Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 12 2023 21:31:13 AWUS01 KWNH 122131 FFGMPD FLZ000-130200- Mesoscale Precipitation Discussion 0179 NWS Weather Prediction Center College Park MD 530 PM EDT Wed Apr 12 2023 Areas affected...South Florida Concerning...Heavy rainfall...Flash flooding likely Valid 122130Z - 130200Z SUMMARY...Additional rounds of thunderstorms in the heavily urbanized corridor of South Florida, where 2-6" of rainfall have fallen since this morning, is susceptible to additional flash flooding through the evening rush hour. DISCUSSION...Doppler radar continues to detect areas of organized convection from Homestead on north to the Fort Lauderdale area. Surface observations as of 21Z show winds shifting from the ENE to the SE between Key Largo and Miami, indicating the warm front is continuing its steady progression north through South Florida. SPC mesoanalysis shows MLCAPE between 750-1,500 J/kg and PWs between 1.8-1.9" available for areas of convection. Latest 20Z RAP also shows a highly saturated profile (>90% RH at low-mid levels), a classic skinny CAPE profile, warm cloud layer depths of 11,000 kft, and effective bulk wind shear values >30 knots. These parameters indicate organized convection along the warm front will be continue to maintain efficient warm rain processes for at least a few more hours. Since 8AM this morning, portions of Miami-Dade and Broward counties have received anywhere from 2-6" of rainfall. These counties remain out ahead of the approaching warm front and given the parameters listed above, the combination of the Miami-Fort Lauderdale metro areas recent rainfall and high concentration of hydrophobic surfaces make them quite vulnerable to additional flash flooding. The warm front will progress faster to the north later this evening and drier/warmer air within the 700-300mb layer will lead to diminishing convection. This could, however, then place the ongoing area of active convection closer to Boca Raton and West Palm Beach, where they also dealt with bouts of rainfall earlier today. This will give the Miami a much needed break, but not before a few more hours of thunderstorms that should produce additional flash flooding through 02Z. Mullinax ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5vkvsIp1beGAA2EpNM4b1qxEBLVL7aXmUUzRG93BUsrRI1cqE3LAsIH2udE9fUOIrhmn= FUPRD2AvZamTsY7rvEQxDWA$ for graphic product... ATTN...WFO...MFL...MLB... ATTN...RFC...SERFC...NWC... LAT...LON 27168056 27138010 26317999 25468023 25488058=20 26118067 26628068=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) .