Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Sep 07 2024 00:58:06 AWUS01 KWNH 070058 FFGMPD ALZ000-MSZ000-LAZ000-070600- Mesoscale Precipitation Discussion 0983 NWS Weather Prediction Center College Park MD 857 PM EDT Fri Sep 06 2024 Areas affected...central Gulf Coast Concerning...Heavy rainfall...Flash flooding possible Valid 070055Z - 070600Z Summary...Localized flash flooding will be possible across portions of the central Gulf Coast, and more specifically, over southeastern LA in the vicinity of Lake Pontchartrain over the next 3-5 hours. Peak rainfall rates of 2 to 3+ in/hr will be possible from slow moving cores of heavy rain.. Discussion...Radar trends over the past 1-2 hours showed a west-east axis of heavier rain over the I-10 corridor transitioning into a mesolow with nearly stationary movement of heavy rain centered over Lake Pontchartrain. The mesolow appears to be located along a quasi-stationary front within a very moist environment containing 2.5 inches of precipitable water, a warm cloud layer depth of 15.7 kft and LFC-EL mean wind of only 3 kt (via 00Z LIX sounding). Despite weak MLCAPE of <500 J/kg on the LIX sounding, sufficient lift within the moist environment has been enough to support MRMS-derived hourly rainfall of 1 to 2+ in/hr through 0030Z. The environment across the central Gulf Coast will remain favorable for the development of slow moving cores of heavy rain as southerly low level flow continues to pump in some of the highest area precipitable water values across the Gulf of Mexico (2.5+ inches) located just south of the central Gulf Coast to a surface low in the western Gulf. The front or elevated frontal boundary could allow for the formation of additional mesolows capable of localized very high rainfall rates. While recent hires guidance does not have a handle on this feature, it seems plausible that a threat area from south-central LA to about Mobile Bay will have the greatest chances of high rainfall rates and localized flash flooding over the next few hours. While any flash flooding is expected to be localized, high rainfall totals may still result with short-term rainfall totals of 3 to 5+ inches. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4BefrbtDW1rYhRTydMXezfIVFHCbtHwjTPFG001DoIY-HfkgvqnKgCpqTyZsNTIlygZP= K1ytDCyVUBOwIDhNnTtJ0RE$ for graphic product... ATTN...WFO...LCH...LIX...MOB... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 30848888 30848831 30728792 30458781 30068789=20 29988858 29838892 29748926 29658971 29619005=20 29599049 29619091 29609134 29989201 30459178=20 30609065 30678988=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) .