River Flood Warning 44, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1242 AM CDT Fri Jul 17 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 1226 AM CDT Fri Jul 17 2026

- Periods of locally heavy rainfall and the compounding effects
  from multiple rounds of storms the past couple of days is likely
  to result in a continued flash flood threat through at least
  Friday morning, particularly over the western Hill Country,
  southern Edwards Plateau and portions of the Rio Grande Plains.

- Up to considerable flash flood impacts remain ongoing at least
  through the end of this latest round of rainfall

- Up to Moderate to major flooding are ongoing/forecast for the
  Pedernales, Frio, Medina, Guadalupe, San Antonio, and Nueces
  River Basins.

- Heed instructions from local officials and be prepared to
  seek higher ground if necessary.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 1226 AM CDT Fri Jul 17 2026

Latest multi-radar multi-sensor presentation shows light to moderate
rain with isolated to scattered pockets of heavy rain mainly
associated with thunderstorms. This trend is forecast to continue
tonight with an uptick overnight through Friday morning. The low
level jet is increasing with precipitable water coming in at 1.99
inches from the 00Z (Friday) Del Rio sounding and the SPC
mesoanalysis as of 03Z Friday, shows precipitable water values
ranging from 2 to 2.2 inches over parts of the Rio Grande Plains,
southern Edwards Plateau, and western Hill Country. The Mesoscale
Convective Vortex (MCV) responsible of multiple rounds of heavy rain
in combination with tropical moisture for the past several days is
now over the Pecos area. The MCV is forecast to push to the north
for the next 24 hours and favoring heavy rain rates especially
across the western Hill Country, southern Edwards Plateau, and the
Rio Grande Plains through at least Friday morning and where a Level
4 of 4 risk of Excessive Rainfall exists. On top of that, the
atmosphere supports spin up tornadoes as the 03Z VAD Wind Profile of
the DRT radar shows surface to 1 KM value of 243 m2/s2. All of this
to say that the night into the Friday morning period looks to be
another active one with heavy rain leading to flash flooding and
continuing with river flooding. Models are indicating new rainfall
amounts of 2 to 4 inches possible over a larger area with isolated
pockets up to 8 inches possible. This continues a situation with
up to ongoing considerable impacts from flash flooding and
moderate to major river flooding. For those areas that have
received 10+ inches of rainfall within the past 2 days, additional
0.5 to 1 inch per hour will be sufficient to trigger flash
flooding since the soil is saturated and runoff ends up in creeks,
rivers, and arroyos. Flood Watch remains in effect from a Llano
to Castroville to Pearsall and points west through noon Friday.

So for the next 12 hours or so, here are safety messaging lines we
will like to pass along:

Rivers, creeks, and arroyos can rise suddenly and rapidly! Locally
dry conditions near creeks and rivers should not be treated as a
guarantee of your safety! Normally dry areas can flood in these
conditions. Heed warnings, instructions from local and county
officials, and avoid unnecessary travel. Flash flooding can be
impossible to spot at night. Avoid flooded roadways. Conditions can
change drastically and suddenly. Have multiple reliable ways to
receive warnings and information from local/state officials both in
the daytime and at night. If you are in a low-lying location or near
a stream, have a plan and have a route to reach higher ground if
needed.

When this is going to be over? The weather conditions are forecast
to improve midday on Friday across most of the Hill Country,
southern Edwards Plateau, and Rio Grande while areas along and east
of Highway 281 stay dry. There is a low end chance for showers and
storms to affect Val Verde County in the afternoon with dry
conditions elsewhere. However, flooding and river flooding are
likely to be ongoing for several river basins and we urge residents
and visitors to be weather aware and following local officials for
latest information on street closures, river impacts, and other
weather related situations.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 1226 AM CDT Fri Jul 17 2026

Dry weather conditions continue into the weekend for the most part
with isolated to scattered showers and isolated thunderstorm
activity forecast to affect portions of Val Verde County on Saturday
afternoon as a mid level trough sits over that area. By Sunday, an
upper level high takes control across South Central Texas with
mostly sunny skies across the region and high temperatures back into
the 90s for most locations and upper 80s across the southern Edwards
Plateau. The work week looks dry as an upper level ridge remains in
control with clouds developing in the evening through the overnight
periods and dissipating mid to late mornings for partly cloudy to
mostly sunny days and highs in the mid 90s.

&&

.AVIATION...
(06Z TAFS)
Issued at 1214 AM CDT Fri Jul 17 2026

VCSH the rest of the night for most terminals except for KDRT
which will see some lingering VCTS the rest of tonight. MVFR
ceilings expected through daybreak before lifting to VFR during
the afternoon and evening. Winds will be out of the SE around
10-15 kts with gusts around 20 kts. Another round of lower
ceilings is expected after 06Z Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              91  76  92  75 /  10   0   0   0
Austin Bergstrom Intl Airport  91  76  92  75 /  10   0   0   0
New Braunfels Muni Airport     91  75  92  74 /   0   0   0   0
Burnet Muni Airport            89  74  91  72 /   0   0   0   0
Del Rio Intl Airport           88  75  90  75 /  30  10  10   0
Georgetown Muni Airport        91  75  92  74 /   0   0   0   0
Hondo Muni Airport             89  74  90  73 /   0  10   0   0
San Marcos Muni Airport        91  75  92  74 /  10   0   0   0
La Grange - Fayette Regional   92  76  93  74 /   0   0   0   0
San Antonio Intl Airport       90  76  91  75 /   0   0   0   0
Stinson Muni Airport           91  76  92  75 /   0   0   0   0

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until noon CDT today for TXZ171-183>190-202>204-
217>219-228.

&&

SHORT TERM...17
LONG TERM....17
AVIATION...MIA