Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Apr 17 2023 05:08:59 AWUS01 KWNH 170508 FFGMPD FLZ000-171100- Mesoscale Precipitation Discussion 0195 NWS Weather Prediction Center College Park MD 108 AM EDT Mon Apr 17 2023 Areas affected...southeastern Florida Concerning...Heavy rainfall...Flash flooding possible Valid 170507Z - 171100Z Summary...A few areas of heavy rainfall/localized flash flooding remain possible as storms across southwestern Florida and the Keys gradually migrate eastward. Discussion...Despite a relative lull in convective precipitation over southeastern Florida over the past couple hours, a couple of factors for heavy rainfall are located just west of the region currently, including: 1) an MCS over the Keys and vicinity and 2) a couple of mid-level shortwave troughs over the southeastern Gulf (near 27.5N/82.8W and 23.4N/86.8W). These features should move through the region over the next 6 hours and interact favorably with a very moist/buoyant pre-convective airmass characterized by 1.8 inch PW and 1500 J/kg MLCAPE to support renewed, deep convection. Low-level shear profiles are not impressive, and convection over the Keys has tended to be outflow-dominant and forward propagating. It is possible that these trends could keep expected rainfall amounts in the 1-3 inch range through 11Z, although any cell mergers or deceleration of the Keys MCS could result in locally higher totals. The concern with the ongoing flash flood scenario is that heavier rainfall could materialize over areas that have already experienced 3-5 inches of rainfall today near and just south of West Palm Beach - and areas that experienced extreme rain rates and prior impacts near the Fort Lauderdale area on 4/12-4/13.=20 Ground conditions in these areas are more sensitive than usual given the prior rainfall and hydrophobic/urbanized land surfaces. It will not take much additional rainfall to result in renewed or worsened impacts especially if the heaviest of rainfall (1+ inches) materializes in the aforementioned areas. Flash flooding remains a clear possibility in this scenario. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9_5RfLK1ts1i01LQuddGFNTd61rcL817I8J6lRR7EEbXOQeotAVlo388qdR33kyyH6jF= b0q8lxhQ7ZYvQFyGKvGSdo0$ for graphic product... ATTN...WFO...MFL...MLB... ATTN...RFC...SERFC...NWC... LAT...LON 27328023 26668002 25858015 25488034 25468062=20 25768065 26158058 27208061=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) .