Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
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058 FXUS64 KEWX 011120 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 620 AM CDT Wed May 1 2024 ...New AVIATION... .SHORT TERM... (Today through Thursday) Issued at 310 AM CDT Wed May 1 2024 Key Points * Isolated to scattered strong to severe storms this afternoon through tonight * Large (possibly very large greater than >2 inch) hail and damaging winds the main threats * A tornado or two is possible * Locally heavy rainfall and flooding possible A warm and humid airmass remains over South Central Texas early this morning. Several features will provide forcing for showers and thunderstorms of this airmass. These are an approaching mid level shortwave, the dryline in western Texas, the Serranias del Burro of Mexico, and heating. There may be a few showers or patchy drizzle this morning. Then, showers and thunderstorms will develop over parts of our area, as well as along the dryline and over the Serranias del Burro this afternoon. A strengthening moist southerly low level jet and the passage of the shortwave will maintain the showers and thunderstorms this evening through early Thursday with them organizing into clusters while some supercells remain discrete. Forecast soundings show MUCAPE of 3,000 to 4,000 j/kg, mid level lapse rates of near 8 C/km, and 0-6 km shear around 30 kts. This indicates a potential for severe storms. Large, possibly very large hail and damaging winds are the main threats, however a tornado or two is possible. SPC has our area in a marginal to slight (1 and 2 out of 5) risk for severe storms. The greatest risks are for Val Verde County, Edwards Plateau, Hill Country, and Central Texas. Above seasonal normal PWS as high as 2 inches indicate a potential for heavy rains, especially where storms train or possibly stall. These heavy rains would mostly cause urban and small stream type flooding with a few cases of flash flooding possible. WPC has our area in a marginal to moderate (1 to 3 out of 4) risk of excessive rainfall. The greatest risks are from Central Texas to the US 77 corridor. The exit of the shortwave will take the activity east of our area Thursday morning leaving a somewhat stabilized airmass. As a result, expect mainly isolated showers and thunderstorms Thursday afternoon due to heating, the dryline into Val Verde County, and any leftover surface boundaries. Can`t rule out a strong to severe storm or two and locally heavy downpours. Above normal temperatures continue today through Thursday. && .LONG TERM... (Thursday night through Tuesday) Issued at 310 AM CDT Wed May 1 2024 Slight to low end chances for showers and thunderstorms are forecast for the Hill Country and areas along and east of Highway 183 on Thursday night. The shower and thunderstorm activity shifts to the east as the night progresses and a mid level short wave pushes into east Texas. Expect patchy fog to develop overnight and to continue into Friday morning mainly for locations along and east of Interstate 35 corridor. Overnight lows are forecast to range from the upper 60s across the Hill Country to mid 70s across the Rio Grande and Coastal Plains. The patchy fog and even some hazy skies are forecast for Friday morning with a slight chance for showers and storms mainly to the east of Highway 77. Partly cloudy to cloudy skies are expected across South Central Texas on Friday afternoon with highs in the mid 80s across the eastern half of the local area to low and mid 90s across the southern Edwards Plateau and Rio Grande. An active dry- line over west Texas is likely to help with the generation of showers and thunderstorms ahead of the boundary. Those showers and storms are likely to push across the Serranias del Burro Mountains and into the Rio Grande late Friday afternoon into the evening. Can`t rule out a strong storm to move into the Del Rio or vicinity areas and then follows a southeastern track based on mid to upper level flow. This activity could be over by midnight or shortly after. Saturday begins cloudy with some breaks in the clouds by the afternoon. Highs in the 80s across the Hill Country, I-35 corridor and Coastal Plains and low 90s along the Rio Grande. With some instability in place and the passage of an upper level disturbance, expect new shower and storm development across the Rio Grande and southern Edwards Plateau on Saturday afternoon and part of the evening. By Sunday, a stationary front is forecast to be located across Central Texas while the dry-line sits over west Texas. In addition, a pulse of energy in the mid to upper level flow from the southwest is likely moving over Central Texas. The combination of these features bring a low end chance for showers and storms across the Hill Country, southern Edwards Plateau and Rio Grande. Nearby San Antonio areas and locations to the south and east are expected to stay dry. Highs in the 80s most areas with low 90s along the Rio Grande. For the start of the work week, an upper level short wave is forecast to push across the Southern Plains and the active dry-line pushes across Val Verde County. Medium range models keep showers and storms to the north of the local area, however, this could change in future weather packages as we get closer to the weekend. Temperatures are increasing as we move into Tuesday and Wednesday with highs in the mid to upper 90s and up to 100 and 105 range along the Rio Grande. && .AVIATION... (12Z TAFS) Issued at 620 AM CDT Wed May 1 2024 A mix of IFR/MVFR CIGs will lift to VFR this afternoon, then lower back to a mix of IFR/MVFR later this evening through tonight. SHRA/TSRA will develop this afternoon, then continue through this evening out west and through much of tonight in the east. Have maintained PROB30s. Later forecasts may have to update to go prevailing. The SHRA/TSRA may disrupt the lower CIGs tonight for a time. Light to moderate S to SE winds prevail with the possibility of strong wind gusts with the TSRA. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 85 70 84 72 / 60 70 40 20 Austin Bergstrom Intl Airport 84 69 84 71 / 60 70 40 20 New Braunfels Muni Airport 87 71 86 72 / 60 60 20 20 Burnet Muni Airport 82 69 83 70 / 50 70 40 20 Del Rio Intl Airport 89 74 96 75 / 20 30 10 0 Georgetown Muni Airport 84 69 83 70 / 50 80 50 30 Hondo Muni Airport 87 69 85 70 / 50 60 20 10 San Marcos Muni Airport 86 69 85 70 / 60 60 30 20 La Grange - Fayette Regional 86 72 84 72 / 50 60 40 20 San Antonio Intl Airport 85 70 85 72 / 50 60 20 10 Stinson Muni Airport 87 72 86 72 / 60 50 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...04 Long-Term...17 Aviation...04