Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 23 2023 19:00:25 AWUS01 KWNH 231900 FFGMPD NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-240058- Mesoscale Precipitation Discussion 0572 NWS Weather Prediction Center College Park MD 259 PM EDT Fri Jun 23 2023 Areas affected...eastern Virginia northward to southeastern Pennsylvania Concerning...Heavy rainfall...Flash flooding possible Valid 231858Z - 240058Z Summary...A few areas of training convective have materialized over the past 30 minutes, with 2 inch/hr rain rates noted per MRMS. Flash flooding is possible with this activity. Discussion...Gradually deepening convection has begun to focus along an axis extending from near Philadelphia, PA to near Richmond, VA over the past 30-45 minutes. The storms are in a very weakly forced environment, although lift/ascent associated with a weak cold front/surface boundary appears to be the primary driving mechanism for the linear organization. Instability/shear profiles support efficient rainfall processes from individual cores due to 1.9 inch PW values and areas of 1000 J/kg MLCAPE.=20 Additionally, steering flow aloft was south-southwesterly and parallel to the initiating surface boundary, allowing for training and local areas of 2 inch/hr rain rates. These rates were exceeding FFG thresholds locally that range from 1-2 inches/hr (lowest in eastern VA and across urbanized areas). Ongoing convective trends should continue as we move through peak heating hours. Synoptic features are not expected to change much over the next 3-6 hours, and while the modest increase of linear organization could result in local propagation, instability profiles do not support broad, larger scale propagation that would 1) move convection quickly off it's current axis of heavier rainfall and 2) result in faster storm motions and more limited hourly rainfall potential. As a result, flash flooding should remain possible this afternoon - especially in more urbanized and flood-prone areas. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6DjyC7doNZVIyV2Dr3HKWhQMufF0GOUkmkBX4JDfe3vCM3SXM9M4tb2hp4m_fXNu2EMT= mj67TZAS-lUHp2PK6SEFRNs$ for graphic product... ATTN...WFO...AKQ...CTP...LWX...PHI... ATTN...RFC...MARFC...SERFC...NWC... LAT...LON 40137521 40087467 39727464 38887504 37067606=20 36707611 36787735 37167784 38717709 39217684=20 39977595=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .