790
FXUS64 KEWX 191048
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
548 AM CDT Sat Sep 19 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 539 AM CDT Sat Sep 19 2026

- Low chances (15-30%) for showers or storms over the Hill Country
  and southern Edwards Plateau Sunday night.

- Low chances for rain across South Central Texas next week with
  most staying dry.

- Above average temperatures continue into late September.

&&

.SHORT TERM...
(Today through Sunday)
Issued at 1226 AM CDT Sat Sep 19 2026

The batch of moisture that offered spotty rain the last two days
mostly south of Interstate 10 is on its way out and a drier airmass
is spreading westward across South Central Texas, distinctly evident
on water vapor imagery and GOES-derived TPW imagery.

This drier air aloft will set the tune for a mostly sunny Saturday
with highs in the mid to upper 90s for most, with a few spots in the
Rio Grande Plains reaching the low triple digits, and Sunday should
be similar. Overnight lows will continue to be mild and in the 70s.
The presence of mid-level ridging and this drier airmass will keep
rain out of the forecast for most of the region through Sunday
afternoon, though diffuse vorticity could bring an isolated
weakening shower or storm into rural Val Verde County after sunset
today. The ridge is expected to weaken some late this weekend into
early next week as troughing moves across the western CONUS. A
shortwave impulse, most apparent in the upper-troposphere, is
expected to accompany some of this troughing as it moves across
West/North Texas late Sunday. Most of the resulting isolated to
scattered thunderstorms are favored to form north of our area, but
some activity could spill into Hill Country and southern Edwards
Plateau to the Del Rio area late Sunday. The risk of severe weather
or excessive rainfall is low, but it will be worth being on the
lookout for potential late night storminess for those areas late
Sunday into early Monday.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 1226 AM CDT Sat Sep 19 2026

Despite some of the increased troughiness out west, the jet stream
is not in an especially favorable latitude to more convincingly shove
ridging out of our area. This will allow the ridge to reestablish
towards midweek, keeping the overall pattern of unseasonably warm
temperatures going for late September. Forecast highs remain in the
mid to upper 90s with lows in the mid to upper 70s, aside from the
upper 60s filtering into the higher terrain in the Hill Country.
Peak afternoon heat indices are forecast to continue poking above
100F for many. While the bulk thermal energy in the low to mid
troposphere isn`t strongly suggestive of record-breaking heat, it
does look like we will continue to straddle the upper ends of the
distribution for both daytime and nighttime temperatures at least
through midweek.

Rain chances stay low in the forecast for next week, but aren`t
entirely out of the picture and there is the possibility that the
pattern could allow for recurring isolated rain chances during the
early half of the week. Depending on how the convection late
Sunday/early Monday evolves, residual boundaries and a band of
higher 700mb theta-e may stay draped over Central Texas before it
gets cycled out by the ridge. For this reason, low rain chances up
to around 25 percent remain in the forecast mainly for the
afternoon/early evening hours during the upcoming workweek across
varying portions of South Central Texas. Recent runs of the EPS and
AIGEFS lean towards slightly wetter depictions while the GEFS and
ECMWF AIFS have tended to be dry, so uncertainty is still high and
will hinge on how the aforementioned setup establishes. Regardless,
with synoptic forcing remaining weak, rains are not expected to be
widespread and most are likely to remain dry.

&&

.AVIATION...
(12Z TAFS)
Issued at 539 AM CDT Sat Sep 19 2026

Winds will generally remain east-southeasterly but remain less
than 10 kts. Opted to leave prevailing MVFR at SAT and SSF with a
tempo to account for uncertainty and a possible back and forth
MVFR/VFR scenario this morning through 15Z. VFR should prevail
beyond that but there is still an outside shot of MVFR stratus
returning tonight after 09Z. No other major changes for this
forecast update.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry             100  75 100  76 /   0   0   0  10
Austin Bergstrom Intl Airport  99  74 100  75 /   0   0   0  10
New Braunfels Muni Airport     98  73  98  74 /   0   0   0   0
Burnet Muni Airport            96  72  97  72 /   0   0   0  20
Del Rio Intl Airport           99  77  99  75 /   0  10   0  20
Georgetown Muni Airport        99  74  99  75 /   0   0   0  10
Hondo Muni Airport             96  72  97  73 /   0   0   0  10
San Marcos Muni Airport        99  73  99  74 /   0   0   0  10
La Grange - Fayette Regional   98  72  99  75 /   0   0   0   0
San Antonio Intl Airport       96  75  97  76 /   0   0   0  10
Stinson Muni Airport           98  74  99  75 /   0   0   0   0

&&

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

$$

SHORT TERM...Tran
LONG TERM....Tran
AVIATION...MMM