457
FXUS64 KEWX 152321
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
621 PM CDT Tue Sep 15 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 621 PM CDT Tue Sep 15 2026

- A Heat Advisory remains in effect for the coastal plains, Williamson,
  and Travis Counties until 7 PM.

- A Rangeland Fire Danger Statement continues until 8 PM today for
  the Rio Grande plains and portions of the southern Edwards
  Plateau due to gusty southeast winds and low humidity values.

- Increased moisture Thursday into Friday brings a chance for
  convection to areas generally along and east of I-35.

&&

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 200 PM CDT Tue Sep 15 2026

The forecast for today remains on track and see no reason to
adjust the ongoing Heat Advisory in effect until 7 PM CDT for
portions of the I-35 corridor into the coastal plains region.
Southeasterly winds in the lower levels will continue tonight and
again Wednesday night, leading to very warm overnight low
temperatures. The NBM looked a little low with regards to lows and
have bumped up temperatures slightly based on persistence. On
Wednesday, it will be warm again across south central Texas. The
models do show a subtle weakening of the low-level thermal ridge
tomorrow, and this should allow temperatures to ease slightly. For
now, we will hold off on a Heat Advisory for Wednesday.

&&

.LONG TERM...
(Thursday through next Tuesday)
Issued at 200 PM CDT Tue Sep 15 2026

Mid and upper level high pressure centered over the southeastern
U.S. will continue to be the main influence on our weather across
south central Texas through the end of the week and into early
next week. A surge of low-level moisture on Thursday into Friday
along with daytime heating should aid in the development of
isolated to scattered convection for areas generally along and
east of the I-35 corridor. The NBM pops look a bit high, but did
opt to keep scattered rain chances (30-50%) over the coastal
plains with rain chances closer to 20% farther west into the I-35
corridor.

Moisture levels decrease rather quickly for the upcoming weekend
as the high pressure over the southeastern U.S. builds into the
southern U.S. plains. The latest NBM shows some rain chances
returning to a good portion of the region early next week as high
pressure begins to weaken. Given the current suite of operational
models, we are a bit skeptical of this. However, if a weak frontal
boundary can manage to slide southward early next week, our rain
chances would improve. Temperatures continue to remain above
normal through the period.

&&

.AVIATION...
(00Z TAFS)
Issued at 621 PM CDT Tue Sep 15 2026

VFR conditions with breezy south to southeasterly prevailing wind
continues through the evening before eventually weakening overnight.
There is large uncertainty in models regarding low CIGs
developing after 09Z, but with an increase of moisture expected,
have opted to continue mention of prevailing MVFR at KSAT/KSSF and
TEMPO mention at KAUS. If CIGs do develop, IFR CIGs will also be
possible through 14Z before clouds lift. Expect prevailing winds
to orient more east-southeast to easterly after by 18Z at
KSAT/KSSF/KAUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              78 100  78  99 /   0   0   0  20
Austin Bergstrom Intl Airport  76 100  77  98 /   0   0   0  30
New Braunfels Muni Airport     76  99  75  97 /   0   0   0  30
Burnet Muni Airport            75  97  74  95 /   0   0   0  10
Del Rio Intl Airport           77 101  77  99 /   0   0   0   0
Georgetown Muni Airport        77  99  77  98 /   0   0   0  20
Hondo Muni Airport             74  99  74  97 /   0   0   0  10
San Marcos Muni Airport        75 100  75  98 /   0   0   0  30
La Grange - Fayette Regional   77  99  77  97 /   0  10   0  50
San Antonio Intl Airport       77  99  78  97 /   0   0   0  20
Stinson Muni Airport           77 100  77  99 /   0   0   0  30

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT this evening for TXZ173-192>194-209-
225.

&&

$$

SHORT TERM...Platt
LONG TERM....Platt
AVIATION...Tran