Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 02 2024 08:15:09 AWUS01 KWNH 020815 FFGMPD LAZ000-TXZ000-021413- Mesoscale Precipitation Discussion 0208 NWS Weather Prediction Center College Park MD 414 AM EDT Thu May 02 2024 Areas affected...central into southeast Texas, portions of southwestern/central Louisiana Concerning...Heavy rainfall...Flash flooding likely Valid 020813Z - 021413Z Summary...Complicated convective scenario will continue to pose a potentially significant flash flood risk through 14Z this morning. Discussion...The ongoing convective scenario is described by a couple of prominent linear segments - one about 50 miles NNE of Houston Metro and a second between Austin and Temple. Weaker convection persists between these two dominant linear segments, although the Austin/Temple complex has shown a weakening trend over the past hour - likely due to low-level trajectories from rain-cooled air over east-central Texas. The pre-convective environment (away from any outflow or ongoing convection) remains very moist (2 inch PW values) and unstable (~2000 J/kg MLCAPE), with strong southerly 850mb flow perpendicular to subtle outflows in vicinity of the convection to support occasional backbuilding/training. The complex has exhibited periods of both slow/nearly stationary and fast forward movement at times, enabling periods of 2-4 inch/hr rain rates and 5-9 inch storm totals across portions of the discussion area. Significant impacts have also been noted at times. The ongoing, complicated forecast scenario poses substantial uncertainty over the next 6 hours. Current thinking is that the ongoing linear complex northeast of Houston will maintain its intensity while moving east-northeastward toward southwestern Louisiana parishes through the morning. Continued backbuilding will occur between this MCS and an upstream MCV (centered near ACT/Waco) and continue to spread heavy rain and at least 1 inch/hr rain rates across water-logged areas that experienced 2-7 inches of rainfall earlier. These cells appear to be slightly elevated, which may be hindering intensity/rain rates in the short term. One key uncertainty regarding the ongoing scenario is whether convection can deepen near/south of US 290 between Austin and Houston, where better surface-based instability resides.=20 Surface-based development in this region could result in upscale growth of another linear complex with training characteristics that promote both 1) 2-4 inch/hr rain rates at times while 2) potentially affecting more populated areas closer to Houston Metro. Although uncertain, a significant flash flood episode would be likely - especially if the the scenario depicted by the 06Z HRRR run were to materialize. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5gp5NIzagL_SjrOjOpSlIBPvHpiC5uehdbGbhEE_v1t-tZZv0QssWHamXFKRAH7Ih6FF= tAlsWaODveseEU1AWdMnXgE$ for graphic product... ATTN...WFO...EWX...FWD...HGX...LCH...SHV... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 32059373 31789276 31299209 30429200 29829265=20 29609512 29389661 30059761 30809806 31599753=20 31729677 31719584 31819500 32039443=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) .