Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 12 2024 09:36:07 AWUS01 KWNH 120936 FFGMPD DEZ000-MDZ000-VAZ000-NCZ000-SCZ000-121534- Mesoscale Precipitation Discussion 0609 NWS Weather Prediction Center College Park MD 535 AM EDT Fri Jul 12 2024 Areas affected...portions of the Carolinas and Mid-Atlantic Concerning...Heavy rainfall...Flash flooding possible Valid 120934Z - 121534Z Summary...Scattered heavy downpours are likely to traverse the discussion area from southeast to northwest for most of the morning. Brief heavy rainfall (with rates exceeding 2 inches/hr) could cause a few spots of flash flooding over time. Discussion...The combination of low-level warm/moist advection across the discussion area, an upslope component to that flow, and weakness in geopotential height fields aloft along the East Coast has fostered scattered shower and thunderstorm development across the discussion area this morning. The warm advection regime has maintained an abundantly moist, unstable airmass (characterized by 2.3 inch PW values and 1000-1500 J/kg MLCAPE) to support efficient rainfall rates. Slow northwestward movement of cells within the warm advection regime has supported areas of 1-2.5 inch/hr rain rates at times on an isolated basis. These rain rates were materializing over areas of relatively high FFG thresholds in most areas (2-2.5 inch/hr), although localized spots and urban areas (i.e., Norfolk/Richmond through northeastern NC and the Piedmont) have locally lower FFGs around 1 inch/hr that have supported a locally higher flash flood threat. The ongoing scenario is likely to continue through the mid-morning hours as deep southeasterly flow supports additional heavy rainfall. Models depict an uptick in convective coverage after sunrise, which isn't surprising given the already unstable and uncapped airmass in place. Areas of 2-3 inch/hr rain rates are likely to materialize on at least an isolated basis, which could result in flash flooding especially across aforementioned sensitive areas. Although uncertain, there is some concern for development of a more focused axis of localized banding or training of cells. The greatest risk of this development will exist across southeastern Virginia into eastern North Carolina - especially after 12-13Z or so.=20 Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9_S4DJ7NHqi3x-y2NHlYhxc-d3B9mA-V63Wy5ZF_VeRC9x-g1asy6xSteDlG5ltnR47Y= IuLEDvskJrUm2JD7ImZ4Tds$ for graphic product... ATTN...WFO...AKQ...CAE...GSP...ILM...LWX...MHX...PHI...RAH... RNK... ATTN...RFC...MARFC...SERFC...NWC... LAT...LON 38777555 38337517 36887575 35787560 35297578=20 34527732 33897825 34618026 35228055 36347996=20 38327782 38757644=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) .