Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 12 2023 20:13:31 AWUS01 KWNH 122013 FFGMPD TXZ000-OKZ000-130012- Mesoscale Precipitation Discussion 0276 NWS Weather Prediction Center College Park MD 413 PM EDT Fri May 12 2023 Areas affected...west Texas into central Oklahoma Concerning...Heavy rainfall...Flash flooding possible Valid 122012Z - 130012Z Summary...Over time, slow-moving storms are expected to expand in coverage while focusing along surface boundaries in the discussion area. Locally heavy rain rates could cause flash flooding especially in sensitive areas, although this risk is expected to be isolated in the short term. Discussion...Recent satellite imagery indicates deepening cumulus along and just ahead of a cold front and outflow boundary extending from southwestern Oklahoma (near CHK) to west Texas (near MAF). The environment just ahead of this boundary was characterized by strong buoyancy (2500-4000 J/kg MLCAPE) and minimal instability - highest where dewpoints were in the 70s F.=20 Meanwhile, inhibition was minimal and eroding due to continued insolation and subtle ascent from a couple of shortwave troughs centered over west Texas. Models/CAMs and observations suggest that over the next couple hours, convection will expand in coverage and intensity while focusing along the aforemented boundaries. Weak wind fields aloft are likely to promote relatively slow storm motions (15-25 knots), but are also oriented roughly parallel to the initiating boundary to favor localized training. Although weak low-level shear should initially promote outflow-dominant (and locally propagating) convection, the potential for localized areas of 1-2 inch/hr rain rates due to training and slow storm motions should gradually increase through the afternoon and early evening. Convective evolution beyond 22Z is a bit uncertain. Current indications are that maturing cold pools will allow for upscale growth and increased propagation over time. This upscale growth is also likely to occur in tandem with increasing low-level flow and shear, promoting further organization and slow storm movement to promote additional flash flood potential. This scenario will be monitored for additional MPDs over the course of the evening. Lastly, FFG thresholds are low in spots and generally range from as high as 4 inch/hr thresholds west of Midland to 1.5-2 inch/hr thresholds across western north Texas and southwestern Oklahoma.=20 Thus, the flash flood risk will be highest where heavier rain rates can materialize in areas of lowered FFGs and/or urbanized/low-lying areas. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9OwkDSnMZmpfBogWGIht_f3GGx_9d5zjI-bDJk3T4kuWGZEdwI55vlzfWbS7Ad9f0LXG= 3JJ0JF48rg-vPczEV0lBkK0$ for graphic product... ATTN...WFO...FWD...LUB...MAF...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 35669742 35239703 33929740 32199903 31550097=20 31350213 32120259 32890230 33400125 34179977=20 35239859=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) .