Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Aug 02 2024 16:46:40 AWUS01 KWNH 021646 FFGMPD MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-022242- Mesoscale Precipitation Discussion 0780 NWS Weather Prediction Center College Park MD 1246 PM EDT Fri Aug 02 2024 Areas affected...New Jersey/eastern Pennsylvania into southern New York State and southwestern New England Concerning...Heavy rainfall...Flash flooding possible Valid 021642Z - 022242Z Summary...With progression through the afternoon hours, increasing convective coverage and cell mergers/local training should promote at least a few areas of excessive runoff. Flash flooding is possible through 23Z. Discussion...Recent radar/satellite indicates a mature convective complex advancing eastward through central Pennsylvania currently. Abundant sunshine was occurring ahead of this complex, leading to surface-based destabilization. Additionally, newer convection over central New Jersey appeared to be focused along an east-west oriented boundary in that vicinity, with a weak wind shift also noted via surface obs in the area. Southerly low-level flow was maintaining an abundantly moist and destabilizing airmass across much of the discussion area, with 1000-2000 J/kg MLCAPE and 1.75-2 inch PW values noted per 16Z SPC Mesoanalyses. Both observations and model guidance depict gradually increasing convective coverage along and ahead of the eastward-moving central PA MCS through the afternoon. Convection forming out ahead of this MCS will likely foster a scenario favoring scattered to numerous cell mergers, which should locally prolong rain rates and result in occasional 1-2.5 inch/hr rain rates in a few locales.=20 Some concern also exists that cell mergers could become focused near the aforementioned low-level boundary (currently extending from Allentown to New York City) as it lifts slowly northward during the afternoon. This area happens to be located near relatively low FFG thresholds (in the 1-1.5 inch/hr range), suggestive of isolated to scattered flash flood potential. A secondary area of concern exists across south-central New York State where similarly low FFG thresholds exist and heavier downpours should overspread the region in the next 2-3 hours. Given the aforementioned scenario, flash flood potential exists and is locally highest from northern New Jersey/northeastern Pennsylvania northeastward into southwestern New England. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6pDKiR6_f2AN_8wM8g8Rw-6ce8Kfs0S4_wa8S205LiWknWuYxDb55isPoy0FxYBT9Uuf= L4Vkcz_gObQp5G7fA4yKpeU$ for graphic product... ATTN...WFO...ALY...BGM...BOX...CTP...GYX...OKX...PHI... ATTN...RFC...MARFC...NERFC...NWC... LAT...LON 43007325 42827220 42417197 41877207 41537256=20 40867309 40327406 40067520 40157631 40797661=20 41607699 42137707 42667623 42987411=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .