJ.

Low pressure in the Virginia's late Wednesday will get picked up by an intensifying short wave moving east across the Mid Atlantic states Thursday and become a pretty good sized nor'easter as it departs the mid Atlantic coast Thursday afternoon. Does development occur fast enough to bring significant wind driven snow to a part of the NYC forum (rain or snow LI/NJ coast?)? 12z/23 GEFS is fairly robust on qpf, but further south than it's 00z/23 version, while 12z/23 EPS and GEPS are indicating too little too late. One small caveat: the low levels should remain fairly moist after the Tuesday - Tuesday night ( 26th) event (whatever it is) and there may be some advance snow or snow grains/freezing drizzle/drizzle late Wednesday or Wednesday night, in part related to leftover moisture and some sfc convergence. That too is an unknown. Added the WPC day shift forecast qpf and chance of 3+" of snow (darker green). Will update Monday the 25th, when some of the nor'easter threat to our area has resolved itself. Also added the NAEFS qpf... seems a little high near and north of I80 but it could happen. Also added the 12z/23 GEFS 500MB spaghetti for 12z/Thursday.

No confidence on downgrading changes to thread thinking on the coming event, despite a number of models too dry to support. I could be wrong but what I see is a good cold BL to overrun...(850MB initial sw flow lift Monday night becoming light s-se for a time Tuesday) I also see the 'potential' for some nearly stationary subtle banding somewhere between I80 north to maybe as far I90 Tuesday-Tuesday night, along and north of the mid level vort stretching eastward. There is very small potential that this will become an inverted trough northwestward by early Wednesday to near KMPO or KABE, as the surface low redevelops eastward out to sea. Then its dendrite growth etc. Too far out for me to be confident in a marginal situation but frozen ground (even if above freezing Monday) and the good chance that ice will be mixed in almost up to I80 argues for a probable manageable advisory situation. Even if 'isolated' all snow 6+ occurs north of I80 in far nw NJ/ne PA/se NYS, since it's stretched out over 24+ hours, criteria won't be met for a warning event. No matter... snow and ice is coming with I think the deepest accumulation north of I80 but debatable and so I will maintain close to the 6a update and reevaluate tomorrow morning. By then we should know if the NAM is going to start developing qpf of .3 to 5" over a 36 hour period I80 north, and if the GEPS is going to lose it's 1/2". Added two ensemble plumes for KLGA. Both are a little interesting. For now, I'd discard everything above the mean,.and think an inch less then the mean presented. Later, Walt

Will begin a topic for Thursday - the 28th (r bleed Wednesday afternoon into Thursday night) for a rapidly deepening storm off the mid Atlantic coast but; will this miss the forum, at least the region along and north of I80? My gut tells me on too late for much up here n of i195 but bears watching for the mid level deformation zone well north -northwest of the storm center. I know this is a topic that needs concentrated forum discussion energy separate from the coming minor to yes, still moderate potential event for late 12/25-early 12/27. Drafted by 4P and very loosely. I think we need to pin our hopes for plowable snow I80 north, on the 26th, but I could be VERY wrong about the 28th. Therefore, keeping it loosely developed. Let me add; I know lots of folks here don't like the GGEM/GEPS, so thats our hope for the 28th (GEPS very very modest), and fairly warm up to I195. .

I added (not to this graphic) but the snow from 7A yesterday to 7A today, total 5.2" at MPO this week. Fabulous day to walk in real cold and wind up here in nw NJ at midday. Temp in the mid 20s and wind chill who knows, w a few flurries.