512 FXUS64 KEWX 191955 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 255 PM CDT Mon May 19 2025 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Tonight through Tuesday night) Issued at 254 PM CDT Mon May 19 2025 Key Message: - Low chances for isolated thunderstorms late this afternoon and evening across the northern Hill Country and portions of the nearby I-35 corridor. Dryline advancement is likely to be slower than previously anticipated and this along with the stronger forcing to our north may limit our convection chances for the remainder of this afternoon and evening. However, any storms that manage to develop will likely be severe with large hail and damaging winds being the main severe weather concerns. The dryline will eventually advance eastward early Tuesday morning as a cold front quickly follows behind. We have kept rain chances out of the forecast Tuesday morning mainly for areas east of the I-35/I-37 corridors as most of the hi-res models do not show much of a signal for convection. We will continue to monitor and may need to add some low rain chances pending model trends. While we will see some very slight cooling across portions of the southern Edwards Plateau, Hill Country into the nearby I-35 corridor, highs will still be well above normal ranging from the lower to mid 90s. It will be hot again elsewhere as compressional warming and downslope flow aid in yielding highs in the upper 90s to near 105 degrees along the Rio Grande. Northerly winds, mostly clear skies and dry air will allow low temperatures Tuesday night to drop into the lower 60s to lower 70s. && .LONG TERM... (Wednesday through Monday) Issued at 254 PM CDT Mon May 19 2025 Key Messages: - Low to medium chances (20 to 40 percent) of isolated showers and storms Thursday, Sunday, and Monday. - Unseasonable warmth continues through the weekend with increasing humidity. The slightly drier and cooler airmass in the wake of Tuesday`s cold front will have only a brief stint over our region as redeveloping zonal flow aloft quickly reestablishes a low-level southerly flow by Wednesday evening, which holds for the remainder of the long term forecast period. Temperatures look to be slightly moderated from the mid May heat wave, but are still forecast to be well above normal values for the time of year with highs in the 90s throughout South Central Texas. Late Wednesday into Thursday, medium range guidance depicts a shortwave tracking across Coahuila into South Texas. This will favor convective development over higher terrain in Mexico, and these could persist into the Rio Grande Plains late Wednesday into early Thursday. Model soundings suggest capping could build in quickly overnight, so rain and thunder chances would depend on the timing of the shortwave... earlier onset of convective activity over the high terrain would be more favorable for those chances, though current placement of the disturbance would primarily limit coverage to our southwestern counties. There remains large spread in shortwave timing in the latest guidance, and PoPs remain limited to the Rio Grande Plains with values less than 20 percent. On Thursday, a slight southward push of high pressure rearward of an outgoing longwave trough under northwesterly flow aloft may push a backdoor cold front over North Texas. As the front encounters the advancing moist Gulf airmass over our region, that could trigger some storms, and storm motion vectors do favor southward progression potentially into our area. While it is somewhat doubtful that the front itself would reach this far south (as the GFS depicts), isolated storms could move off ahead of the front and affect our northern counties, with higher chances (with PoPs up to 30 percent) over the northern Hill Country and northern I-35 corridor later in the day. Some of the guidance suggests potential for a more organized multi-storm cluster, but mesoscale factors are too uncertain at this range. Mid-level ridging becomes well established Friday and throughout Memorial Day weekend. Ambient temperatures are forecast to remain unseasonably warm, with highs in the upper 90s across most of the region and low 100s along the Rio Grande. Gradually increasing moisture thanks to the persistent southerly flow will drive heat indices into the 100 to 105 range, with low temperatures creeping up into the mid 70s over the weekend. An increase in troughing late Sunday into early next week over the western CONUS will promote increased divergence and a strengthening and thickening of the low- level jet over our area. This supports a more stout near-surface moist layer and chances for rain late Sunday into Monday across South Central Texas. As the aforementioned troughing brings southwesterly flow aloft into our area, the stage could be set for a wetter and stormier pattern next week. The Climate Prediction Center notes odds tilted towards above average precipitation for next week throughout Texas. && .AVIATION... (12Z TAFS) Issued at 624 AM CDT Mon May 19 2025 MVFR ceilings have overspread much of South Central Texas with VFR conditions only in the far west including KDRT. Widely scattered thunderstorms have formed over the Rio Grande Plains and are moving northeast over the southern Edwards Plateau and Hill Country this morning. Given their track, have no mention of precipitation at terminals. Southerly wind will become gusty this morning through the afternoon at I-35 sites before decreasing this evening. At KDRT, wind becomes lighter this morning before becoming westerly behind the dryline. Isolated thunderstorms may develop again this afternoon or evening mainly over the Hill Country or northern I-35 corridor, however confidence remains low enough to not mention in the AUS TAF at this time. && .CLIMATE... Issued at 227 PM CDT Sun May 18 2025 RECORD MAX TEMPERATURES MONDAY AND TUESDAY (* TIED RECORD WITH MOST RECENT OCCURRENCE SHOWN) MON TUE 05/19 05/20 ----------------------------- AUS 97/2006 99/2008 ATT 98/2022* 101/2008 SAT 101/1989 100/1996 DRT 108/2020 105/1973 && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 95 73 96 66 / 20 10 0 0 Austin Bergstrom Intl Airport 95 73 97 63 / 20 10 0 0 New Braunfels Muni Airport 97 73 99 66 / 10 10 0 0 Burnet Muni Airport 93 68 92 63 / 40 20 0 0 Del Rio Intl Airport 104 71 100 72 / 20 0 0 0 Georgetown Muni Airport 93 70 92 61 / 20 20 0 0 Hondo Muni Airport 99 70 100 69 / 20 0 0 0 San Marcos Muni Airport 96 73 99 64 / 20 10 0 0 La Grange - Fayette Regional 93 76 97 66 / 10 10 0 0 San Antonio Intl Airport 98 74 100 69 / 10 10 0 0 Stinson Muni Airport 100 75 102 70 / 10 10 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Platt Long-Term...Tran Aviation...Platt
No recent Short Term Forecast (NOW) has been issued for NWS Austin/San Antonio CWA (EWX).
Special Weather Statement Issued: 05/19/2025 06:28:00 PM UTC