wdrag

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.

A quick note: Have seen some f the modeling for a big storm VA's/Delmarva se NJ/e LI. No topic-thread from me yet, until at least 4P today pending review of multiple 12z/23 ensembles and WPC outlook. This is the overnight outlook for the 28th into early 29th... we're on the fringe of the outlook, which looks reasonable to me in light of all the other guidance so far.

Good morning again, go for it! 12zNAM should be the start of some useful guidance on whether or not we can muster 1/4" or greater qpf and associated snow/ice/rain. I''ll revisit at 330PM. Third topic edits 626A/23: Delayed the start in the forum 3 more hours and that may not be enough due to the dry air in place, but sometimes the snow-sleet breaks out faster than modeled. I've had to admit a slower departure, especially because of the GFSv16 and EC. The following may be too high on amounts but it's just my opinion of the boiled down (in my mind) consensus of the 00z-06z/23 model suite. A colder week is now here with hazardous winter weather potential late Monday-late Thursday Late Monday the 25th-early Wed the 27th: Manageable. Still uncertainty on evolution. There is general model consenses for slower arrival and later departure, and less precip amounts. I am guarded about decreasing the wintry element amounts (low level pressure pattern, 500MB vort max track, GFSv16) but this update below may be an inch or 2 on the high side? Manageable delays sometime in this event due to plowable snow northwest of I95, except snow-ice I78 southward in NJ to Baltimore and snow/ice/rain NYC-LI southward along the NJ coast southeast of I95). The main event for I84 should Tuesday-Tuesday night. Expecting amounts to range from an uncertain 1-5" CT with the least in eastern Connecticut and a less than certain forecast there, to between 4- isolated 7" se NYS, ne PA and nw NJ. LI NYC/NJ coast 1" to possibly as much as 4" by the time all is said and done with the best chance for a POSSIBLE 4" NYC (possible, not probable). I expect plowing will be needed sometime for most of our area northwest of I95, except maybe east of the CT River. 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. This graphic attached was issued by WPC at noon yesterday, but I think still applies.

Note; The GFS para is running again, tho not n tidbits yet. Found on Pivatol. It is more robust than the GFS and many other models north and west of NYC. I'm not sure what to think of it.

Heres' the 3 day CoCoRAHS totals as reported for the daily tally.

My 3P/22 impressions: have looked at everything that's available via 12z/22 modeling except no GFSv16. In any case, I may be 6 hours too fast on the start and 1-2" too high on the high end of the ranges provided this morning. Advisory or low end warning most of forum except n of POU-DXR-HVN (drying out?). Shorter duration with primary impact Tuesday morning commute. snow ratios should 10 to 12 to 1 north of I80 tho no guarantee. Understand the concern about dry air eating up snow near I84 se NYS and especially CT/MA where greatest doubts. QPF is not impressive but NAEFS holding it's own...maybe south by 20 MI at most. I like the 500MB vort max translating east or east southeast across northern PA Tuesday. Unsure whether we can get a deep saturated layer up here between I80 and the NYS border? so the I80 axis should do well with at least WAA snow Mon night and east then sewd movin rh from southern NYS and northern PA midday Tuesday. My end time still close to 6P Tue but may lag a little per EC. Waiting this out a little longer. I think the NAM will become more helpful with 12z/23 cycle...still a little out of range and 84 hr NAM not known to me as the best of its output.

Good morning this Friday Jan 22: Think consensus is developing that most here will enjoy a significant plowable snow event late Monday-Tuesday. My take below based on 00z/22 ops and EPS/GEFS/NAEFS, and 06z GFS op. Travelers into the northeast USA Noon Monday- 6PM Tuesday the 25th-26th: While still some uncertainty, if you have travel plans into the I84-I80 corridors or I95 Baltimore to NYC-New Haven Monday Night-Tuesday morning, prepare for delays due to snow, except snow-ice I78 southward in NJ to Baltimore. Expecting amounts to range from ~1" or less I90 in Mass (could be zero if the storm stays south), to an uncertain 1-5" CT with the least in northeast Connecticut (Ashford) and a less than certain forecast there, to between 4-7" se NYS, and 5-9" ne PA, nw NJ. The high side 9" amount is no guarantee but it's in some of the modeling. Best chance of 9" in ne PA is along I80. LI/NYC my expectation this early is 1 to maybe as much as 6"??? with the best chance of 3"+ western LI/NYC. I expect plowing will be needed most of our area except maybe n CT/MA/ and the region along or just southeast of I95 BWI-NYC. Temps will be subfreezing throughout the event except if it starts Monday afternoon when it will take an hour or two to drop below freezing. Baltimore-Philly is in the ice-snow zone so amounts of each element will depend on duration but it will get slippery there for a time, possibly as early as Noon Monday. Finally: the end of this event should be Tuesday afternoon, but it's possible that it could linger into the wee predawn hours of Wednesday? Attached a NWS graphic ensemble 30+% chance of 3+" of snow Monday into early Tuesday. Blue is 50+%. This gives an idea of the focus only through 7AM Tuesday and it will snow beyond 7AM Tuesday- so this is conservative. Also the 00z/22 NAEFS qpf for the 24 hr period ending 00z/27 with .4" = to the 10MM line, and also the sfc temp for near 00z./27 which shows 0C along I95.

I agree on the above 2 by Bluewave et al 5th-Feb 2. Snowfall that I see on the 12zEPS is about 8" NYC and 10-12" central PA through Feb 5. fwiw and am ot intent on threading for a couple of days til we see more consensus for the 25th-26th, 12z/21 NAEFS for the 28th has a nice 12-18 hour snow event NJ-down to central VA. Pretty impressive on the NAEFS.

12z NAEFS continues to offer sleet/ice s of I80 for the 25th-26th, about .2 QPF to I84 and about .4 or so I195. I like that for starters. 12z/21 version slightly further n than the 00z and so despite the rather paltry GEFS, the GEPS compromised up and it sort of matches the 12z/21 EPS...the concern being how much snow can occur in n CT or does the modeled confluence slip south with time? Right now the EPS and GEFS have flip flopped from 3 days ago with the EPS much more favorable for a widespread snow-ice event in the forum. Therefore, I've no changes to prior topic threads, including rushing the first snow in NJ during the day Monday (not that it will be correct but i cant confidently way one way or the other)... a light to moderate advisory event with a possible small swath of low end warning. Best I can do. Taking down the Christmas tree... something I'm reluctant to do. Later,

You did real good... if ever lose my County job, i'd look at USPS PT. No matter the internal complaints... I know most of these jobs are highly desired, and all respected. Regards,