textproduct: Austin/San Antonio

KEY MESSAGES

- Overnight rain chances decreasing and will remain mostly low through Friday afternoon.

- Active and unsettled weather pattern continues into late next week. Multiple rounds of storms with heavy rain could lead to localized flooding.

SHORT TERM

(Today through Saturday) Issued at 119 AM CDT Fri May 22 2026

A round of storms that went through San Antonio in the late evening will continue to weaken as it continues east over the Coastal Prairies. Meanwhile a curious new area of convection formed over the Permian Basin and will move over our Edwards Plateau counties early in the morning. This convection contains a lot of lightning and will probably continue for much of the overnight. The 00Z NAM appears to handle this convection well, sending a small weakening complex into the Rio Grande Plains toward daybreak. This outdoes the past few runs of the HRRR which initialized the current convection quite poorly. It does appear that the new 03Z HRRR run coming in starts off better. While the GFS also initialized that storm cluster well, it propagates things more east while the NAM trends make more sense where the atmosphere has not yet been worked over. A few residual showers could carry into daytime, but we would expect most of the daytime PoPs/coverage to be capped at around 30 percent and favored over eastern row of counties.

This relative benign period of weather could thus allow for today to be one of the warmer days of the week, but should still be just shy of normal May afternoon high temperatures. NBM PoP trends continue to show a good signal for another ripple of energy moving into the SW flow aloft for Friday night. The latest deterministic runs show some agreement but also some hesitance to carry into our eastern counties. With a whole day of good warming expected while chances are low, we'll stick to the higher NBM values to avoid forecast inconsistency from run to run. The elevated rain chances are even higher and broader in coverage into daytime Saturday; given the fairly progressive eastward motions of this activity and the flow aloft, it's probable that most areas will only see enhanced chances in one of the Saturday or Saturday night periods. We're hoping the populated QPF is correct for these periods where heaviest rains give the Hill Country and Central TX a break and focus more over our southern counties. As with most of this activity, this next round would also be expected to have the typical large areas of 1 inch with isolated 3-4 inch amounts.

LONG TERM

(Saturday night through Thursday) Issued at 119 AM CDT Fri May 22 2026

Our unsettled weather pattern remains in place through at least next Thursday and potentially into next weekend. If Saturday morning overachieves with the activity that begins late Friday night, then Saturday night and Sunday could be a brief recover period with a downward PoP trend by the time we get there. But the pattern is still unstable and could be also be shifted later on timing. In general the broad flow aloft continues to be unstable southwesterly, as the shortwaves tend to shrink as they enter East TX. This would favor continued every other day rounds of organized convection, with low end chances for severe weather and increasing flood potential with time. There could be relatively stronger solution to promote rain on Memorial day, as there as signs that a weak upper low sits briefly over TX. This could send precip potentials higher for this period, if it comes to pass, but the run-to-run trends are still too irregular to gain any confidence.

AVIATION

(12Z TAFS) Issued at 554 AM CDT Fri May 22 2026

Mid and high level clouds have hampered low cloud development so far this morning. We have adjusted the TAFs to show TEMPO MVFR through 16Z rather than prevailing. VFR is then expected from late morning through the early evening hours. Some afternoon convection remains possible, but given low coverage, we will not mention in the forecast at this time. Low cloud development appears to return to most areas after 23/05Z.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 88 72 84 69 / 20 20 80 60 Austin Bergstrom Intl Airport 88 72 83 68 / 20 20 80 60 New Braunfels Muni Airport 87 70 83 67 / 20 20 80 60 Burnet Muni Airport 84 69 81 66 / 20 20 70 50 Del Rio Intl Airport 91 71 87 68 / 10 20 40 10 Georgetown Muni Airport 86 70 82 67 / 20 20 70 60 Hondo Muni Airport 86 70 82 66 / 10 40 80 50 San Marcos Muni Airport 87 71 83 68 / 20 20 80 60 La Grange - Fayette Regional 87 72 83 69 / 30 20 90 70 San Antonio Intl Airport 87 72 83 68 / 10 30 80 60 Stinson Muni Airport 87 72 83 68 / 10 30 90 60

EWX WATCHES/WARNINGS/ADVISORIES

Flood Watch from this evening through Monday evening for TXZ171>173-186>194-204>209-219>225.