Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 24 2023 15:22:45 AWUS01 KWNH 241522 FFGMPD TXZ000-242100- Mesoscale Precipitation Discussion 0047 NWS Weather Prediction Center College Park MD 1022 AM EST Tue Jan 24 2023 Areas affected...Mid to Upper Texas Coastal Plain... Concerning...Heavy rainfall...Flash flooding possible Valid 241520Z - 242100Z SUMMARY...Increasing convective development and potential for slow moving, efficient rainfall producing cells. Downstream development along warm front may also allow for some repeating and therefore localized flash flooding may be possible with 2-4" totals in short (1-3hrs) duration. DISCUSSION...GOES-E WV depicts a strong compact closed low over the Western TX panhandle pressing eastward with broad favorable diffluent upper level jet pattern with dual right entrance/left exit jet structure out of N TX/OK and across northeast Mexico into far south TX. This is providing a dynamic surface cyclogenesis across central TX this morning with strong emergence of western Gulf higher moist/unstable air pressing a warm front northward from west of COT near the low to BEA to south of VCT and DVY. Low 70s T with mid to upper 60s Tds are supporting increasing unstable air, but given the approaching height-falls the western Gulf LLJ has strengthened to over 50kts per CRP/EWX VWP overriding the frontal zone. WV suite denotes the edge of the best height-falls tightening on the western side of the jet likely to increase deep layer moisture convergence to support growing vertical nature to the showers in the area. Given the strength of flux convergence and increasing MUCAPE values of 1000-1500 J/kg, rainfall efficiency should support intense rates with 1.5" toward 16-17z increasing slowly to about 2" as the cells/convergence move eastward into the core of the moisture axis denoted by TPW of 1.6-1.7". Cell motions will be more north-northwest in the line with slow eastward propagation allowing for some increased duration with quick 1.5-2.5" in a hour and spots of 2-4" possible over 2-3hrs mainly near the warm front near the I-10 corridor east of San Antonio. Intensity of rates will decrease toward the north as isentropic ascent becomes more elevated. Further east, strong surface convergence and slow northward movement of the warm front should allow for scattered cells with isolated more intense rain-rates. Individually they are less likely to induce rainfall rates/totals to induce flooding concerns, with exception in urban locales. However, 1-2" totals with these scattered cells will prime the soils ahead of the main line as it progresses eastward. The intersection/repeat nature will support the greatest risk of rainfall over 3-4" as supported by a bulk of the hi-res CAM guidance providing some confidence.=20 However, there are some guidance solutions as great at 5-6" with the FV3CAM and Candian Regional and while this is not favored, ideal setup/training may allow for this much lower potential given the strong dynamics, warm front placement to the Gulf to at least mention the very low end possibility of it to occur. If it were to manifest, it would very likely be south of I-10 and east toward Galveston Bay given the nature of convection training and reinforcing and locking the frontal zone in place for a longer duration. Soil conditions are quite dry for the area both in depth and relative to the seasonal average, given the intensity of the rates this may actually reduce infiltration with increased run-off, but more likely the vast majority of the area should absorb better than run-off. Given the rates, totals of 2-4" locally higher, flash flooding is considered possible through the late morning into the afternoon. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7Y4aenU4knzwWloMXaLSD4X56sXwXpHHTf5y4xaawbDWt_ijhAEQZjgEecqTZfqi9rt5= Vin0oiUif_0DD-LszUXCDoQ$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX... ATTN...RFC...WGRFC...NWC... LAT...LON 31189646 31069539 30409470 29839474 29319539=20 28889633 28589727 28499766 28419829 28849839=20 29709810 30389767=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) .