Flash Flood Warning 26, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
559 AM CDT Fri Jun 5 2026

...New AVIATION...

.KEY MESSAGES...

- Locally heavy rainfall possible early this morning across the
  Rio Grande plains and southern Edwards Plateau. Scattered
  showers and storms elsewhere, especially during the afternoon
  hours.

- Rain chances continue Saturday but may be impacted by what
  occurs Friday.

- Warmer temperatures early next week, with some low rain chances
  mainly along and east of I-35.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 126 AM CDT Fri Jun 5 2026

Late evening satellite and lightning data shows convection
developing over the higher terrain of Mexico well west of the Rio
Grande. Incoming hi-res models suggest some of this activity will
continue to develop and eventually move into the Rio Grande plains
and southern Edwards Plateau early this morning. Given plenty of
atmospheric moisture, as evidenced by the 1.82" precipitable water
value on the 05/00Z sounding at Del Rio, locally heavy rainfall will
be a concern. While we have not seen a great deal of consistency
among the models regarding the evolution of convection, WPC has
rightfully maintained a Marginal Risk (Level 1 of 4) for excessive
rainfall along the Rio Grande through the early morning hours. Any
outflow boundaries from the morning convection in conjunction with
the arrival of several disturbances and daytime heating should
generate scattered convection farther east across the remainder of
south central Texas this afternoon and early evening. Again, with
plenty of moisture and fairly slow storm movement, a few spots may
pick up some locally heavy rainfall.

The active southwest flow aloft remains intact tonight and while we
could see some additional chances for showers and storm, suspect the
NBM guidance could be a little high on rain chances, especially
after Midnight.

Rain chances on Saturday will likely hinge on what takes place on
Friday and Friday night. Southwest flow aloft remains firmly in
place, but with an upper low over the Permian Basin and south plains
region, most of the more organized lift is expected to largely
remain to our north. The exception could be across portions of the
southern Edwards Plateau where models indicate the upper trough axis
will move through during the peak heating hours.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 126 AM CDT Fri Jun 5 2026

A drying trend is still anticipated for Sunday, with fairly low
chances for rain confined to areas along and east of I-35/I-37. Some
clearing of clouds is anticipated along the Rio Grande into portions
of the Hill Country with partly to mostly cloudy skies elsewhere. We
should start to see temperatures warm on Sunday, but are expected to
remain near or perhaps just below climatological normals.

The subtropical high will build over Texas through the remainder of
the forecast period. This will lead to a mostly dry forecast along
with a slow warming trend. We will need to monitor for some
afternoon showers and storms developing along the sea breeze, but
any rain chances will remain low. Highs will trend upward with 90s
for most locations along with overnight lows in the 70s.

&&

.AVIATION...
(12Z TAFS)
Issued at 550 AM CDT Fri Jun 5 2026

Isolated thunderstorms are moving through San Antonio. This will
continue for another hour or so. Outside of storms ceilings will
be MVFR until late morning. Showers and thunderstorms will develop
again this afternoon and evening. Late tonight low ceilings will
develop again. LIFR is likely in Austin and San Antonio.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  73  87  75 /  50  60  50  40
Austin Bergstrom Intl Airport  86  73  87  75 /  50  60  50  30
New Braunfels Muni Airport     85  71  86  73 /  50  70  40  20
Burnet Muni Airport            83  71  84  72 /  40  50  50  60
Del Rio Intl Airport           85  71  90  75 /  50  30  10  20
Georgetown Muni Airport        85  72  86  73 /  40  50  50  50
Hondo Muni Airport             83  71  86  73 /  50  60  30  30
San Marcos Muni Airport        86  72  87  74 /  50  60  40  20
La Grange - Fayette Regional   86  73  86  75 /  50  50  50  20
San Antonio Intl Airport       84  73  86  75 /  50  70  30  30
Stinson Muni Airport           85  72  87  75 /  50  60  30  20

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...Platt
LONG TERM....Platt
AVIATION...05