Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 05 2025 13:18:05 AWUS01 KWNH 051317 FFGMPD TXZ000-051900- Mesoscale Precipitation Discussion 0596 NWS Weather Prediction Center College Park MD 917 AM EDT Sat Jul 05 2025 Areas affected...Western portion of Texas Triangle...Eastern Hill Country... Concerning...Heavy rainfall...Flash flooding likely Valid 051315Z - 051900Z SUMMARY...Scattered thunderstorms linger on periphery of dying MCS. Highly efficient with rates of 2-3"/hr possible and slow motions will likely continue to pose a flash flooding risk in vicinity. Localized spots of 3-5" DISCUSSION...The dying MCC remains in a mid to upper level col though shearing toward the north into northern TX has been noted, while further elongation appears to be occurring to the south as well. CIRA LPW shows core of deep layer moisture resides in the surface to 850mb layer across the southern and eastern sides of the cyclone, though 850 and aloft the deep layer moisture has shifted toward the central TX coast and due northward. As such, extreme total PWat values up to 2.5" exist in the southeast quadrant of the cyclone in proximity to I-10 in the northern coastal Plain east of Austin. VWP and RAP analysis shows this is the greatest moisture flux with 25-30kts of southerly 850-700mb flow skirting the eastern side and becoming increasingly convergent across the northern Triangle north of Waco toward Cleburne toward the Dallas/Fort Worth Metroplex. Due to the very high theta-E near the surface, even 6C/km lapse rates remain still left of the parcel; narrow skinny/unstable profiles support 1500-2000 J/kg of MLCAPE for any cells to strengthen. As such, low level convergence along the eastern side of the dying MCS has two major clusters along the northeast quadrant and the southeast quadrant. Rates of 2-3"/hr should be common with updrafts, though peak intensity.=20 Aloft, the diffluent portion of the upper-level jet is dropping southward slowly and is currently enhancing convection in the northern Coastal Plain in the southeast quadrant given the 30-40kt exiting jet streak heading south and southwest around the building ridge over W TX. However, weak divergence/diffluence aloft remain modest across northeast TX as well though winds are lighter.=20 However, this slower flow will allow for greater duration as cell motions remain below 5/10kts in the col in the northeast. This may allow for a few hours of compounding totals with focused/localized totals of 3-5" possible, likely to induce additional flash flooding concerns. Hi-Res CAMs help to suggest that storms could move back northwest and west to affect areas most recently affected across the Middle Colorado River, but loss of instability/heating and weak steering flow make this seem more aggressive that observational trends show, however, this reduces confidence toward overall evolution and the area with significant ongoing flooding in the Colorado Basin may have some additional rainfall to further compound flooding concerns in the next 4-6hrs. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Z8ZOY13jdCMEA9w11XTz9fSoNEte1wK9-6FHVz6FeCspRL1vbnBmBnAqr4VwhtNH5lh= GA2HViFt6S8EpIsEV-h3XZM$ for graphic product... ATTN...WFO...EWX...FWD...HGX... ATTN...RFC...FWR...NWC... LAT...LON 32909811 32669708 31899668 30929665 30129672=20 29449704 29029732 28819795 28989854 30499839=20 30969839 32279867=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) .