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RU848789

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Everything posted by RU848789

  1. RU848789
    Ignore it, like the NAM, at this range - it's a regional/mesoscale model...
  2. RU848789
    Yep, he's fairly pessimistic on the 95 corridor and SE of there...
  3. RU848789
    Y'all are falling down on the job, lol. I've been away (playing disc golf) for several hours and I come back to a great GFS run that came out an hour ago and nobody posted this map? It's not the JMA or the Chilean model, c'mon. More seriously as many of us have been saying, let's see what we get at 18Z/0Z tonight after all the players are being well sampled by the RAOB network. Maybe the GFS will be an outlier, maybe not, but I'd rather have it in the snowier than before camp.
  4. RU848789
    Thanks, that's very nice of you to say.
  5. RU848789
    The Pivotal page is definitely well done, but they acknowledge that in marginal temp situations it's simply very difficult to translate the "snow that falls" to the "snow that accumulates." Also, as I've discussed many times over the years, Kuchera is very simplistic (it simply takes the warmest temp in the air column and has a simple algorithm reducing ratios based on that temp only) and doesn't account for snow crystal shape impact on accumulated depth nor snowfall intensity, which can easily overcome melting in some situations. IMO, as someone with significant expertise in crystallization, heat transfer and phase change dynamics, the biggest "miss" in that page is not accounting for intensity, nor the fact that once there is some accumulation on a warmer-than-32F surface, the "new" surface is now snow/slush, which, by definition is then 32F, meaning subsequent accumulation of snowfall will no longer be significantly impacted by melting on that surface, plus air temps a few degrees above 32F will have a very small melting effect, since heat transfer via air to the snow is far less than from a solid (the ground) or liquid (e.g., wet ground/puddles), due to the huge density difference, primarily (air is far less dense, which is why the heat transfer coefficient is about 20X less from air than water, for example - that's why one can kep one's hand in a -10F freezer for minutes, but can't keep one's hand in a 32F cooler filled with ice/water for more than a few seconds). This is why we can see snow accumulate quite well at high intensity in April during the day with ground and air temps well above 32F - and we're not going to have ground or air temps that far above 32F in this case, plus we're not going to have any solar insolation issues for most of the storm, at night and even during the day, as the sun angle is still quite low, so we're not going to need high intensity to accumulate well (just moderate intensity most likely, although high would be better, of course). I'm not saying we're going to see 10-15:1 snow to liquid ratios (which is what we'd likely get with good dendritic growth we're likely to see where the snow crystals are being formed, if that snow didn't encounter above 32F air in the column nor above 32F ground), but I am saying getting to 8-10: ratios shouldn't be that much of a stretch, as long as we have decent intensity.
  6. RU848789
    I'd say we have a slight improvement, lol, across the board from 12Z to 0Z for the vast majority of the subforum and even from DC to Boston (except for areas well NW/inland, but they haven't had close to 0" of snow since 2022). Better confluence, colder air, better track. Now let's see if we can maintain this kind of consensus for a significant to major snowfall over the next 4 days - crossing fingers and I'm not superstitious, lol.
  7. RU848789
    Colder/snowier. 4 for 4 tonight...
  8. RU848789
    Every model, so far tonight, has made significant increases in snowfall amounts for almost everyone in the 95-corridor and towards the coast, as well as nearby NW suburbs. Now we wait to see what the Euro says and if we can maintain such a snowy forecast through the next few days and actually see the snow. Really would love to see the forecast/track hold after all the players are within the RAOB network sometime tomorrow (hoping we're not missing some key initialization data).
  9. RU848789
    Correct. Here it is if interested. Also, the link below has a very nice summary of what the model consists of, especially with regard to the various model inputs which get "blended" in the BOM (they're not all equal). https://luckgrib.com/models/nbm_conus/
  10. RU848789
    So, what do we have to do to make this happen? Damn this looks nice, even if it's 5+ days out.
  11. RU848789
    Good points. To amplify further, one thing most don't appreciate is that with moderate to heavy snowfall rates, ground melting will be overcome quickly and once there is a layer of snow on the ground, that snow, by definition is at 32F (or colder), meaning subsequent snowfall has a negligible melting rate, even if the air temp is a degree or two above 32F. Also, sun angle is quite low and antecedent temps will likely be not far above 32F, so initial ground melting will likely be quite low anyway. I also remember the old E/E rule (Euro/ETA - old name for NAM). Let's just hope we get snow (the vast majority around here want that, lol).
  12. RU848789
    Yeah, couldn't care less whether we have a significant snowfall which is washed away 3 days later - I just want to see some decent friggin' snow for the first time in a long time.
  13. RU848789
    Really liked Upton's discussion today... Attention then turns to the second half of the weekend. While there is a general agreement on a potential storm system to pass near the region Saturday night and Sunday, confidence is very low on any specific impacts including precipitation types, precip amounts, and winds. The exact timing is uncertain, but appears to occur sometime Saturday night into Sunday/Sunday night. The 12z deterministic and ensemble suite includes scenarios that give the area an all snow event, a mixed precipitation event, or one that has at least the southern half of the area in plain rain with potential of wintry precip inland. There are also solutions that indicate the system passing far enough south that little to no precip occurs in the CWA. It is important to stress that any of these solutions are possible, but we cannot say with any confidence which one will occur. The model guidance is likely to waiver many times in the next several days as the main southern stream energy is still over the north central Pacific. The energy looks to reach the western US Tuesday night into Wednesday. The evolution of the northern stream over southern Canada is also important to the outcome from this potential system. The NBM does indicate a respectable 70 percent chance of measurable precip (greater than 0.01") during time frame, and about a 50 percent chance of greater than 0.25". Deciding to Cap PoPs off at 50 percent for now given that it is still just under a week out. Precipitation types will be fine tuned as models converge and forecast confidence increases.
  14. RU848789
    Faster system, precip arrives after dark, plenty of snow, verbatim. Significant snow on the table is all I'm looking for at this point.
  15. RU848789
    6 pages for a storm that's 6+ days out in an extremely fragile setup, which could easily miss us or just rain on us (along 95), tells us how snow-starved we all are. I just like the fact that there's some chance of getting decent snow and something to track for a change. We are certainly due for a little luck after watching every threat fizzle last winter and we haven't even had any real threats so far this winter.
  16. RU848789
    The NWS Philly cancelled the wind advisory as of about 10 pm, as they're not seeing the high winds aloft mixing down to the surface as much as expected. There will still be gusts to 30-40 mph, but those are below advisory criteria. Lots of rain still to come, especially along and SE of 95. There is a strong low level jet, generally 40 to 50 kt, along the New Jersey coast, but the strongest winds are not mixing down given how warm the ocean is. Surface obs near the coast are generally reporting 30 to 35 mph gusts. Will go ahead and cancel the Wind Advisory, these winds are below Wind Advisory criteria.
  17. RU848789
    Latest NAM still wants to bring accumulating snow to the 95 corridor, but it stands alone, as no other models show more than a dusting to an inch or so outside of areas well N/W of 95 with only areas like higher elevations of the Poconos, Sussex and interior SENY getting more than an inch. Would be a coup if it verified. I'll be happy with mood flakes and maybe a dusting in the Edison area.
  18. RU848789
    I understand it's unlikely, but at some point, with both the NAM and GFS showing several inches of snow down through the 95 corridor, (except for the perfect snowhole over NYC metro on the GFS) one has to wonder if there's some chance they're on to something and maybe we could get some white stuff. Stranger things have happened...
  19. RU848789
    Had a few flurries at Allaire State Park in Monmouth County around noon (was playing disc golf there)... As an aside, CPK hit 30F on 11/25 its first temp AOB 32F, but I don't recall any freeze watches/warnings - did I miss that somehow?
  20. RU848789
    Thanks, did know that, but was more looking for hourly output from the globals and NAM/RDPS, even though the higher resolution convection allowing versions of those (NAM3K and HRDPS) are available hourly, as you noted - but I've observed that sometimes the lower resolution versions do better with non-convective systems like this one. And TT does have the HRDPS, which is hourly. Would also be nice to have IBM's/TWC's GRAF model output somewhere, which supposedly has very good accuracy scores, but I haven't seen it available anywhere (some media outlets use it though) to the public.
  21. RU848789
    No offense, but for me and thousands of others, the primary issue is the RU game in Piscataway, with tailgating from maybe 7 am to noon, which looks mostly dry on most models (maybe 0.05-0.1" before noon), but then the steady rains look to move in sometime in the 12-2 pm timeframe on most models (kickoff is noon), so the timing is really critical for fans and there is definitely significant variability on QPF starting around 2 pm, with some models showing 0.1-0.2" from 2-5 pm while others show closer to 0.3-0.4". My one big question for folks is where can I find hourly precip forecasts from the models (even if it's a pay site)? Pivotal premium only has 3 hr increments on some models and 6 hr increments on others and I'd love to see finer output. i know I can get hourly once the HRRR and RAP are in range, but it would be nice to have that, too for the globals and NAM/RDPS. Thanks...
  22. RU848789
    Models keep bouncing around for total event QPF, but narrowing down on 1/2-1" from maybe 78 to 84 and 1-1.5" from 78 down through SNJ/SEPA. NWS calling for a general 1-2" in most locations, including NYC, so they're a bit more bullish on the rain. For me the issue is the RU game in Piscataway, with tailgating from maybe 7 am to noon, which looks mostly dry on most models, but then the steady rains look to move in sometime in the 12-2 pm timeframe on most models (kickoff is noon), so the timing is really critical for fans and there is definitely significant variability on QPF starting around noon, with some models (6Z NAM and RDPS) showing no rain through 2 pm and very little rain through 5 pm, even, while other models are showing 0.1-0.2" through 2 pm and maybe 1/4-1/2" total through 5 pm. The NWS has about 1/4" through 2 pm and almost an inch from 2 pm to 8 pm in their hourly graphic. For most people the difference between 0.1" and 0.3" of rain is inconsequential, but not for fans out in the open. Crossing fingers for the NAM/RDPS to be right.
  23. RU848789
    As the rainfall graphic below shows, the amount of rain east of the Hudson in NYC/SENY and just off the NJ coast (except some very heavy rains at the immediate coast and just into NJ across from the Hudson) has been incredible, with the following highlights from the story linked below. There will likely be parts of that area that get 7-9" of rain, which is 2 months worth in one day. https://www.cnn.com/2023/09/29/weather/new-york-city-northeast-rain-flood-forecast-climate-friday/index.html In Brooklyn: A month’s worth of rain, up to 4.5 inches, fell in only 3 hours on Friday morning, according to National Weather Service data. This three-hour rainfall total is only expected about once every 100 years in Brooklyn, according to NOAA estimates. In Manhattan: Nearly 2 inches of rain fell in one hour in Central Park, the second-wettest hour there in 80 years. More than 5 inches of rain have fallen there so far. In Queens: It’s a top-10 wettest day at John F. Kennedy International Airport, where more than 4 inches of rain has fallen since midnight.
  24. RU848789
    Yeah, the Euro ensemble mean shifted west about 60 miles from 12Z (but 0Z last night was even about 60 miles further west), with obviously more members hitting west of Maine.
  25. RU848789
    12Z Euro landfall about 100 miles NE of 0Z, so it's looking like 0Z was a bit of a blip and not a trend...
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