Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jul 06 2023 08:38:42 AWUS01 KWNH 060838 FFGMPD TXZ000-OKZ000-KSZ000-061330- Mesoscale Precipitation Discussion 0644 NWS Weather Prediction Center College Park MD 437 AM EDT Thu Jul 06 2023 Areas affected...Southern Kansas, Oklahoma, Texas Panhandle Concerning...Heavy rainfall...Flash flooding likely Valid 060836Z - 061330Z Summary...Showers and thunderstorms rapidly developing north of a cold front will expand and intensify through the morning. Rainfall rates at times may reach 3"/hr. The combination of leading slow moving storms and a following MCS may yield 2-4 inches of rain with locally higher amounts. Flash flooding is likely. Discussion...The regional radar mosaic early this morning shows rapidly expanding coverage of showers and thunderstorms across Oklahoma ahead of a potent MCS and developing MCV dropping southeast out of Kansas. This convection is blossoming due to ascent within a region of thickness diffluence downstream of a mid-level shortwave, which is also driving subtle backing of the 20-25kt LLJ to enhance isentropic upglide atop a surface cold front. This lift is occurring within favorable thermodynamics characterized by PWs as high as 2 inches as measured by GPS, overlapped with a ribbon of SPC RAP analyzed MUCAPE in excess of 2000 J/kg. The LLJ rising above the front is directly intersecting the most favorable thermodynamics, resulting in the rapid expansion of convection noted in the last hour. Rainfall rates within this fresh development have been estimated via KVNX to be 1-1.5"/hr, with even greater rain rates estimated within the MCS moving into the OK Panhandle. Although the high-res models are struggling with the exact timing and evolution of development tonight, both ARWs and recent HRRR runs indicate storms downstream of the MCS will persist until this complex sweeps through later this morning. Convection that develops within the WAA/isentropic upglide will move very slowly on 0-6km mean winds of just 5 kts, while anti-parallel Corfidi vectors of just 5-10 kts indicate that backbuilding into the greater instability along the front is likely. With rainfall rates progged by the HREF to exceed 2"/hr, and HRRR 15-min rainfall possibly reaching above 1" in some places, these slow storms could quickly overwhelm soils to produce runoff. Additionally, these slow moving storms will help prime the soils before the MCS sweeps through during the early morning with additional intense rain rates of 2-3"/hr. While this MCS will likely be progressive as it continues its upscale growth, where it moves across areas that also receive the preceding slow-moving convection, total rainfall could reach 2-4", with some local amounts above 5" possible as reflected by recent HREF probabilities. 7-day rainfall according to AHPS has been generally below normal across much of OK, although pockets of 150-300% do exist. This generally has kept streamflow anomalies around normal to slightly below normal and FFG 2-2.5"/3hrs. While this will have at least a somewhat limiting effect on the flash flood potential, these intense rain rates still suggest that flash flooding is likely through the morning, especially in more urban areas, or where the leading slow moving storms can lengthen rainfall duration. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9RyVgBsxqGIZb7TI2BrEQp_yF6MVbknZZ4RBW9bOiiWzPM009Ie45TPA2H_E0pzpMDxu= hPL4zF2zNfEtlvCcJVSLF7Y$ for graphic product... ATTN...WFO...AMA...DDC...ICT...OUN...TSA... ATTN...RFC...ABRFC...NWC... LAT...LON 37969860 37619745 37129634 36399520 35769483=20 35309499 34669539 34139587 34129640 34439742=20 34849829 35269937 35650046 36100146 36510173=20 37060172 37410134 37850033=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) .