wdrag

No thread initiation by myself, since confidence on anything more than scattered G 43KT for 3/26, 29, 4/1-2 is below average. It will be windy at times. Go for it if you're confident, especially if systems amp up to sfc G50-55 kt potential, in our subforum. No leafout yet, probably favors a little lower chance of wind damage problems but wet ground may compensate for easier uproots. Still think we need to see more wind in the surface based instability part of the sounding. Events previously the past 12 months had about 75-90kt at 850MB, and 10m winds around 40kt along the LI coasts, with EC modeled sfc G all showing 50kt+.

On the GFSv16 upgrade: Unsure if this is anywhere in American Weather. Below from Phys.org US weather model upgraded to better forecast extreme events by Seth Borenstein In this Monday, March 15, 2021 file photo, snow covers vehicles parked along Second Avenue after a powerful late winter storm dumped more than 2 feet of snow in Denver. The storm shut down major roadways, canceled school and closed the state legislature. On Monday, March 22, 2021, the National Weather Service upgraded its forecast model, with an eye on predicting extreme weather events better and faster. (AP Photo/David Zalubowski) The National Weather Service has turbocharged its lagging forecast model to better predict extreme weather events such as hurricanes, blizzards and downpours, as well as day-to-day weather. By including much higher layers of the atmosphere, increased factoring of ocean waves and other improvements, the weather service's update to its Global Forecast System is trying to catch up with a European weather model that many experts consider superior. Tests for the past two years show the upgrade, which kicked in Monday, forecast heavy rains and snowfall 15% better five days out and improved hurricane and tropical storm tracks by more than 10%, better pinpointing storm formation five to seven days in advance. Forecasters say this new model does not predict more rain and snow than actually arrives, which its predecessor had a tendency to do. The new model was significantly better at forecasting the massive Colorado snowstorm earlier this month, getting the storm arrival time and snow amounts far more accurately than the older version, said Vijay Tallapragada, chief of modeling at the agency's Environmental Modeling Center. Internal studies also showed the new model was generally more accurate earlier on downpours in the Southeast in February 2020, Hurricane Dorian in 2019 and Hurricane Michael in 2018. "This is for the general day-to-day forecasting and for the extreme events, and you've got to get both right," said National Weather Service Director Louis Uccellini. One main improvement is that the new model captures the atmosphere up to 50 miles high (80 kilometers)—far higher than the old one and has higher resolution at different levels, weather service officials said. This way it better characterizes the jet stream, which transports storms, they said. Over the past 31 days, there was a stretch of eight straight days when this new version beat the highly-touted European forecast model, but in general over the period the European version was still better, Uccellini said. "Extreme weather events are becoming stronger and happening more often in a changing climate," said Bernadette Woods Placky, chief meteorologist at Climate Central's Climate Matters program, who wasn't part of the upgrade. "Weather forecasting improvements that increase accuracy and warning time will give people more time to prepare and will save lives."

Am working now, 2-3 days/week. Fewer posts. I will not be on top of isolated svr events. Something like what might occur (broad synoptic scale) Friday, I'll try to thread once it looks a little more certain. However, if others are more confident...go for it. Thanks. Was a good winter. If any modeling surprise, it wasn't the advance notice, it was the total failure of March 19 MA southward. I suppose someone could say that ensemble chance of 1" were only 70-75% in MA to the far nw side of our forum, meaning there was almost a 30% of a non 1" event (verified), it still is very seldom that events are total busts (no accumulation). So the surprise on the large scale events are very very few, and this one was on the downside (for me).

Thanks... ad just saw this on-line. Monday: Effective March 22, 2021 . Updated to reflect delay in implementation date to Monday, March 22 due to Critical Weather Day. Effective on or about March 22, 2021, beginning with the 1200 Coordinated Universal Time (UTC) cycle of the Global Forecast

What's the scoop on GFSv16 implementation. Doesn't seem like it happened as scheduled on the 17th. Did I miss a message? Thank you, Walt

EC op almost 90 KT at 850 Fri AM, GFS ~80, GGEM ~70; All ensembles considerably less. Worthy of monitoring for a while on a possible SVR wind event FRI AM or midday?

Saw the note on the cutter: If EC right, it's modeling decent wind on Friday the 26th. 40-50kt. Questions about including lapse rates, and intensity track. Impact less in early spring w no leaves.

Can't disagree on model performance horrible. Even where ensembles had 1"+ snow n of I84... just wretched. Wont post CoCoRaHs: not worth it. believe it or not, spotty 1/2" se NYS, nw of the forum, and would you also believe MVY and ACK had .1 to .3" as of the the reporting time this morning. Grade on this thread: nice LT but results were a non event throughout. Poor.

Other than e LI little hope for anything on the grass. NYC had a T of snow between 2-330A but basically no winter weather drama. Typically used modeling wasn't good. Even the region up n of I84 was a bust, where ensembles had much better chances. Will post whatever CoCoRAHS snow reports, in graphic format, toward 7P as a wrap. Whatever late winter chance we had for snow in NYC, this may have been it this week.

Converted to OBS-NOWCAST. No time to attempt modeling edge. A lot of this will happen when our members are sleeping midnight-5AM but my guess is there should be slippery spots in and near NYC predawn Friday with strong CAA and snow showers ending between 5A and 8A. NYC should trace and maybe get lucky with a few tenths between 2A-6A, with apparently now greater odds for a few tenths of an inch of snow e LI, and just s of I78. I don't really know what will happen. Up here Wantage way, far nw NJ, hope to see a dusting but we might miss? My this be last decent chance of measurable snow for the 20-21 winter in NYC?

Will convert this thread to OBS-NOWcast this evening, Not much there for i80 south including LI. Best chance for accumulation snow appears to be I84 northward. NAM yesterday was among the modes taking the lead on less snow risk NJ/LI... we'll see what happens. NWS ensemble chance of 1"+ and the NWS 5AM/18 forecast of snowfall for the northeast. Please use the legend for your area. No updates from myself til this eve. 604A/18

Updated w CoCoRAHS snow-sleet accums.

3/31-4/8 may be of interest in the north half of our forum... we'll see if this holds. Combination of TC (both EPS/GEFS), weakening AO, NAO gradually heading neutral or negative, EPO heading neutral or negative, all for an extended period of time (at least a week) and the PNA possibly increasing a bit, may be the reason why the CFS is adding SD to the northern part of our area, inclusive of I80. CFS has had eyes on the 19th from time to time. I'll want to see the CFS keep this period of 3/31-4/8 in its sights (one or 2 significant wintry events) as we head toward the end of March.

Advisory situation may be coming to a portion of the forum-not a lock, for the Friday morning commute, despite probable less than official criteria amounts NYC/LI due to sharply falling temps to between 25-30F with sleet to snow in the 5A-8A time frame and gusty n-ne wind of 30-40 MPH. Snow ends sometime late morning-midday with temps recovering above freezing in the afternoon. Wind gusts for a few minutes between midnight and 8A could reach 50 MPH in parts of the area. Added wind event to the thread. Snowfall for NYC-LI T- at most 2", while a bit heavier seems likely I84 corridor extreme nw NJ of 1/2 to possibly 3". Think the best chance for 2+" in our subforum is CT. If the precip ends more abruptly, then we escape the advisory and amounts will be under 1" with the lesser snowfall of the 00z/17 cycle ICON, UKMET, 12K NAM considered. Note: this pgh on snow ratios added at 550A/17: as the transition to snow occurs, the first hour or two may be melting on most surfaces and certainly pack down to snow ratios less than 10 to 1, possibly closer to 7 to 1 or something like that. Some of the modeling has complications not only Friday, but also next Monday. For Friday, there could be two bands of halfway decent accumulative snow, one across I84 and the other just south of I78 across central or s NJ? TBD. Then, next Monday: the 00z/17 EPS and GEPS want to form a deep cyclonic circulation off the mid or south Atlantic coast this weekend and drift it north or northeast early next week, spreading rain back into the area. Depending on latitude of formation, will determine how much warming aloft occurs. ENS have 850 temps in the +3/+4C range next Monday, too warm for snow, provided all the excessive height rises and warming aloft that is modeled in the northeast occurs. If that shifts north, then there is a real long shot (very low chance) we might be looking at some marginal thermal profiles for a bit of wet snow in CT. At this time, I wouldn't be promising mostly clear skies and dry weather for Sunday afternoon-Tuesday morning. Added the 0841z/17 NWS ensemble prob for >1" of snow Friday. You can see the concern for going too heavy.

5 of the 6 OKX CLI locations had a T of snow yesterday (probably sleet or sleet-snow mix). Interesting bands of heavier qpf se NYS/CT and near-just s of I78 .Wonder if any zl- LI NNJ this morning? Anyway, should b almost done. CoCoRaHs added at 417P for this largely non-event, but at least the first widespread sleet/snow Trace's this March and back to at least Feb 27. Definitely short of what I expected to be an advisory event when threaded the 7th. At least modeling can tell when there is a risk 9 days in advance. Thread discussion should fill in any questions on modeling intent. GEFS/GFS initially far too far south, and probably a day or so fast. Otherwise V16 at times far too robust in the later stages of the approach to the 16th.

fwiw... flurries via mPING near Somerville, also e central PA into nw NJ. My last post for 3 hours.

wish.... cant get that exuberant. at 13z... it appears to me the GFS para (v16), RGEM, EC, 09z HRRR have had the best handle. Flurries all the way down to just no ILG and it appears to me some of our members in w NJ should have a brief snow shoer or ice pellets sometime near 1030-1130A. After that? am guessing emphasis on whatever wintry elements occur will shift to the I80 region northward.

I hope there is something behind this week for NYC, tho I don't see it right now. If NYC can't muster more than a T this week, the season might be done, barring extraordinary changes in the upper air pattern in April.

16/630A: Not much change from yesterday's post. System probably departs Friday but still a very small chance of departure complications.

626A/16: Not much. 00z/16 EC op and 06z/gfs v16 (para) are best chance of a little snow this afternoon-night, mainly n of I80. Doubt if NYC/LI can do more than T of snow-sleet if those elements occur. nw NJ might see spotty freezing rain showers tonight. Thread now converted to OBS-NOWCAST if and as needed.

So, let's briefly review 3/20 as the end of snow risk NYC? I don't see anything favorable til 3/27 and even then very-very low chance. Actually looks quite warm to me the last week of March. After that? any sign it can back below normal in early April? Thanks, Walt

548A/17: Advisory situation may be coming to a portion of the forum-not a lock, for the Friday morning commute, despite probable less than official criteria amounts NYC/LI due to sharply falling temps to between 25-30F with sleet to snow in the 5A-8A time frame and gusty n-ne wind of 30-40 MPH. Snow ends sometime late morning-midday with temps recovering above freezing in the afternoon. Wind gusts for a few minutes between midnight and 8A could reach 50 MPH in parts of the area. Added wind event to the thread. Snowfall for NYC-LI T- at most 2", while a bit heavier seems likely I84 corridor extreme nw NJ of 1/2 to possibly 3". Think the best chance for 2+" in our subforum is CT. If the precip ends more abruptly, then we escape the advisory and amounts will be under 1" with the lesser snowfall of the 00z/17 cycle ICON, UKMET, 12K NAM considered. Note: as the transition to snow occurs, the first hour or two may be melting on most surfaces and certainly pack down to snow ratios less than 10 to 1, possibly closer to 7 to 1 or something like that. Some of the modeling has complications not only Friday, but also next Monday. For Friday, there could be two bands of halfway decent accumulative snow, one across I84 and the other just south of I78 across central or s NJ? TBD. Then, next Monday: the 00z/17 EPS and GEPS want to form a deep cyclonic circulation off the mid or south Atlantic coast this weekend and drift it north or northeast early next week, spreading rain back into the area. Depending on latitude of formation, will determine how much warming aloft occurs. ENS have 850 temps in the +3/+4C range next Monday, too warm for snow, provided all the excessive height rises and warming aloft that is modeled in the northeast occurs. If that shifts north, then there is a real long shot (very low chance) we might be looking at some marginal thermal profiles for a bit of wet snow in CT. At this time, I wouldn't be promising mostly clear skies and dry weather for Sunday afternoon-Tuesday morning. Added the 0841z/17 NWS ensemble prob for >1" of snow Friday. You can see the concern for going too heavy. --- Strong cold high pressure approaching Quebec Friday-Saturday will combine with an eastward moving and opening closed low in the Ohio Valley, to permit a period of wet snow here on Friday. Duration and intensity are uncertain along with resultant amounts (T-2"?) and will be related to the proximity of the positive tilt 500MB trough. For now, this could be considered a back-back system, modeled way back as early as the 00z/7th modeling cycle, that could provide as much snow to the parts of the forum, as whatever occurs late 16-17. The fresh influx of colder BL air from the north may even allow measurable snow into NYC? Most of the modeling favors a few hours of snow Friday morning with marginal accretion temps. Still, for an event at the tail end of winter for NYC, it could provide a little fun? This especially if the GEPS-NAEFS solutions of keeping the low close enough to continue significant qpf going into early Saturday. Then we would be talking about some potentially plowable snow to near NYC, but this is an outlier possibility for now and best at this time (D5) to favor conservative ,minor impact, at worst. Finally, if this storm system does hang around nearby to our south all weekend (low chance), it might make a northward drift into the CT/LI part of the forum Monday the 22nd, but by that time, the snow temp profiles have warmed to rain (probably exhausted the snow profile cold air supply).

Will begin a low confidence thread for 19-early 20 by 630A. Below is my own view (lower than usual confidence) on what happens late Tuesday-early Wednesday. I78-I84 corridors-periods of light snow, sleet or freezing rain likely begin Tuesday afternoon or evening and ends as rain Wednesday morning. Modeling uncertain-so my confidence on how much ice/snow is less than usual. There is a pretty good chance of at least spotty icing in PA/NJ that may require treatments. If it's snow, just a slightest covering to maybe an inch or 2 but can't promise all snow except CT/MA. I can see the need for some caution traveling untreated surfaces Tuesday night-early Wednesday. One model group: The GFS v15/16 have been hitting the snow harder along w the GEFS, for se NYS/extreme nw NJ/extreme ne PA with potential for 4" high terrain, if no ice. One of my concerns is ice in ne PA/nw NJ. For NYC-LI: Even with snow snow or sleet in the air, NYC may not measure anything more than T if it's light. If it manages the 00z/15 GFS scenarios, then yes, minor amount there. Better chance spotty minor amounts LI (under 1"). Follow the models. I'd like to see models, other than the GFS, become more robust. For now, the 00z/15 GFS solutions are outlier heavier outcomes. I don't know what to believe but the uncertainty on qpf volume, as well as thermal profiles suggest conservative expectations.

Good Monday morning everyone. Here's my placeholder for the threads: Less than usual confidence on ice/snow amounts. Tuesday-Noon Wednesday: I78-I84 corridors-periods of light snow, sleet or freezing rain likely begin Tuesday afternoon or evening and ends as rain Wednesday morning. Modeling uncertain-so my confidence on how much ice/snow is less than usual. There is a pretty good chance of at least spotty icing in PA/NJ that may require treatments. If it's snow, just a slightest covering to maybe an inch or 2 but can't promise all snow except CT/MA. The snow may never reach Boston? I can see the need for some caution traveling untreated surfaces Tuesday night-early Wednesday. One model: The GFS v15/16 have been hitting the snow harder along w the GEFS, for se NYS/extreme nw NJ/extreme ne PA with potential for 4" high terrain, if no ice. One of my concerns is ice in ne PA/nw NJ. Friday-early Saturday (19-20): Mainly I78-I84 corridors: Rain Thursday should change to a 4-8 hour period of wet snow Friday morning with trace to 2" amounts on untreated surfaces, especially high terrain. There is a small chance that snow continues much longer, into Saturday morning, whereby we'd have a more significant snow accumulation problem, especially PA/NJ. Max gust here in this part of Wantage NJ on Sunday was again 43MPH~6PM.

btw...NAM is starting to join the fray, need the GGEM/RGEM coming up. GFS v15 and 16 now in for NYC-LI potential measurable. I sort of expect the EC to come back tomorrow. What ultimately happens, unclear, but some sort of wintry qpf is coming to a fairly large part of the forum Tuesday and probably again Fri. Late season: tougher accums but this thread continues in the game with a new one probable tomorrow morning if the EC/GFS can keep it lively.