699
FXUS64 KEWX 080015
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
715 PM CDT Mon Jul 7 2025

...New UPDATE, AVIATION...

.UPDATE...
Issued at 703 PM CDT Mon Jul 7 2025

Only a few compact showers and storms and one western Val Verde
county cluster remain of today`s convection, so the watch is allowed
to expire. Higher res models still depict some isolated late
evening/overnight activity, mainly east of I-35. More locally heavy
rainfall will again be possible for daytime Tuesday, but mainly east
of I-35 where run-off impacts were not as severe.

&&

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 1247 PM CDT Mon Jul 7 2025

Abnormally moist air over South Central Texas continues to support
the risk of heavy downpours capable of causing flash flooding. A
Flood Watch is in effect for most of the region today.

Multispectral satellite imagery shows a weakening but still present
mesoscale convective vortex (MCV) over the Edwards Plateau and
northern Hill Country, which is very slowly drifting west. The steady
stream of moisture northward into this disturbance, as well as from
the broader mid-level trough of low pressure over our area, resulted
in the development of scattered showers and isolated thunderstorms
from the Hill Country down to the Rio Grande Plains in the morning
hours. The coverage and extent of rain has generally been less
today, with a lull noted in the early afternoon. However, the
atmosphere is only slightly less moist that previous days and
continues to facilitate chances for scattered rains and heavy rain
rates from the strongest storms: precipitable water values remain
above the 90th percentile for portions of the region, and this is
forecast to linger through tonight. Environmental conditions indicate
rain rates could range from 2 to 3 inches per hour, with locally
higher rates. Increased instability from daytime heating this
afternoon through breaks in cloud cover could also further enhance
rain rates. The combination of heavy downpours and relatively slow-
moving storms atop heavily saturated ground presents a risk of flash
flooding today to tonight. The highest risk areas include the
southern Edwards Plateau and Hill Country, with the risk periphery
extending into the Rio Grande Plains and I-35 corridor. The Weather
Prediction Center has indicated as high as a level 3 of 4 risk for
flash flooding.

As the trough and MCV gradually thin out and weaken, the lessened
flow of moisture should permit a decrease in the coverage of showers
and storms overnight, similar to what was experienced on Sunday. Most
of the high-resolution guidance does not show activity overnight,
but we cannot entirely rule out an isolated storm capable of
producing heavy rain rates given the deep atmospheric moisture still
in place.

Further weakening of the mid-level trough and whatever remains of
the MCV is anticipated tomorrow, in concert with the strengthening
of a ridge of high pressure over the Southwestern US. Regional model
guidance indicates that precipitable water values should drop below
2.0 inches for most with a decrease in moisture throughout the
atmosphere. That said, a trough of low pressure is forecast to push
onshore from the Gulf on Tuesday. The arrival of this disturbance is
forecast to be accompanied by moderate chances of scattered showers
and isolated storms enhanced by the seabreeze, mainly during the
afternoon and evening for the Coastal Plains into the I-35 corridor.
While the atmosphere will likely not be as supportive of the very
high rain rates seen over the past few days, remain vigilant as
these coastal showers could push over highly saturated ground.

Clouds and rain are expected to keep daytime temperatures below
average in the upper 80s and low to mid 90s.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 1247 PM CDT Mon Jul 7 2025

The coastal mid-level trough from Tuesday pushes farther inland
Wednesday, linking up with a trough over the Mississippi and Red
River valleys to produce a convergent shear axis over Texas in
between two subtropical ridges. This supports chances for showers
and thunderstorms during the afternoon, likely drifting west during
the day. Atmospheric moisture content is expected to be lower during
this period as slightly drier continental air aloft gets pulled in
from the north. The shear axis weakens and moves farther west
Thursday into Friday with a drying trend overlapping. This should
reduce chances and coverage of shower activity those days. Low
chances of isolated showers and a thunderstorm or two each afternoon
are possible over the Coastal Plains as modest southerly moisture
transport works its way into the residual weakness between the two
ridges. Similar activity looks to continue into the weekend with the
overall weather setup holding steady, though medium-range model
guidance indicates a slight uptick in rain chances over the weekend.
During the latter half of this week, temperatures are expected to
warm to near-normal levels as cloud cover tapers off. High dew
points are forecast to push heat indices over 100 mainly for the
Coastal Plains and I-35 corridor.

&&

.AVIATION...
(00Z TAFS)
Issued at 703 PM CDT Mon Jul 7 2025

We`ll go back to the usual early to mid summer diurnal trend of 07Z
to 17Z window for MVFR cigs with mainly after daybreak cigs at DRT.
Winds are mainly light, but an outflow boundary boost along I-35 will
be noted in the first hour with some gusts to 20 knots possible.
Scattered storms will be possible along I-35 Tuesday afternoon. Will
wait for the 00Z data to start trickling in before choosing the time
window and whether to go Prob30 or Tempo.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              75  92  74  93 /  20  30  10  30
Austin Bergstrom Intl Airport  75  92  74  93 /  30  30  10  30
New Braunfels Muni Airport     73  91  72  93 /  20  30  10  30
Burnet Muni Airport            73  89  72  90 /  10  20  10  30
Del Rio Intl Airport           76  94  76  95 /  10   0   0  10
Georgetown Muni Airport        74  92  73  92 /  20  20  10  30
Hondo Muni Airport             73  91  73  91 /  10  10   0  20
San Marcos Muni Airport        73  92  72  93 /  20  30  10  30
La Grange - Fayette Regional   75  92  74  92 /  30  50  10  40
San Antonio Intl Airport       76  91  75  92 /  10  20  10  20
Stinson Muni Airport           76  93  75  94 /  10  20  10  20

&&

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

$$

Short-Term...Tran
Long-Term...Tran
Aviation...18