634
FXUS64 KEWX 151838
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
138 PM CDT Wed Jul 15 2026

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

.KEY MESSAGES...
Updated at 130 PM CDT Wed Jul 15 2026

- The forecast remains relatively unchanged with intense rain
  rates and compounding effects from multiple rounds of storms
  resulting in a dangerous flash flooding threat through Thursday.

- Considerable to locally catastrophic impacts from flash flooding
  are likely for the southern Edwards Plateau, Rio Grande, western
  Hill Country, and U.S. 90 corridor west of San Antonio.

- Pockets of an additional 10 to 15 inches of rain are possible
  within the highest risk areas, with broader totals of 2 to 6
  inches.

- Potential for significant to catastrophic river flooding in the
  Nueces, Frio, and Medina river basins and significant flooding
  in the Pecos, Rio Grande, and San Antonio river basins.

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

&&

.SHORT TERM...
(Tonight through Thursday night)
Issued at 130 PM CDT Wed Jul 15 2026

Significant rainfall capable of life-threatening flooding is again
expected tonight through tomorrow morning. This includes likely
impacts from considerable to locally catastrophic flash flooding
along the U.S. 90 corridor west of San Antonio including the
southern Edwards Plateau, Rio Grande, and western Hill Country, plus
the renewed potential for significant mainstem river flooding into
Moderate and Major flood stages in the Pecos, Rio Grande, Nueces,
Frio, Medina, and San Antonio River basins. This is in addition to
significant to catastrophic river flooding already expected in the
Nueces, Frio, and Medina basins as floodwaters from earlier rains
continue to move downstream. The potential for renewed impacts from
flash and river flooding include areas already hard hit by recent
flooding. While these locations are at greatest risk and highest
confidence for seeing significant impacts, a Flood Watch remains
in effect for a broader area across the I-35 corridor, the Hill
Country, Rio Grande Plains, and southern Edwards Plateau through
Thursday. Dangerous flash flooding from torrential downpours will
be possible for all of these areas.

In the highest risk areas, the potential continues for pockets of an
additional 10 to 15 inches of rain through noon Thursday. Regional
values in the 2 to 6 inch range are possible for those areas,
with 1 to 4 inch totals over the remaining portions of the Flood
Watch area. Prolific rain rates will again be possible tonight and
Thursday morning, with rates potentially reaching 2 to 4 inches
per hour. It will not make much rain to produce major concerns.
With how saturated soils are, even rates of 0.5 to 1 inch per hour
will be sufficient to trigger flash flooding, rapidly accumulating
into creeks and arroyos. Additionally, steep rises along the Frio,
Medina, and Nueces rivers and their tributaries to Moderate or
Major flood stage are already occurring and flowing downstream
with the potential for catastrophic impacts. Heavy runoff and
rains in these or other river basins may produce further rises
which could impact downstream areas far the heaviest rains.

Like yesterday, rain has fanned out this afternoon over a wider area
across South Central Texas, though pockets of torrential rain are
still occurring mainly along the eastern edge of the Hill Country
and I-35 corridor. The flood event is not over! While rain
coverage overall is expected to decrease some this afternoon for
most areas, showers and storms should begin redeveloping again
this evening with the heaviest rain likely occurring during after
midnight into the early morning hours. This redevelopment is most
likely to occur between San Antonio and the Rio Grande, over the
southern Edwards Plateau, western Hill Country, and U.S. 90
corridor.

The well-defined mesoscale convective vortex responsible for last
night and this morning`s rains is moving north through the Hill
Country. Even if this disturbance individually leaves South-Central
Texas, a broader area of vorticity persists over the southern
Edwards Plateau and Rio Grande, and will be the catalyst for heavy
rainfall tonight. Convergence and a robust low-level jet will again
support torrential downpours. The jet tonight looks even stronger
than previous nights, with the HREF mean showing 30-35 kt values at
850mb. Most models indicate the vorticity will track slowly north
and west, guided by flow from a retrograding upper-level low. While
its location will dictate to some degree where bullseyes of extreme
rain totals will set up, the massive amounts of rainfall received
the last two days combined with the large amount of tropical
moisture continuing to push into the region indicates that much of
the southern Edwards Plateau and Highway 90 corridor west of San
Antonio remain a High Risk (Level 4 of 4, the maximum level) for
excessive rains capable of flash flooding. Preceding rains have
saturated much of the area`s soils to an exceptional degree. Very
little rain will be required for flash flooding to recommence
tonight.

The most imminent period of heightened concern for flash flooding is
tonight through Thursday morning. Heavy rains may linger into
Thursday afternoon across the area as tropical moisture flows across
the Edwards Plateau and Hill Country, though rain coverage should
ease up some. The main forcing for these storms should continue to
move further away from the area towards the north. Nonetheless,
tropical moisture will continue to move south to north behind the
outgoing disturbance, setting up for another round of potentially
heavy rainfall Thursday night into Friday morning mainly over the
southern Edwards Plateau, Rio Grande, and western Hill Country. Once
again, these rains could impact areas already hard hit. Slightly
faster mid-level winds should allow storms to move a little faster,
but multiple rounds of heavy rains may occur again. There is a
Moderate Risk (Level 3 of 4) of excessive rain capable of causing
flash flooding Thursday through Friday morning, with the rains most
likely occurring during the overnight/morning hours. The risk area
for heavier rains and flash flooding Thursday night through Friday
morning is expected to shift slightly north and west compared to
tonight`s potential, but moisture will remain plentiful across
South Central Texas.

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.

&&

.LONG TERM...
(Friday through next Wednesday)
Issued at 130 PM CDT Wed Jul 15 2026

Rain chances are expected to decrease Friday afternoon and then over
the weekend as high pressure over the Gulf shifts closer to our
area, with an accompanying reduction in moisture. Some isolated
showers may still move over South-Central Texas this weekend as
southerly flow remains intact aloft, but the overall atmosphere
should be drier. Keep in mind that areas hardest hit by the week`s
rains will be susceptible to relatively modest amounts of new
rainfall, so even a stray shower could cause nuisance flooding if it
moves over the southern Edwards Plateau, western Hill Country, or US
90 corridor. Overall drier conditions and clearer skies will restore
temperatures back to typical summer highs in the 90s for the first
time since the start of the week.

The weather pattern next week favors drier conditions continuing. A
ridge should rebuild over the Central Plains, close enough to our
area this time around to provide enough sinking motion to suppress
rain chances and provide more typical summertime and sunny weather
for South-Central Texas.


&&

.AVIATION...
(18Z TAFS)
Issued at 130 PM CDT Wed Jul 15 2026

Activity continues to affect AUS/SAT this afternoon with heavy rain
at times, reducing VSBYs. Currently have MVFR to VFR conditions
across terminals this afternoon. Generally expecting showers and
thunderstorms to continue through this TAF period but should dry out
towards the end of the period. Expect IFR to MVFR CIGs and MVFR
VSBYs except in and around thunderstorms where VSBYs could reduce to
IFR/LIFR at times. Winds are generally east to southeast at less
than 10KT but expect gusts from nearby storms up to around 20KT or
higher.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              72  87  74  91 /  40  50  30  10
Austin Bergstrom Intl Airport  72  87  74  91 /  30  60  30  10
New Braunfels Muni Airport     72  86  74  90 /  50  60  30  10
Burnet Muni Airport            70  85  72  89 /  50  60  30  10
Del Rio Intl Airport           72  85  73  88 /  90  90  70  50
Georgetown Muni Airport        70  86  73  90 /  30  50  20  10
Hondo Muni Airport             71  84  73  88 /  70  60  50  10
San Marcos Muni Airport        71  87  74  90 /  40  50  30  10
La Grange - Fayette Regional   73  88  75  91 /  10  40  20  20
San Antonio Intl Airport       73  85  75  89 /  60  60  40  20
Stinson Muni Airport           73  86  75  90 /  60  50  30  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Thursday evening for TXZ171>173-183>192-
202>207-217>219-228.

&&

$$

SHORT TERM...Tran
LONG TERM....Tran
AVIATION...99