Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 03 2024 17:06:59 AWUS01 KWNH 031706 FFGMPD CTZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-032305- Mesoscale Precipitation Discussion 0790 NWS Weather Prediction Center College Park MD 106 PM EDT Sat Aug 03 2024 Areas affected...eastern Pennsylvania, southern New York state, New Jersey, northern Delaware, much of Maryland Concerning...Heavy rainfall...Flash flooding likely Valid 031705Z - 032305Z Summary...Scattered thunderstorms will continue to overspread the area from west to east through 23Z, causing spots of flash flooding. The areas of greatest concern for possible impacts extend from Baltimore/Philadelphia northeastward to Newark and across northeastern Pennsylvania. Discussion...Deepening convection continues in earnest primarily across central and eastern Pennsylvania currently. The storms are embedded in appreciable (30 kt) southwesterly flow aloft while being aided by 1) ascent from an approaching mid-level wave over northwestern Pennsylvania and 2) a moist, destabilizing airmass characterized by 1.5-1.9 inch PW values and MLCAPE values now approaching 2000 J/kg. Mainly cellular convective modes have been observed via radar mosaic imagery, although localized backbuilding has been noted in a few spots, increasing rain rates to around 3 inches/hr on an isolated basis. These storms are expected to continue developing eastward through the discussion area over the next 6 hours while exhibiting modest upscale growth into clusters and linear segments. Local training/backbuilding will continue to promote local areas of 2-3 inch/hr rain rates at times on an isolated to scattered basis. Some parts of the discussion area are more susceptible to flooding than others. The areas of greatest concern will extend from the urban corridor of I-95 from Baltimore/Philadelphia northward toward western suburbs of New York City along with portions of northeastern Pennsylvania. Many flood-prone, hydrophobic surface are located in the urban areas. Meanwhile, a few spots received 1-3 inches of rainfall across these areas and wet soils are likely contributing to lowered FFG thresholds (around 1 inch/hr in a few areas). Antecedent flash drought has affected some portions of south-central Pennsylvania and western Maryland, suggestive of a slightly lower flash flood risk and higher rain rates needed for potential impacts. Storms are expected to develop/overspread the eastern half of the discussion area (NY through northeastern MD) a bit later in the day (after around 18Z-20Z or so). Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_jgdsv_K_IRgzqYKS5RgxrErvGbX1cMaOPrcArGqqT7BBdHNwtiwQw9rkJbKZnikC8Yu= 5K86nRhY41Expe1X-ScUAUo$ for graphic product... ATTN...WFO...ALY...BGM...CTP...LWX...OKX...PHI... ATTN...RFC...MARFC...NERFC...NWC... LAT...LON 42257416 41217369 40067393 39247478 38777588=20 38887678 39147741 39777793 40597715 41707624=20 42177508=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) .