Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Nov 13 2024 16:33:32 AWUS01 KWNH 131633 FFGMPD MSZ000-LAZ000-ARZ000-132130- Mesoscale Precipitation Discussion 1154 NWS Weather Prediction Center College Park MD 1132 AM EST Wed Nov 13 2024 Areas affected...south-central/southeastern LA into southwestern MS Concerning...Heavy rainfall...Flash flooding likely Valid 131630Z - 132130Z SUMMARY...Training and repeating of thunderstorms should maintain at least localized flash flooding from south-central and southeastern LA into southwestern MS. Localized rainfall rates of 2 to 3+ in/hr will remain possible, falling atop locations which received heavy rain in recent days. Additional totals of 2 to 4 inches will be possible (perhaps locally higher) through 22Z, but the coverage of these higher rainfall totals should remain low/spotty. DISCUSSION...Areas of training thunderstorms in and around the Lafayette metro have resulted in numerous reports of 4-6 inches of rain over the past 4-5 hours with hourly rainfall as high as 4 in/hr. Heavy rainfall has been focusing along an inverted trough or weak frontal boundary extending northward from a weak/elongated low located just south of Marsh Island with the coldest cloud tops over southwestern MS into adjacent areas of LA at 16Z. 12Z soundings from LCH and LIX combined with Layered PW Imagery from CIRA showed the bulk of the nearly 2 inch precipitable water values are focused below 700 mb, with a fair amount of dry air in the middle and upper troposphere. Over the next 3-6 hours, the elongated area of low pressure/shear axis across LA is expected to slowly but steadily get pushed east ahead of a large-scale 700-500 mb trough moving east across the central/southern Plains. Surface to 850 mb convergence will shift into the southwestern quadrant of MS and southeastern LA through 21Z where MLCAPE of 500-1500 J/kg is forecast to reside (highest to south) via the latest RAP guidance. Areas of training thunderstorms are expected to continue with 2 to 3+ in/hr rainfall rates at times, overlapping with areas that received heavy rain over the weekend and may remain hydrologically more sensitive to runoff. Farther east, a low level axis of convergence/leading edge of moisture return to the south of an East Coast surface ridge has been producing a few showers and thunderstorms. This area of convection is likely to shift east as well in a mostly progressive fashion, but an isolated threat for short term training could result in urban flooding for the New Orleans metro over the next few hours. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4tLj5AP-59ex4RZwax1shPABq6k0zjoqsPm_gIICJlTSMXmSSdewwAoW9g_QzwMRn-Li= Em8Cr5v2lBAGXPU1O0pzBEM$ for graphic product... ATTN...WFO...JAN...LCH...LIX...MEG... ATTN...RFC...LMRFC...NWC... LAT...LON 33859027 33688989 33368956 32838930 31428951=20 30298983 29499014 29689133 30039181 30799201=20 32179173 33329125 33839080=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) .