


Flash Flood Guidance
Issued by NWS
Issued by NWS
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786 AWUS01 KWNH 041433 FFGMPD TXZ000-042000- Mesoscale Precipitation Discussion 0586 NWS Weather Prediction Center College Park MD 1033 AM EDT Fri Jul 04 2025 Areas affected...Hill Country and Edwards Plateau of south-central Texas... Concerning...Heavy rainfall...Flash flooding likely Valid 041430Z - 042000Z SUMMARY...Slow moving MCC continues to compound significant flash flooding with some areal expansion expected over next few hours. WPC upgrade to Moderate Risk. DISCUSSION...GOES-E WV suite depicts the fairly symmetric MCC remains ideally within anticyclonic wedge; while not very strong outflow is sufficient with impressive transverse banding features along much of the northern hemisphere of the circulation and with the persistent strong updrafts/latent heat release the MCV continues to remain strong near the McCulloch/Saba/Mason county intersection. Regional RADAR mosaic denotes this with impressive arched convective band along the effective cold front within the western quadrant of the MCC from Mason to Sutton county and VWP shows solid warm advective profile off the Rio Grande confluent across central South Texas further expanding effective warm frontal banding like features along and downstream to the SE of the MCV. Upstream well of continued very moist and unstable air with TPW values over 2.25" and MLCAPE gradient of 1000-2000 J/kg along the southwest to southern side of the circulation. This will support cells capable of 2-3"/hr As the MCV wobbles and confluence increases into the WAA, the band will once again shift across the Guadalupe River Valley likely to induce another wave of flash flooding conditions. While Hi-Res CAMs continue to suggest a weakening phase over the next few hours, the upstream inflow and potential for upstream development along the WAA regime may result in relatively with south-southwest propagation equal/stronger than 10-15kt inflow resulting in stationary cells with spots of additional 4-6" possible. As such significant to catastrophic flash flooding is likely to continue with potential to expand along the southern periphery of the MCC. Gallina ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...EWX...SJT... ATTN...RFC...FWR...NWC... LAT...LON 31449905 30979848 30689768 29959762 29429807 29189869 29099927 29310003 29940063 30470084 30860075 31040040 31299992 31429983