Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 03 2024 21:16:33 AWUS01 KWNH 032116 FFGMPD MAZ000-RIZ000-CTZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-04031= 5- Mesoscale Precipitation Discussion 0795 NWS Weather Prediction Center College Park MD 515 PM EDT Sat Aug 03 2024 Areas affected...Portions of the Central Mid-Atlantic up into Southern New England Concerning...Heavy rainfall...Flash flooding likely Valid 032115Z - 040315Z SUMMARY...Heavy showers and thunderstorms are expected well into the evening hours across portions of the central and northern Mid-Atlantic region into parts of southern New England. Some cell-training concerns coupled with high rainfall rates will likely result in scattered to locally numerous areas of flash flooding going into the evening hours. Some locally significant urban flash flooding will be possible along the I-95 corridor. DISCUSSION...GOES-E IR satellite imagery in conjunction with dual-pol radar shows multiple broken bands of well-organized shower and thunderstorm activity traversing the interior of the Mid-Atlantic and some adjacent areas of southeast NY and southern New England. This encompasses a large area focused on northern VA through central MD, and then up across much of eastern PA, northern NJ, southeast NY and southwest CT. The activity continues to organize within a very moist and unstable environment east of the Appalachians and in close proximity to a quasi-stationary front with multiple areas of low pressure lifting northeast up along it. Meanwhile, there is a rather elongated, but fairly sharp mid-level trough advancing slowly into the central Appalachians. MLCAPE values along and east of this front are on the order of 1500 to 2500 J/kg, with even greater magnitudes closer to 3000 J/kg down closer to the Chesapeake Bay and Delmarva region. Meanwhile, PWs are rather high and close to 2 inches. Multiple convergence zones are seen in local observations from near Washington D.C up through central to northeast MD and across southeast PA and northern NJ in connection to multiple outflow boundaries and pre-frontal troughs/mesoscale boundaries. All of this coupled with at least modest ascent/shear ahead of the central Appalachians trough and plentiful instability over the coastal plain should favor multiple bands of heavy showers and thunderstorms evolving well into the evening hours. This will include areas of southeast NY and adjacent areas of southern New England where the convective threat will be influenced by proximity of the aforementioned frontal zone and surface low activity. Expecting rainfall rates with the bands of convection this evening to reach as high as 2 to 3 inches/hour with the stronger cells, and given the threat for some cell-training or at least multiple rounds of heavy rainfall, some storm totals of 3 to 5 inches cannot be ruled out locally. Scattered to locally numerous areas of flash flooding are likely and the I-95 corridor from Washington D.C up through Philadelphia, New York City, and New Haven will need to closely monitor these storms as there are concerns for locally significant urban flash flooding this evening. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5-HYFCPJcxNEXHgs3TJKaiKx68sv-TGCH6k8Vgcp6_Bshg_v4GsJS5VUv6NFcBy5Syfn= 1Iy-48KrGer2E1XMHwh12RU$ for graphic product... ATTN...WFO...AKQ...ALY...BGM...BOX...CTP...LWX...OKX...PHI... ATTN...RFC...MARFC...NERFC...NWC... LAT...LON 42057236 41937148 41467139 40927244 40327357=20 39577424 38407578 38317707 38627751 39057755=20 39407697 40187597 41187504 41807402=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) .