Flash Flood Warning 99, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
610 AM CDT Sat Jul 18 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 600 AM CDT Sat Jul 18 2026

- Remaining flood waters continue to move downstream in the
  Nueces, Frio, San Antonio, Llano, and Rio Grande basins. Avoid
  flooded areas.

- Hot July heat and humidity resumes

&&

.SHORT TERM...
(Today through Sunday)
Issued at 1228 AM CDT Sat Jul 18 2026

While the heavy rain and flash flooding threat has come to a close
for South Central Texas, rises will continue to move downstream
many of the region's swollen rivers, including Cibolo Creek, Llano
River, Nueces River, Frio River, and the Pecos River into the Rio
Grande. Some impacts from elevated rises will be seen into early
next week for some riverine areas as flood waters gradually
disperse or spread across floodplains. Avoid flooded areas and do
not drive through flooded roads.

The mid-level shear axis that has been causing us the trouble over
much of the past week has drifted to the northwest. While it will
linger across the Texas panhandle and West Texas region, it will
gradually erode as mid-level ridging builds in from the north. The
Pandale to Langtry area in far western rural Val Verde County may
see a brief light shower with lingering low-level moisture,
otherwise the rest of the region is expected to remain rain free
with some leftover passing high clouds on Saturday afternoon and a
mostly sunny afternoon on Sundays. Highs top out from the mid to
upper 80s in the Southern Edwards Plateau into the low to mid 90s
elsewhere. The standing water and near surface soil moistures with
the recent rain, mixing out of dew points will be tougher and it
will keep heat indices elevated. However, these values look to
remain below the heat advisory criteria. Warm and humid overnights
trend with the development low stratus late overnight into each
morning.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 1228 AM CDT Sat Jul 18 2026

A hot and dry weather pattern is expected to remain through next
week as mid-level ridging continues to gradually amplify and build
southward into North-Central Texas. This will allow for daytime
highs to inch upwards slightly. We'll have to closely monitor the
dew points given the antecedent ground moisture from the recent
rains and flood event, as models could be overdoing the diurnal
mixing of dew points. This would influence how high peak heat
indices could become, but conditions at this time still look to
remain below heat advisory criteria. Otherwise, skies trend partly
cloudy to mostly sunny with no rain expected outside from a very
stray sea breeze shower in the coastal plains late in the week.

&&

.AVIATION...
(12Z TAFS)
Issued at 600 AM CDT Sat Jul 18 2026

MVFR cigs are forecast for the I-35 sites to about 15Z and 16Z
Saturday. VFR cigs return after that period and remain through at
least late Saturday night. For KDRT, MVFR cigs are forecast by
daybreak and stay that way for several hours before lifting to VFR
mid to late Saturday morning. Southerly winds of 10 to 14 knots
are forecast to prevail for most of the next 24 to 30 hours
period. Wind gusts could be between 17 and 22 knots at times
especially during the afternoon. MVFR cigs return to the I-35
sites early Sunday morning around 07Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              95  75  96  75 /   0   0   0   0
Austin Bergstrom Intl Airport  94  75  95  74 /   0   0   0   0
New Braunfels Muni Airport     94  74  96  73 /   0   0   0   0
Burnet Muni Airport            92  73  94  72 /   0   0   0   0
Del Rio Intl Airport           90  75  92  76 /  10   0   0   0
Georgetown Muni Airport        93  75  94  74 /   0   0   0   0
Hondo Muni Airport             92  74  95  72 /   0   0   0   0
San Marcos Muni Airport        94  74  95  73 /   0   0   0   0
La Grange - Fayette Regional   95  75  96  74 /   0   0   0   0
San Antonio Intl Airport       93  75  95  74 /   0   0   0   0
Stinson Muni Airport           94  76  96  74 /   0   0   0   0

&&

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

SHORT TERM...62
LONG TERM....62
AVIATION...17