149
FXUS64 KEWX 150610 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
110 AM CDT Wed Jul 15 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1248 AM CDT Wed Jul 15 2026

- Intense rain rates and compounding effects from multiple rounds
  of storms will result in a dangerous flash flooding threat
  through Thursday.

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

- Pockets of an additional 10 to 20 inches of rain are possible
  within the highest risk areas, with broader totals of 2 to 6
  inches.

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

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

&&

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 130 PM CDT Tue Jul 14 2026

A significant threat of torrential rainfall, significant flash
flooding, and downstream river rises continues tonight. There is a
High Risk (the highest risk category, Level 4 of 4) of heavy rain
capable of causing flash flooding along the southern Edwards Plateau
and throughout the Highway 90 corridor west of San Antonio.
Considerable to locally catastrophic flash flooding is possible for
these areas. Significant downstream river flooding to Moderate or
Major flood stages will be possible. A Flood Watch highlighting the
potential for life-threatening flash flooding remains in effect from
now into Thursday evening for the southern Edwards Plateau, Rio
Grande, Winter Garden region, Hill Country, and I-35 corridor. While
the High Risk region delineates the area of greatest concern, heavy
rain will be capable of causing flash flooding anywhere within the
broader watch area.

As of noon Tuesday, up to a foot of rain has fallen in portions of
these areas, with the heaviest rains so far impacting Bandera,
Medina, and Uvalde counties. On top of these already considerable
amounts, another round torrential downpours is expected tonight. The
most persistent storms may produce over a foot of rain tonight into
Wednesday (between 10 and 20 inches) with extreme rain rates
exceeding 3 or 4 inches per hour at times. The southern Edwards
Plateau, western Hill Country, and Rio Grande Plains are at greatest
risk for significant additional rainfall. This could occur over the
same areas hardest hit from rains last night and this morning.

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! Heed warnings, instructions from local and
county officials, and avoid unnecessary travel. Flash flooding can
be impossible to spot at night. Make sure you have multiple reliable
ways to receive warnings. 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.

This morning`s upper-air sounding at Del Rio reported a precipitable
water of 2.26 inches, above the 99th percentile of atmospheric
moisture for mid-July. We expect similarly anomalous moisture to
continue to be available for new storms to draw in. An stationary
front at the surface and aloft is draped across the area,
concentrating moisture over our region. A mesoscale convective
vortex (MCV) is evident in radar imagery over the southern Edwards
Plateau and Rio Grande Plains, embedded within this area of
elevated moisture. This will be a primary trigger for heavy rain.
Additional rainfall is also ongoing throughout Central Texas
accompanying the broader band of convergence. While scattering and
somewhat lowered intensity of rains is anticipated and ongoing
this afternoon over South-Central Texas as low-level winds weaken,
the low-level jet is expected to intensify this evening with the
HREF mean guidance showing winds at 850mb becoming 10-15 kt
stronger than this morning. This will likely reinvigorate and
concentrate torrential rainbands around the MCV tonight, and this
looks to be the primary mechanism for flooding rainfall concerns.
The heaviest rainfall will likely be near the center and along the
south to eastern flanks of the disturbance. Most of the high-
resolution models position the center of MCV near the Rio Grande
tonight. This places the southern Edwards Plateau, western Hill
Country, and Rio Grande Plains at greatest risk for exceptional
amounts of additional rainfall capable of causing significant
flash flooding.

Intense bands of slow-moving torrential rainfall may persist late
tonight through Wednesday morning. Some decrease in activity is
possible Wednesday afternoon, with more spread out/lighter rainfall
consistent with the usual diurnal behavior of MCVs. However,
regional models show a continued zone of high humidity in the low
and mid-levels, and the MCV or related areas of concentrated
vorticity are will likely be present heading into Wednesday night.
The low-level jet is also forecast to be even stronger Wednesday
night... around 30-35 kt from the Rio Grande Plains to Edwards
Plateau. This means that Wednesday evening/night into Thursday
morning will likely be another timeframe for torrential rainfall
over these areas. The precise area of heaviest rain will depend on
where the MCV is located and orientation of the LLJ. Most models
show some westward shift as the MCV slides slightly north and west
in response to the strong ridging over the northern tier of
CONUS. Regardless, there could be considerable overlap with areas
already impacted by prolific rainfall, resulting in a heightened
risk for considerable to locally catastrophic flash flooding. The
greatest threat Wednesday into Thursday morning will again be
along the Highway 90 corridor west of San Antonio and southern
Edwards Plateau, with a round of extreme rain amounts possible.
This will likely add to elevated streamflows and prolong or
exacerbate downstream rises and impacts in rivers. The currently
active Flood Watch extends into Thursday evening. Total rainfall
amounts from this week`s heavy rain event may end up amounting to
over half of the normal annual rain total for some locations.

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.

&&

.LONG TERM...
(Thursday through next Tuesday)
Issued at 130 PM CDT Tue Jul 14 2026

The low/mid-level steering winds Thursday and Friday will be
directed towards the northwest. This will favor the MCV accompanying
the heaviest rains also moving towards the north or northwest. While
this implies that the rainfall later this week may not be as
concentrated as Tuesday/Wednesday, a strong plume of tropical
moisture is still forecast to trail the outgoing MCV, persisting
across South-Central Texas. Strong integrated vapor transport across
the Rio Grande Plains and Edward Plateau will continue to support
chances for heavy rainfall, especially at night when the low-level
jet is most intense. A Level 3 of 4 (Moderate) Risk for excessive
rainfall capable of causing flash flooding is highlighted by the
Weather Prediction Center for Thursday to Friday morning for the
southern Edwards Plateau, including the Del Rio, Rocksprings, and
Brackettville areas.

There are promising signals for an end to this heavy rain event
towards the end of the week. Surface high pressure is expected to
expand over the southeastern US into the Gulf. This will help to
smear out the remaining vorticity over Texas and reduce moisture
convergence aloft. Rain chances are forecast to generally decrease
during the day Friday into the weekend, but we encourage staying up
to date with the forecast and staying vigilant as the remaining
moisture could still support isolated rains over saturated soils.

The weekend looks drier for most of the area. The current long-range
ensembles and national model blend is also generally dry for early
next week, though specifics will depend on whether the dominant
ridge over the northern US will expand or drop south enough to
suppress activity over our area. For now, the model consensus favors
this depiction.

&&

.AVIATION...
(06Z TAFS)
Issued at 1248 AM CDT Wed Jul 15 2026

Some minor adjustments to the forecast have been made based on
recent radar trends. Showers will fill in along I-35 over the next
few hours, with TSRA favored 10-16Z SAT and SSF and 14-19Z AUS. We
kept a mention of some early morning TSRA at DRT, with a break for
the late morning and early afternoon hours. With daytime heating,
another round of convection may develop at KDRT. We will continue
to monitor radar trends and hi-res models and refine the timing of
TSRA this morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              83  72  87  74 /  80  40  60  40
Austin Bergstrom Intl Airport  83  72  87  74 /  80  40  60  40
New Braunfels Muni Airport     82  71  86  73 /  90  50  60  40
Burnet Muni Airport            81  70  84  72 /  90  50  50  30
Del Rio Intl Airport           83  71  84  72 /  90  90  80  80
Georgetown Muni Airport        83  71  86  73 /  80  40  60  30
Hondo Muni Airport             82  70  83  72 /  90  70  70  60
San Marcos Muni Airport        84  71  86  73 /  80  40  60  40
La Grange - Fayette Regional   84  73  87  75 /  70  20  50  10
San Antonio Intl Airport       82  73  85  75 /  80  60  60  50
Stinson Muni Airport           83  73  86  75 /  80  60  60  40

&&

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

&&

$$

SHORT TERM...27
LONG TERM....27
AVIATION...Platt