Flash Flood Guidance
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Issued by NWS
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994 AWUS01 KWNH 050213 FFGMPD TXZ000-OKZ000-050800- Mesoscale Precipitation Discussion 0225 NWS Weather Prediction Center College Park MD 1012 PM EDT Sat May 04 2024 Areas affected...west-central to central TX Concerning...Heavy rainfall...Flash flooding likely Valid 050211Z - 050800Z Summary...Flash flooding is likely to continue over portions of west-central into central TX over the next 6 hours. Some significant flash flooding will be possible, especially over central TX, west of I-35 and south of I-20 where an additional 3 to 6+ inches is expected through 08Z. Discussion...0145Z radar imagery over TX showed areas of widespread thunderstorms within a messy distribution of convection and surface boundaries. An MCV was noted over the southeastern TX Panhandle, tracking toward the northeast, parallel to a slow moving cold front which was preceded by a broken region of thunderstorms. In addition, slow moving thunderstorms were noted over central TX, north of a composite outflow boundary that extended from near TPL, west-southwest to just north of 6R6. Instability of 1000 to 2000+ J/kg was in place across TX, supported by steep 700-500 mb lapse rates of 8-9 C/km as sampled by 00Z soundings from DRT, MAF and FWD. Large scale lift ahead of a shortwave trough, tracking east across NM, will continue to overspread a large portion of TX overnight, with highly divergent/diffluent flow aloft setting up over portions of central TX, within the right entrance and left exit regions of associated upper level jet maxima. Precipitable water values have increased into the 1.5 to 1.7 inch range for much of the region ahead of the cold front and southeasterly winds at 850 mb are forecast by the RAP to sustain at roughly 20-30 kt, supporting lift atop rain-cooled air at the surface. Eventual congealing into a more organized MCS is expected through 06Z, but with the longest residence time of heavy rainfall occurring for the region of central TX south of I-20 and west of I-35, where rainfall rates of 2 to 3+ in/hr will be most likely to continue within areas of training and cell mergers. Portions of central TX are more sensitive to flash flooding due to recent rainfall and the addition of another 3 to 6+ inches could lead to areas of significant flash flooding. Farther north, the track of the MCV into southern OK may support a narrow stripe of heavier rainfall near the slow moving frontal boundary. Farther west, across southern portions of the Permian Basin, a supercell tracking into Crockett and Val Verde counties is expected to continue toward the east while convective development, along the southwestern edge of the expected MCS, potentially leads to training for portions of the Hill Country overnight. Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...EWX...FWD...HGX...LUB...MAF...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 34449718 32719622 31439546 30899568 30559655 30299809 30000006 30100142 30370196 31020203 31950107 33110036