Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Feb 16 2023 21:16:59 AWUS01 KWNH 162116 FFGMPD VAZ000-WVZ000-OHZ000-GAZ000-TNZ000-KYZ000-ALZ000-MSZ000-170315- Mesoscale Precipitation Discussion 0069 NWS Weather Prediction Center College Park MD 415 PM EST Thu Feb 16 2023 Areas affected...Portions of the OH Valley and Mid-South Concerning...Heavy rainfall...Flash flooding possible Valid 162115Z - 170315Z SUMMARY...Areas of heavy showers and thunderstorms will continue to traverse portions of the OH Valley and the Mid-South for the remainder of the afternoon and through the evening hours. Additional areas of flash flooding will remain possible from localized areas of cell-training and locally wet antecedent conditions. DISCUSSION...The latest surface analysis shows a cold front advancing east from portions of the lower OH Valley down through the lower MS Valley. This is ahead of a deep layer trough over the Midwest, and low pressure gradually crossing the OH Valley over the next several hours will drive the cold front east through through the Mid-South bringing additional rounds of heavy showers and thunderstorms. A combination of multicell and supercell convection is expected over especially the Mid-South going into the evening hours given a combination of a moderately buoyant boundary layer and strong vertical shear profiles. The latest RAP analysis shows a nose of MUCAPE values reaching 500 to 1000 J/kg across middle TN, with values of 1000 to 1500+ J/kg farther south over northeast MS and northern AL. Farther north up into areas of eastern KY and southwest WV, the instability is much weaker given clouds and ongoing areas of heavy rain, but there is a very modest level of elevated instability here as well. Strong warm air advection continues over the region with presence of a 40 to 50 kt southwest low-level jet ahead of the front, and this will maintain a favorable thermodynamic environment through the balance of the afternoon and into the early evening time frame across the Mid-South for convection. The PWs across the area continue to gradually rise with given the Gulf of Mexico source region, with values generally 1.25 to 1.5 inches per GPS-derived data. This coupled with the available CAPE values over the next few hours should favor some heavy rainfall rates. Some of the more organized convective structures may be capable of producing as much as 1.5 to 2 inches per hour. Hires CAMS do support the idea of there potentially being some occasional instances of cell-training, and this coupled with the heavier rates may result in some localized swaths of excessive totals with some potential for as much as 2 to 4 inches by early this evening. This may result in some instances of flash flooding, and especially over any areas that were impacted earlier with heavy rainfall given increasingly wet antecedent conditions. The more urbanized locations will tend to see the greatest threat for runoff concerns. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!55Gb6FY5TeZcgbB7xmzxM2s2QWMdCZAbu7lOYFSb3IcRqKL0XLzLYFuBX9n3qxtDmZoB= -qFgiyHMsZTTYPQIFjkuuL0$ for graphic product... ATTN...WFO...BMX...FFC...HUN...JAN...JKL...LMK...MEG...MRX... OHX...RLX... ATTN...RFC...LMRFC...OHRFC...SERFC...NWC... LAT...LON 38718161 38438116 37898130 36858298 34918479=20 33778659 33348802 33218903 33628932 34788843=20 36058703 37628461 38468286=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) .