611
FXUS64 KEWX 210510
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1210 AM CDT Fri Aug 21 2026

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

.KEY MESSAGES...
Updated at 1206 AM CDT Fri Aug 21 2026

- Heat Advisory in effect form the northern Hill Country, I-35
  Corridor, and Coastal Plains Thursday-Sunday.

- Brief and isolated storms possible over Central TX late Saturday.

- August heat wave continues with no significant rain or heat
  relief in sight.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 1206 AM CDT Fri Aug 21 2026

The massive subtropical ridge over the Wrn CONUS continues to
slowly edge eastward into West TX. A weak meridional flow over the
Central CONUS and a back door front stalling over NE TX will
generate enough moisture pooling for some convection, with
probably an extra element of compressional heating coming our way
for today. Thursday`s high temps topped out into the low end side
of Heat Advisory for both ambient and heat index criteria, and the
numbers may go up another degree or two today with the unstable
forcing well upstream to our NE. Overnight lows may also trend up
a degree or two with the stagnant are and low non-convective wind
speeds. For Saturday, expect more of the same, except that area of
instability to the NE might just get close enough for a stray
storm or two, and possibly some strong outflow winds.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 1206 AM CDT Fri Aug 21 2026

The brief opportunity to see a storm or two should abate by late
evening and we go right back into upper ridge dominance after the
moisture pooling disperses for Sunday. The ridge of high pressure
will hold over the region over the rest of the weekend and
continue building as the work week kicks off. By mid-week, the
center will slide between New Mexico and Texas keeping a warm,
sunny pattern on tap for the region. The scale of the heat will
need to be monitored in upcoming forecast cycles in case the heat
wave threatens some daily maximum temperature records.

&&

.AVIATION...
(06Z TAFS)
Issued at 1206 AM CDT Fri Aug 21 2026

VFR flight conditions continue with few low early morning clouds
across the I-35 terminals (KAUS, KSAT, and KSSF) Friday and again
Saturday morning. Otherwise, there may be few to sct high clouds
at times through the period. Expect for light to modest south-
southwesterly to south-southeasterly breezes with winds mainly of
around 10 kts or less.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry             104  79 105  80 /   0   0  20  20
Austin Bergstrom Intl Airport 103  79 104  79 /   0   0  20  20
New Braunfels Muni Airport    104  76 104  77 /   0   0  10  10
Burnet Muni Airport           103  77 104  77 /  10   0  20  20
Del Rio Intl Airport          103  78 105  78 /   0   0   0   0
Georgetown Muni Airport       102  79 104  80 /  10   0  20  20
Hondo Muni Airport            102  76 103  76 /   0   0   0   0
San Marcos Muni Airport       103  77 103  77 /   0   0  10  10
La Grange - Fayette Regional  104  77 104  78 /   0   0  20  20
San Antonio Intl Airport      102  79 103  78 /   0   0   0  10
Stinson Muni Airport          103  78 104  78 /   0   0   0   0

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT Sunday for TXZ171>173-191>194-
205>209-220>225.

&&

$$

SHORT TERM...18
LONG TERM....18
AVIATION...62