FXUS64 KEWX 191818 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 118 PM CDT Tue Aug 19 2025 .KEY MESSAGES... - Active weather with multiple chances for showers/storms expected this afternoon/evening through early next week - Potential for isolated flash flooding from slow moving storms this afternoon through at least Friday && .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... Latest Storm Prediction Center Mesoscale Analysis (17Z) shows an upper level ridge over the four corners region and an upper level inverted trough (likely an MCV) moving over the eastern Texas coast. Area Doppler radars have been detecting moderate to heavy showers across the coastal plains including parts of Lee to Gonzales to DeWitt counties late this morning. This trend is forecast to continue for the rest of the afternoon through mid evening as the upper level inverted trough moves westward. The combination of precipitable water values around 2.0 to 2.4 inches, sea breeze convergence, and the passage of the inverted trough/MCV is likely to result in episodes of heavy downpours over parts of the Hill Country, I-35 corridor, and coastal plains areas. One to two inches of rainfall can't be ruled out over some of these areas with isolated up to three inches if showers/storms slowly track over same locations. The Weather Prediction Center (WPC) updated Excessive Rainfall Outlook (ERO) Day One now highlights parts of the Hill Country, I-35 corridor, and coastal plains under a marginal risk (level 1 of 4) of rainfall exceeding flash flood guidance. With the loss of daytime heating and the MCV pushing to the southwest this evening into the overnight period, rain chances transfer into parts of the the Rio Grande. Rainfall amounts over these areas could range from a trace to one quarter inch. By Wednesday, the upper level ridge over the four corners region remains there while an upper level trough axis pushes over north Texas tracking to the south. Also, today's MCV is forecast to linger across northeast Mexico/Rio Grande area to add instability to the local area for rounds of moderate to heavy showers across most locations of south central Texas. WPC ERO Day Two highlights marginal risk (level 1 of 4) of rainfall exceeding flash flood guidance for most of the local area with the exception of the southern part of the Rio Grande. Rainfall amounts of 1 to 2 inches are possible with isolated 3 inches over some spots. && .LONG TERM (THURSDAY THROUGH MONDAY NIGHT)... The wet and stormy weather pattern continues on Thursday as a frontal boundary pushes into our area with plenty of moisture in place. Rounds of moderate to heavy showers are possible over most locations of south central Texas mainly during the afternoon and evening periods. The frontal boundary could linger around the coastal plains on Friday for more moderate to heavy showers especially for parts of the I-35 corridor and coastal plains locations. the weekend looks a bit drier, however, rounds of showers and storms are possible each afternoon and early evening periods. Highs temperatures are likely to be slightly above average on Wednesday and Thursday and around average on Friday into the weekend. Overnight lows remain in the 70s. && .AVIATION (18Z TUESDAY THROUGH THURSDAY)... VFR conditions are expected outside of any reductions this afternoon and evening with thunderstorm activity. The greatest chances for thunderstorms remain at SAT/SSF westward including over the Hill Country, southern Edwards Plateau and Rio Grande Plains. Around DRT and AUS, PROB30 groups are still warranted with more isolated storm activity expected near those locations. Some wind gusts in excess of 30KT are possible in and near TSRA activity, otherwise wind will mainly be below 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 77 100 76 97 / 10 40 40 50 Austin Bergstrom Intl Airport 76 100 76 97 / 10 40 40 60 New Braunfels Muni Airport 73 99 74 97 / 20 30 30 60 Burnet Muni Airport 75 96 74 94 / 10 40 40 50 Del Rio Intl Airport 77 101 78 98 / 30 20 30 40 Georgetown Muni Airport 76 99 75 97 / 10 40 40 50 Hondo Muni Airport 72 99 75 96 / 30 20 20 60 San Marcos Muni Airport 73 101 74 97 / 10 30 30 60 La Grange - Fayette Regional 74 98 75 94 / 10 40 40 70 San Antonio Intl Airport 76 99 78 97 / 20 30 30 60 Stinson Muni Airport 76 101 78 98 / 20 20 30 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...17 Long-Term...17 Aviation...27