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I have misled on this one... Definitely need to see a northwest trend of 70 miles on the 00z/4 cycle for ne PA, nw corner CT to get anything more than 1-3" As everyone knows, i see the trend too... big development too late except central and eastern New England. I'll ride out the model sways... but I need to see a nw trend when I wake ups and look at the models tomorrow morning. I do think models are improving even from 10-30 years ago. What we have now are ensembles that help us gauge confidence and that helps many of us.

So... I'll be looking for NAM-EC agreement going forward, with GGEM further nw than previous 00z cycle. IF not, then I favored too far northwest-erroneously.

agreed... still model tracking uncertainty. Example 06z RGEM a little further se than prior version. My guess is where more certainty with WPC collaboration, some sort of issuance will occur late today... again consensus-collaboration. I tend to push it... NWS more conservative (except NHC- I like how they go about long lead time-my view only).

90Left of the 850 LOW...that's a start on max axis (provided cold enough)... nothing has changed since that was uncovered decades ago.

Retired... have a little FB group for hazardous winter wx and the NYC forum. Still have to be careful. My recent sense on modeling... when NAM and EC op are in agreement, that's a good sign for their combined impact. AND.. I want to the have the GGEM sort of close.

Good Thursday morning everyone, (Dec 3), Think it's soon going to be watch time for a HIGH Impact Multiple hazard event in our NYC forum. Topic initial discussion is a baseline start but I have to trend a little stronger confidence on probably more substantial impacts than initially framed. My main question now...track of the surface lows and a little uncertainty on the speed. The 00z/3 cycle has trended northwest and GEFS is coming into much closer alignment with the EPS regarding the developing closed low 850MB-500MB. Power and Snow: It seems to me a significant amount of power outages are in the offing for portions of the I84 corridor, especially high terrain, Saturday from a combination of wet snow exceeding 4" and north or northwest wind gusts of 35-45MPH. Meanwhile, for LI-southern CT, and possibly coastal NJ power outages similar or a bit more than 11/30, would be from initially east-northeast wind gusts of 45-55 mph with a back side burst late Saturday. Wind gusts "may" reach ~65 MPH on eastern LI. That will be my max. Max snowfall in our area: northwest fringe along or north of I84 certainly can exceed half a foot-don't want to get too confident on this yet... we still have tracking disagreement. Some models favor n CT/interior MA and others, I think more accurately, Poconos northeastward to the Litchfield Hills of nw CT- Berkshires. NYC: Snow accumulations may occur at the tail end Saturday night or early Sunday to within 10 miles of NYC, and even NYC could see a flurry or period of wet snow. Flooding: My guess based on MMEFS and the likelihood of 1.5-3" of qpf over the vulnerable NJ basins along and northwest of I95, that flooding will occur on all rivers and streams that occurred on 11/30-12/1 and add a few more rivers. Thunder could occur in our area during rapid intensification Saturday. Did we miss anything? 507A/3

And finally some time to look back... CLE area 10-20" ending predawn this morning.

Caught my attention. Whilst the JMA is so flat and fast, we'd get 1/4" rain at LGA. We've been blessed with excellent lead time signals in the modeling (5+days). This one more like previous winters. By the way, posting in a minute...CLE area had 10-20 ending early this morning.

My last of the evening... I saw the 18z/2 EC... well, if this occurs, it's HIGH impact for our area...probably more than 11/30. Until I see the GGEM/RGEM climb back aboard, I'm going to hesitate and temper. I maintain, no big synoptic scale qpf if the GGEM is not on board. I just don't see the GGEM fail. If anyone else sees it different, let me know. When the GGEM is dry, think twice. Anyway, time for a northward trend in the 00z/3 cycle. With anomalously warm SST along the mid-Atlantic coast, if the short wave does go negative and close off, it would be explosive development and that development has been signaled by the EC/NAM the last several cycles. Exactly where this occurs? Lot's of potential ahead... let's see how much is yielded.

Keep discussiing... I've been off line since 630A (floor install). Have checked some ensembles etc from the 12z cycle and generally a southeastward trend... however, there is time to come back a little. I probably wont comment much more til Thursday morning 630A. I see the 18z NAM looks a little further north and slower on qpf. Think it best to wait this out a bit. For now, I don 't see any worse than what was written in the topic...SST above normal mid Atlantic waters.

Good Wednesday morning, I've no changes to this topic. EC-EPS are far different than the GFS-GEFS. NAEFS leans EPS and that is without the ECMWF members. That tells me the EC needs to weighted heavier than all the models. I still don't want to believe it's that strong when it comse through our area but potent for heavy wet snow it is, for northern PA-central and eastern NYS (except extreme se), and northwestern New England. So, everything stated in the topic is reasonable, I think. Will rereview late today. WPC has some pretty large rainfall for our area (widespread 1.5"-2"). Some of modeling is continuing or adding potential for strong easterly flow ahead of low. Needs to be monitored for the midday Saturday night tide, especially if surface pressure dips below 990MB s of ISP.

From what I can sense through 00z/2 ensembling... it looks like there is going to be a cold intrusion next week into the northern tier with the next large scale storm toward the 14th (after this weekends). After that... no super warming immediately modeled prior to the 16th. However, it is LaNina with AGW. I might be seeing some sort of blocking trying to get going up by Greenland. Unsure if that is going to occur.

Overall, have nothing more to add to this topic. Past two topics give a feel for useful 5+ day advance predictability as the amalgam of model blending is permitting preparations for mitigating adverse weather impacts. Not always but overall, modeling in some patterns is becoming quite good 5-10 days in advance. Just have to use all the tools and ballpark an idea of the future, carefully sharing with the public in a manner that can be reliably helpful. 2/522A

How about this... OH...ne corner, now up 82,000 meters without power... probably 200,000 people. Still snowing pretty good there.

This topic for Friday-Sunday dual event is posted with much lower issuing confidence than the topics of 11/11-15, and 11/30-12/01. There may be several verifiable flood (not flash flood) warnings for rivers-small stream in northern NJ-northwest of I95 by Sunday morning from a widespread 1-2" rainfall, isolated 3" possible. There is a small chance for 45+ MPH gusts. It appears the best chance of verifiable hazards will be along the I84 higher terrain where ice or snow can occur. The ice or snow amounts 3-4 days in the future cannot be counted on to be more than 1 tenth inch glaze or more than 3" of snow, though the option exists for heavier snowfall north of I84. Lead precipitation Friday afternoon and night is associated with a reinforcing cold front. Rain NYC. However the I84 corridor may see some wet snow Friday night? mPING. Saturday: Chilly rain most of the NYC forum, heavy at times with 1-2" general, isolated 3". I84-best chance that there could be some ice Saturday before cooling thicknesses and the rapidly developing low change precipitation to some snow before it ends Saturday night or Sunday morning. mPING may be quite helpful. Winds: Depends how fast the storm develops. If a 998MB low is south of Islip Saturday-then brief northeasterly gusts 40-50 MPH Saturday would be possible on LI and the NJ coast, otherwise I think there may be a better chance of northwest wind gusts 45-50 MPH Saturday night or Sunday morning as the storm moves rapidly past Boston. After further review, I don't think tidal flooding will be a significant threat Saturday. Starter graphics: 6 hr FFG..shows the vulnerable areas. Once yesterdays wave off rising river waters passes Wednesday night, I'll add some small stream guidance-if it applies. Added the 12z/1 GEFS prob of 1". Yellow is up around 75-80% chance. The 12z/1 EPS also has 1-1.5" as does the 12z/1 NAEFS. Final starter graphic is a 52 member NAEFS blend of where the sfc low will be and it's intensity Saturday evening. You'll note the yellow color northeast of the center... that implies greater variability of the pressures there..and could mean that the surface low will be further northeast by Saturday evening. Good luck with this... I hope this topic will produce some verifiable NWS hazards. 521P/1

I'll post a new topic for Friday-Sunday dual event ~5P. Confidence is much much lower than the topics of 11/11-15, and 11/30-12/01. Ensembles are not as favorable for verifiable flood warning, wind advisory or greater, with maybe theist v reification possibilities - the I84 corridor having winter hazards (some ice or snow). Basically, if the 12z/1 EC op didn't do what it did today, I would have held off til tomorrow or beyond, to be more sure.

Hi! I want to think things through before probably posting a topic at 5PM, including check of 12z/1 ENS (GEFS/EPS/NAEFS) upper air patterns and the 850 wind flow. Modeling is favoring another storm of power outage potential (wind, perhaps 4+" wet snow extreme nw fringe of our forum with backside wind gusts 40+ MPH) and travel issues for late Friday into Sunday. Unsure how it evolves... NYC probably all rain til flurries at the end...I84 more complex. EC wind gusts 50+ now both front and back side for portions of our forum so power outages may not be much worse than yesterday but still a consideration. If the storm runs slower and max easterly inflow is midday Saturday, then a tidal flooding problem would develop. Thanks for your patience.. Walt 156P.

fwiw: northern and eastern OH still 60,000 meters without power, equivalent to about 150,000 people..most of it near and east of CLE where 6-12" of snow has fallen and they continuegetting hit pretty hard with another 6+ on the way some of that area. Wont surprise ant near 20" east of CLE high terrain. Bummer for power out and 30F air temp.

Yes, though I'm not quite sure if this intensifying trough will close fast enough (PA) before reaching our longitude (LI). BUT.... the backside wnw wind cold air advection(CAA) might provide at least 40-45 kt (wind advisory) gusts... possibly higher, depending on cloud cover and lapse rate... It's usually bit easier with 50-55kt 850MB winds to transfer in CAA during the day, whereas to have yesterdays southerly WAA wind, you tend to need 70+ knots at 850MB.

It's a member but I think its far too slo.

I corrected my prior RMOP post with adding the proper previous cycle forecast for 00z/7 as the 3rd frame. Now you can see the difference. Also put it in here... Finally...here is the 06z/1 500 MB GEFS. Pretty confident membership on something sizable PA or NYS (upper low) for 00z/7. Which is it? north of us...probably, but I think there will be a triple point low off NJ.

Hello again... as of around 9AM... here are some numbers. Here's a snowfall map for Ohio this morning via CoCoRAHS, and power outages now up to 55,000 meters as wet snow accumulates ne OHIO above 4". And then rainfall via CoCoRAHS and NYS mesonet, general 1-3" with a number of 3-3.5" in nw NJ and interior se NYS. This will have been a fairly large impact storm for the coastal ne USA, and northern Ohio.

Of interest to me and for I84 northward winter weather interests. Note the side by side forecast for 00z/ 7 RMOP confidence (for Sunday evening). Two things... heights are 60 meters or more deeper on the 1/00 run than that of 00z/30. Two: vort max passage s of LI and likely triple point low s of LI... and position of the trough. This increases my confidence on a sizable event and winter weather down very close to I84. added the 3rd frame...the side by side of the previous 11/30 cycle for the second frame, same time. Now you can see.

Good Tuesday morning everyone, Dec 1. You may be in the mix for some ice or snow this weekend... marginal chance, but I think some ice or snow is possible. Please see details on the December topic 544A post. I'll shift everything here in the future, IF NYC is completely out of tail end trace snow and we are still in the mix. Probably won't happen til Thursdays posts.

Good morning everyone, Tuesday Dec 1! No topic yet... but the 5th-6th -possibly into early 7th, looks like a rain storm for most of the forum but may have a little ice for the nw edge of the forum I84 region, ending as an inch or two of snow, especially later Sunday the 6th. Overall a short wave dropping south in the Rockies this morning closes off and marches east this week, opening up a little over the Midwest then closing as it goes by LI Sunday with a surface low modeled-ensembled through PA-LI, intensifying as it moves to the northern New England coast late Sunday or Monday morning. NAEFS 52 member 500 MB heights are modeled to deepen 120 meters/24 hr period between the 5th-7th with the 500 MB vort max of the deepening 500MB system crossing NJ Sunday. The 00z/1 EPS does not have this, leaving too much of the lead short wave behind in the sw USA. It could be right but I don't think so. I expect the future EPS to gravitate to the GEFS/NAEFS solution at 500 MB. New 00z/1 RMOP not yet available to do a reality check. So, despite the 06z/1 GFS OP run, I think this deserves some monitoring - just can't topic it yet due to less severity, wind and storm totals wise, than what occurred yesterday-Nov30. Snowfall, mainly nw edge of the forum---IF that far south. I am looking at it carefully. As many will say, probably not much if anything wintry up there near I84 but I'm not so sure---certainly can see a period of hazardous minor ice or snow. 544A/1