Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Nov 20 2022 16:48:57 AWUS01 KWNH 201648 FFGMPD FLZ000-202220- Mesoscale Precipitation Discussion 1126...Corrected NWS Weather Prediction Center College Park MD 1148 AM EST Sun Nov 20 2022 Corrected for label Areas affected...southeastern Florida Concerning...Heavy rainfall...Flash flooding possible Valid 201620Z - 202220Z Summary...An isolated flash flood risk will continue across areas in/near Miami metro through 22Z. Discussion...Scattered showers and isolated thunderstorms continue to move very slowly along coastal areas of southeastern Florida and adjacent areas just offshore. Recent radar/satellite indicates that the heaviest of rainfall was located over Biscayne Bay and confined to areas of somewhat greater, surface-based buoyancy compared to inland areas. The slow storm movement and high moisture content (2+ in PW values) were contributing to areas of 1-3 inch/hr rainfall rates. Meanwhile, low-level flow continues to have a substantial easterly component, allowing for convection to gradually move westward toward the coast and spread rainfall across the Miami-Dade metro area. Rainfall rates in the urbanized areas have stayed generally less than 1 inch/hr though modest MRMS Flash responses have been noted from near Miami southwestward to near Kendall over the past few hours. Convective trends suggest conditional potential for heavier rainfall to eventually migrate inland toward the more populated and sensitive urban areas especially beginning in the next hour or so. A key limiting factor for deeper convection persisting inland remains instability, although easterly low-level flow may help advect some of the more buoyant air inland through the afternoon.=20 Local convective/cold pool influences are also likely to influence longevity of heavier rainfall. Models (particularly the 12Z HREF) also point to heavier rainfall migrating closer to inland areas through 22Z or so, which lines up well with current convective trends. It appears possible that at least a localized flash flood risk could materialize in the Miami-Dade Metro area in the 17-22Z timeframe as persistent, heavier rain rates manage to drift inland. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!88gkbo4gvlHyGV7vqdHcvd_lOWsJBAotKUcC8Knv-X50COIpfQMOlDWuUr1kMRT_NyAH= 1vU9etiUq1epanNsCXnRDJ4$ for graphic product... ATTN...WFO...KEY...MFL... ATTN...RFC...SERFC...NWC... LAT...LON 26938021 26647988 25478009 25238039 25578078=20 26328078 26718049=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) .