Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 04 2025 23:04:37 AWUS01 KWNH 042304 FFGMPD MEZ000-MAZ000-NHZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-050502- Mesoscale Precipitation Discussion 0220 NWS Weather Prediction Center College Park MD 702 PM EDT Sun May 04 2025 Areas affected...Northeast PA...Central to Southeast NY...Portions of Southern New England Concerning...Heavy rainfall...Flash flooding possible Valid 042302Z - 050502Z SUMMARY...Concentrations of heavy and slow-moving showers will continue into the evening hours across portions of northeast PA, central to southeast NY and parts of southern New England. A threat for some flash flooding will continue given localized persistence of some of the heavier showers. DISCUSSION...Generally no change to the earlier MPD reasoning across the region. The large scale pattern across the Eastern U.S. features a deep layer cyclone over the OH Valley with an occluded surface low structure and a stationary front that extends east across central to eastern PA and into southern New England. A rather deep warm/moist conveyor belt continues to only slowly shift eastward with time along the East Coast, but continues to channel an axis of 1.25 to 1.5 inch PWs northward up toward areas of the northern Mid-Atlantic and southern New England. Radar imagery shows an area of slow-moving but locally heavy shower activity impacting areas of northeast PA through parts of central and southeast NY where recently there has been some rainfall rates reaching upwards of 1 to 1.5 inches/hour based on MRMS data. Meanwhile, with aid of the broader warm air advection regime, an axis of locally heavy rainfall is also noted from eastern NY over into far northwest MA, southern VT and southern NH. Much of the rainfall in general across the region is being aided by a combination of frontogenetical forcing and elevated instability. The best instability is along the front itself with areas of central and eastern PA seeing MUCAPE values of 500 to 1000 J/kg. Some persistence of locally heavy shower activity with some cell-training concerns will continue into the evening hours across the region with rainfall rates still capable of reaching 1 to 1.5 inches/hour where stronger convective elements near the front materialize. Some additional rainfall amounts of 2 to 3 inches will be possible locally. As a result, some additional localized runoff problems and flash flooding will be possible. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6ULHUzrxS2td6LtE2y5M5QBgytxA_aZ4B9cbbIBmnTpwPyYEe03qtSjl4qkavv5we0Y2= mnwA_ZlaGyXMv7DguogPcM0$ for graphic product... ATTN...WFO...ALY...BGM...BOX...BTV...GYX...OKX...PHI... ATTN...RFC...MARFC...NERFC...NWC... LAT...LON 43517287 43507113 43117078 42667137 42447252=20 41417381 41147528 41367594 42057599 43007480=20 =20=20=20=20=20=20=20=20=20=20=20=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) .