wdrag

Thanks... March 2001 was not a highlight of my career. We lucked out in EMA/RI but definitely missed the front end. I think it was that storm botch from PHI newd, that helped accelerate the change to a collaborative effort with WPC and soon the implementation of ENSEMBLES, to ballpark our forecasts and limit the extreme solutions. I definitely think that has helped me, and possibly many others, be more realistic about the forecast-a benefit for the users of weather info. Thanks again!

Good Tuesday morning everyone, I've an errand to run shortly so I'll start the thread for 25-26 only at about 9A. Still fraught with uncertainty but looks cold enough for any qpf to be a snow or ice mix except the usual mess for LI, with an ice/snow line in my mind either I78 or I195. SOOOOO early so will probably play it a loose and tighten up the topic as the days move along. Later, Walt

This may be getting a little more interesting for ne PA/se NYS/n NJ/ LI/s CT Wednesday morning, Probably worth monitoring for a small accumulation within 4 hours of sunrise Wednesday. Some of the modeling is trying to combine the cold frontal trough instability snow showers with an area of weak low pressure moving off s NJ. No consensus on that occurrence. Otherwise the cold frontal surge of instability changes, spikes in RH etc as discussed yesterday prevails. If it doesn't snow by Noon Wednesday, then the afternoon snow showers will be gradually drying out to virga in the gusty northwest flow of drier colder air. Right now I expect fairly widespread coverage of dustings to 3/4" ne PA/n NJ/se NYS/s CT - LI including NYC. Whether it's more than a trace NYC or observed officially before melting (NYC mostly 8A-11A), that i don't know. If the 12z and beyond cycles of the RGEM/HRDPS drop it, then I've hit this too hard.

I had to run some errands... , so rather than have anyone wonder, I just delayed til tomorrow. After review of the 12z/18 NAEFS (available ~230P/A) we continue on target as outlined this morning around 6A... advisory snow/ice with most of this on the 26th but as you say, not only a piece possible on the 25th, it could wait til late 26/27. Think this can wait til 6A ish/19 and get off the fence and topic at that time. That will still be 6-8 days in advance, so the uncertainties are likely to persist-will run it broad but give us the probable blended outcome. NAEFS continues colder thicknesses and BL temps along I95 so not too bad, despite the differing model solutions. From my view, IF we do get 0.4" frozen qpf up here...where sleet doesn't occur, there might be some larger snow water ratios of 12-13 to 1 instead of our typical 10-7 to 1 along the coast? Will havre to check some guidance on that. I like the LF quad of 2H jet.

No thread from me this afternoon on anything here 1/25-26 etc. Solutions too variable and there seemed to be a large southward displacement since the 00z cycle. Have no idea if that will hold firm. Will rereview in the morning.

Likewise here in Wantage around 145P... brief. just wet. Thanks!

Snow showers on their way for parts of nw NJ, se NYS and CT... see radar sewd moving. Probably a dusting-coating for terrain above 1000 feet. sleeting near NYC recently. I'm 38.8/29.8. Just too warm to show snow on grass but thats at 700 feet. Cooler at 1000 feet. This is a potentially a tease for stronger activity sometime Wednesday morning-midday.

Thank you Don, I don't have BUFKIT because of my MAC and so get by with Tsecs, R#, and various gust algorithms. On dustings coming soon to nearby yards in our forum. Not sure if anyone noticed the dew point isn't dropping. That's a very good sign that we'll have enough low lvl RH to support snow showers making it to the surface. A few graphics follow that focus here near NYC 6A-2PM Wednesday. My dewpoint has been sitting around 30 since late yesterday. Where they measure 1/4-1/2"... within10 Mi of CP?? Here's the 12z/18 FOUS. Note T1-T5 lapse rates over 15C and ... strong stability change (drying out late Wednesday afternoon +15C change from 18z/20-00z/21). That and the wind shift-cold pool aloft should result in a chance of measurable SPS snow showers down to LI. Used the NAM12K. 3K not quite as impressive but still notable. ICON, RGEM and recent EC have it in or within 15M of NYC. I don't expect the GFS to be as clear cut. The HRRR per NWS friend telcon is supposed to shine in convection. Not summer, but this is convective signal. Here's the12z/18 HRRR model for 12z Wednesday...bearing down from the nw. Let's see if this risk diminishes or materlializes. I'm thinking this will happen but whether CP gets more than flurry?? But it could drop briefly to 3/4mi? We'll see what gives. IF the dew point can hold near 25F through 12z Wednesday... I like the odds. I also added for those unfamiliar: credit to the online met and his support group... the FOUS interp guide. Most people probably don't use the FOUS to their advantage. It's a good tool to have for a quick idea. Back at 4PM for a new thread to take into account NEG NAO impressions and others, plus my own reevaluation for a new thread (25-26 and or possibly 27).

NYC CP: While I expect scattered dustings to ~1/2 snow shower accumulations this week in parts of the I84 corridor down to just north and and west of NYC, the chance of CP seeing 0.1" snowfall in time for an observation is rather low. It's a matter of timing any snow shower with temps cool enough to allow accumulation and the observer to record it. The only reason for any attention to such a minor occurrence, is that it hasn't measured snowfall here in CP since the storm of the 16th-17th December. Instability and changes in instability with a trough passage both surface and aloft will be notable Wednesday (th instability already is). A NAM TSection check is showing the cold pool aloft and the RH spike but only a smattering of measurable around the NYC forum so odds favor no occurrence of 0.1" snowfall in CP. Already, late today, the snow showers sliding out NYS and PA from the west northwest may turn to sprinkles as they approach the near NYC environs but it will be colder Wednesday for a much more likely sustaining of flurries or even a snow shower into NYC or LI. Haven't studied Thursday-Friday, as it's a minor chance as it stands now-still possible but not a probable measure for NYC CP.

Good morning all, My take based on the 00z/06z ops and 00z/18 ensembles. 00z/18 NAEFS helped guide the wintry and qpf call (~0.4" w-e I80 axis) The I84 corridor has basically scattered dustings this afternoon and evening, Tuesday afternoon-Wednesday afternoon, and again Thursday-Friday. Amounts in the Poconos might add up to 1 or 2 inches by Friday, trace to 1/2 inch elsewhere by Friday eve. Basically just be alert for quick changes but overall no big deal. Travelers into the northeast USA Monday-Tuesday the 25th-26th should be aware that an extensive light to moderate hazardous wintry episode is expected for all untreated surfaces, especially the I84 corridor. It may even briefly begin as snow-ice down to Philly Monday. The front end Monday start time is uncertain..it could start for a couple of hours Monday morning then stop for 12 hours. The bulk of this event probably occurs late Monday night into Tuesday night the 26th. Odds favor a change to rain south of I80 by Tuesday morning the 26th, but ice or snow north of I80, especially the I84 corridor. NYC-LI--- have no confidence on sleet-snow start or just rain...close but for now both are options, from a multiple model blend. Right now, I think most of the wintry is to the nw-ne of NYC, though a start as wintry is possible. I'll probably start a thread on this, this afternoon pending receipt of the entire slate of guidance. I do see the para is south and that the EPS ensembles are south. I just think there is enough ensemble data for an event of sorts. Will check back mid afternoon.

GFSV16 has started for the 12z/17 cycle. at 24 hours as of this post.

Added from the American Meteorological Society (AMS) Dec 2020 Digital edition. I think they would like to see this info shared and I think it valuable...especially Lead Time on SVR and Synoptic Scale events. It definitely supports my basis for acting on threads. This is from page 1125. AMS STATEMENTS Priorities for a New Decade: Weather, Water, and Climate A Policy Statement of the American Meteorological Society (Adopted by the AMS Council on 28 September 2020) One to three hours. Our national investment in research and observations has paved the way for severe weather guidance to extend beyond traditional 30- to 60-minute warnings into the 1- to 3-hour time frame. Such guidance could lead to major benefits in preparation and safety. It also raises new questions. How will people respond if they expect to have more than an hour to take action ahead of a possible tornado or a flash flood? How can the probabilities and uncertainties inherent in such guidance best be conveyed? How can schools, workplaces, and other institutions act to support public safety measures in these extended time frames? Weeks to months. Specific local weather forecasts cannot be issued with accuracy beyond about 10 to 14 days. However, many other types of outlooks have demonstrated accuracy over periods of weeks to months (subseasonal to seasonal periods) when they are presented in terms of probabilities or likelihoods. For example, some periods of increased regional tornado risk Predicting and respond- ing to such multipronged threats will require new forms of collaboration and data sharing across sectors and disciplines.

Thanks... still learning. It's tough to be realistic ...but in forecasting, credibility goes to crud pretty quick if you miss more than the coin flip. Good to discuss everything as is done on these forums.. helps me see data use that I'm not up to speed on. Speaking of which: watch those lapse rates this week and R1(boundary layer RH aka Temp-dew point spreads less than 20F)... We'll have to see if downslope dries out the potential for snow showers all the way down to the city. I like what I see but models and MOS are pretty dry so that tempers my enthusiasm. Plus the observation process might miss the tiny sub one quarter inch amounts. Making the most out of this winter pattern.

On frigid weather - enjoyment of-- cause some of us lived through it (we're older but still alive). I think there was the 30 days or so of subfreezing weather in NYC that contained the damage of a January garbage strike back in the 60s. How about pond hockey regularly every winter in the 1960s. how about the wonderful chill of the freezer NFL bowl in Jan 82 ... that was some pretty decent cold. I remember MKE Jan 1982... two separate super cold episodes out there where electronic means were needed to keep the oil in your engine from congealing (ie so you could drive to work). and I know one of those shifted episodes into the northeast USA. BRRRR... and that's why I own too much long under and outer wear. Now that was ARCTIC... The were the days in the northern USA...

As of 7AM Sunday 1/17 I have no changes to anything written since inception of this thread. No increases, no decreases. It's minor if it occurs. I sort of like Wednesday morning when I think we could see pretty decent lapse rates and a decent short wave passage. The possible snow or flurry event for late Thursday-early Friday is more WAA related, after what should turn out to be a pretty cold Wednesday. Hdre's the 06z/GEFS membership and mean as well as the anomaly modeled for 18z Wednesday.

Good Sunday morning everyone, Jan 17. No insight except my own interp of what the models are trying to say up here. No big deal til the 25th and even then, quite a bit of uncertainty, including ptype along I80-LI. I84 corridor Today-Tuesday... a few flurries and maybe one or two short periods of minor accumulative snow showers, especially Poconos Monday-Tuesday where dustings are probable. I84-I80 corridors including LI Wednesday morning-early afternoon including LI: COLD. A period of flurries seem likely or even minor accumulative snow showers. I84-I80 corridors including LI Thursday afternoon-early Friday: A period of flurries or minor accumulative snow showers, except possibly sprinkles-light rain for LI. 25th-26th: No 06z V16 as of this writing and the 06z op was scary dry. NAEFS has a widespread light event of snow or ice I80 northward (Rain LI?). Not convinced yet of the NAEFS amounts of 0.4" melted. Could be less. Have a good day and let's cross fingers for something.

Have no additional contributions on the 22nd. the 25th-26th yes. Notoriously, Modeling doesn't handle ejection of the sw USA 500MB closed lows very well. Impact differences are huge in the eastern USA. Think I want to wait 3 more days (19th before getting my hopes too high).

Not too worried about the 25th-26th...something should happen. I am paying attention to this Thu night-Fi. Doersbt mean it will happen but surprised the GEFS is up a little on qpf.

I like the conversation and my only thought with the 26th, watch the 22nd. For those who wish NIL for the 22nd.. root for the 12z/16 GEFS to back off a bit on qpf and for UKMET to not have developed some sort of short wave in the Ohio Valley to join with the northern tier ese driver. We'll have to count on this being one of the UKMET'S spurious wrong off by 300 miles on qpf axis operational cycles. It does this kind of thing...am saving the UK for qpf for 12/22 night/23 AM for a future compare. I'll be away from the computer for awhile after 1P.

Snowfall reports so far, extreme northwest portion of the forum area as of CoCoRahs reports this morning prior to 830AM.

Wantage NJ (this part) 0.76 and still clicking a bit.

Good Saturday morning everyone, Jan 16. Bringing this back briefly to upcoming wintry weather: If you want winter, maybe a trip the next 7 days to the L Ontario snow belt. Added a map of this mornings NWS forecast for an idea of where to try and an idea of amount max regions. This just goes on and on this week and looks to me like they are assured of a pretty good snow mobile season well into early February, at the least. Will not add NAEFS maps for what looks to be wintry qpf the 25th-26th, since I'd like to see this continue another couple of cycles. Just too early for me to start a topic (from my view). The previous discussion concerns, including ripping jet across the USA, blocking suppression etc. First, I'd like to see us get something minor this week associated with the Wednesday and late Thursday short waves. Finally, while this excludes most of us, there should be scattered or isolated high terrain dustings/coatings of snow I84 corridor later today through Monday (500MB troughs passing eastward through the northeast USA). Have a day.

Basically no change to this topic since reviewing the 00z/16 OP's and ensembles. EC is our best model bet right now. I could have added a chance that the events for Li might be rain for Thursday, but I don't think so. Yet that is a possibility. What I do think is that there will be at least an hour or two of snow showers for parts of the forum, especially this coming Thursday.

Topic started to follow whether or not NYC can muster it's first measurable snow since December 17. Other parts of the forum had some general snow on the 3rd. Lots of debate on what will happen, or not, so we might as well have some fun tracking it and keep the 25-26th and beyond out of this topic. First measurable snowfall (near climo) POSSIBLE between Tue night and Thursday night. Two opportunities and both could be suppressed/dried out in northerly flow. Also could be too warm to stick in NYC if snow were to occur, and especially if it occurs during the daylight hours. These are probably minimal impact events, if any. Guidance probabilities are possibly conservative for short periods of light snow in a 12 hour period, especially with currently expected melted qpf under 0.10. Opportunities are associated with an esewd moving shortwave from the Great Lakes to new England early Wednesday and another esewd moving short wave from the Great Lakes late Thursday. Climo snowfall for this during the 'climatologically' coldest winter average temps in NYC: CP 0.2-0.3; POU 0.4.-0.5". Short events. As of this 1/15 412PM start, probably under 8 hours total, possibly less than 1 hour in parts of the area? I would hope we can muster half an inch between these two short wave passages in part of our NYC forum, be it se NYS, CT, e LI or maybe we get lucky for much of our forum? I'll be glad to adjust this topic with any interesting information that is added from our group and of course if the models somehow improve our chances which right now, per 12z/15 (Friday) NWS MOS and WPC extended, are less than 50%.

Hi everyone, Think I'll start a topic to track some stuff. Lots of debate on what will happen, or not,. So we might as well organize it and keep the 25-26th and beyond out of this topic. It's probably minimal impact events, if any. First measurable snowfall (near climo) POSSIBLE between Tue night and Friday morrning. Two opportunities and both could be suppressed/dried out in northerly flow. Also could be too warm to stick in NYC if snow were to occur, and especially if it occurs during the daylight hours. I do think we'll see a little bit of measurable snow in parts of the forum from the esewd moving shortwave early Wednesday and/or from the east or esewd moving short wave for Thursday afternoon-eve. Climo snowfall in NYC CP is 0.2-0.3; POU is 0.4.-0.5". Short events. As of this 1/15 post, probably just 2 to 6 hours. I would hope we can muster half an inch between these two short wave passages in part of our NYC forum. (north and northwest fringe high terrain our our forum may do that tomorrow into Sunday with an inch or 2). For NYC this would be the first measurable since Dec 17. Other parts of our area had measurable around Jan 3. I'll be glad to adjust this topic with any interesting information that is added from our members and of course if the models somehow improve our chances which right now, per 12z/15 (Friday) NWS MOS and WPC extended, are less than 50%.