Jump to content

bluewave

Members
 View Profile  See their activity

  • Posts

    35,351

  • Joined

  • Last visited

 Content Type 

Everything posted by bluewave

  1. bluewave
    I was in SW Nassau back on LI not far from JFK and only picked up 9”. That storm probably had the greatest rates under that epic 50 DBZ band of any snowstorm in the modern doppler radar era. https://journals.ametsoc.org/view/journals/wefo/29/6/waf-d-14-00056_1.xml Abstract On 8–9 February 2013, the northeastern United States experienced a historic winter weather event ranking among the top five worst blizzards in the region. Heavy snowfall and blizzard conditions occurred from northern New Jersey, inland to New York, and northward through Maine. Storm-total snow accumulations of 30–61 cm were common, with maximum accumulations up to 102 cm and snowfall rates exceeding 15 cm h−1. Dual-polarization radar measurements collected for this winter event provide valuable insights into storm microphysical processes. In this study, polarimetric data from the Weather Surveillance Radar-1988 Doppler (WSR-88D) in Upton, New York (KOKX), are investigated alongside thermodynamic analyses from the 13-km Rapid Refresh model and surface precipitation type observations from both Meteorological Phenomena Identification Near the Ground (mPING) and the National Weather Service (NWS) Forecast Office in Upton, New York, for interpretation of polarimetric signatures. The storm exhibited unique polarimetric signatures, some of which have never before been documented for a winter system. Reflectivity values were unusually large, reaching magnitudes >50 dBZ in shallow regions of heavy wet snow near the surface. The 0°C transition line was exceptionally distinct in the polarimetric imagery, providing detail that was often unmatched by the numerical model output. Other features include differential attenuation of magnitudes typical of melting hail, depolarization streaks that provide evidence of electrification, nonuniform beamfilling, a “snow flare” signature, and localized downward excursions of the melting-layer bright band collocated with observed transitions in surface precipitation types. In agreement with previous studies, widespread elevated depositional growth layers, located at temperatures near the model-predicted −15°C isotherm, appear to be correlated with increased snowfall and large reflectivity factors ZH near the surface.
  2. bluewave
    The only tears experienced from a weather event was missing the Nemo jackpot zone of 6”+ an hour and 50 DBZ radar reflectivities leading to 30-40” in CT. All this weather forecasting and analysis stuff is purely technical with no emotions involved. I save the emotions for the actual event.
  3. bluewave
    EPS coming around to the GEFS idea of a stronger MJO 4 as it struggles with the barrier effect when dealing with convection near the Maritime Continent. New run Old run
  4. bluewave
    This happens all the time with rainstorms but many just pay attention to storm tracks and exact amounts when the chance of snow is involved.
  5. bluewave
    Yeah, it had an epic run from Sandy to Nemo. But struggled with Boxing Day in that short range run that went too far east while the GFS was correct further west. Believe it did better with the storms the previous season. Wish they would create a model skill score just for East Coast storm tracks. Bet the Euro and EPS would score lower than the headline global skill scores which always get touted.
  6. bluewave
    They were too amped with the January 2015 blizzard and too suppressed with the January 2016 blizzard.
  7. bluewave
    My only issue with the Euro and EPS after the upgrades around 2014 and 2015 is how erratic the model has been with east coast lows. We have either seen outright long range suppressed solutions which correct NW closer to storm time. At other times there have been overamped lows with are modeled too deep and get weaker and more strung out closer to storm time. I used to really like the model for EC storm tracks in the period from Sandy to Nemo. But something really changed with the model after that period.
  8. bluewave
    Yeah, two issues in play. The actual ratios and the raw model cold biases. But even the MOS numbers have been too cold at times this winter. That’s why I wouldn’t even think about specific accumulations until under 72 hrs or even 24 hrs in a marginal situation like this.
  9. bluewave
    I never said that it couldn’t snow. Just that those 10:1 charts look overdone for such a marginal airmass.
  10. bluewave
    A good cold air source wouldn’t have highs in the upper 30s. Marginal air masses leave less leeway for significant snowfall from short term model changes.
  11. bluewave
    I don’t trust those 10:1 charts in marginal temperatures.
  12. bluewave
    It would be great if we had the cold airmass that we did in 2020 for this storm. Highs in the low 30s and lows around 20° have produced some memorable snowstorms for us. Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Snowfall 2020-12-16 31 24 6.5 2020-12-17 33 24 4.0 2020-12-18 32 24 0.0 2020-12-19 32 20 0.0
  13. bluewave
    The 0z EPS has a stronger trough in the West now so it has a warmer pattern for our area.
  14. bluewave
    Why would you ignore a cold bias which has been showing up all season?
  15. bluewave
    Because both sets of solutions are showing the same challenges with the warm air. The first challenge is a more wrapped up system which could correct NW under 72 hrs. The GFS has the 2nd challenge with a trough in the West pumping the ridge and temps in the mid 30s. But it takes longer for the system to consolidate so the surface low is weaker. While it’s still too early, the RGEM is weaker and more strung out with the low than the GEM near the end of it’s run.
  16. bluewave
    It’s tough to rely on those 10:1 maps with marginal temperatures as the positive snow depth charts are much lower.
  17. bluewave
    The GFS has a weaker and further south system so it can’t draw enough cold into the storm. The ridge ahead the storm was still strong enough so temps are in the mid 30s.
  18. bluewave
    That historic January Arctic outbreak produced the all-time 2nd coldest temperature on record at Newark. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Lowest Min Temperature Missing Count 1 1933-1934 -14 0 2 1984-1985 -8 0 3 1981-1982 -7 0 - 1942-1943 -7 0 4 1935-1936 -4 0 - 1934-1935 -4 0 5 1993-1994 -2 0 - 1976-1977 -2 0 - 1962-1963 -2 0 - 1960-1961 -2 0
  19. bluewave
  20. bluewave
    Tough situation for the Northeast coming off the wettest December and calendar year at several locations.
  21. bluewave
    Yeah, the NW trend is your friend if the forecast track is starting out far enough southeast in a more favorable pattern for coastal snowstorms.
  22. bluewave
    My guess is that it’s related to the Gulf Stream warming over the last 40 years.
  23. bluewave
    It doesn’t have to since just having a trough in that location usually leads to the models correcting stronger with Southeast ridge the closer in time we get.
  24. bluewave
    The trough is more consolidated near the Four Corners. The GFS forecast sounding is likely underestimating the warming near the coast with such a strong easterly LLJ off the Ocean.
  25. bluewave
    Stronger Southeast ridge this run leading to warmer storm track for the coast. This was expected with the trough in the West. New run Old run
×
×
  • Create New...