384
FXUS64 KEWX 151041
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
541 AM CDT Fri May 15 2026

...New AVIATION...

.KEY MESSAGES...

- Mostly dry this weekend, then stormy with heavy rainfall possible
  for much of next week.

- Increasing humidity and heat indices through Tuesday, with some
  spots feeling like 100-105+ Sunday, Monday, and Tuesday.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 129 AM CDT Fri May 15 2026

The capping inversion is expected to hold over the area Friday into
Saturday, but some higher terrain activity in Mexico and West TX
could threaten to send a stray storm toward the Val Verde County
border Friday evening. Low amplitude ridging over TX continues to
slowly transition towards a less stable SW flow aloft pattern going
into the weekend. A gusty south breeze will continue to fill the
nighttime air with increasing gulf moisture, but for Friday, the
layer of dry air at the top of the mixed layer will be less
effective in mixing down to lower afternoon surface dew points, so
the warm conditions for the afternoon will carry a higher humidity
and heat index. They will be somewhat typical for a mid May
afternoon Friday, but the increasing trend will continue. Low clouds
will unable to get started Thursday morning but should cover a good
portion of the CWA by the daybreak hours Friday and Saturday. By
Saturday afternoon the heat indices will get to the point where we
may need to put out some cautionary messaging those spending extra
time outdoors.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 129 AM CDT Fri May 15 2026

The continued warming and moisture loading will continue to escalate
Sunday, and conditions could send heat index values to the near the
points of consideration for heat advisories Monday and Tuesday. We
think the HI thresholds of 110 West & 108 East for our area are
mostly safe but that call should be more easy to make by Sunday.

Saturday night into Sunday the troughing developing upstream over the
Wrn CONUS sends a shortwave piece of energy across the Srn Rockies
into the Central Plains, but at the same time will lower heights
over W and Central TX. Deterministic models do not show an impact on
the dry-line, but with moisture continuing to load up over Central
TX, do show a low chance of streamer convection cluster over our
central counties. While there is skepticism over whether the cap can
be overtaken at this spot, it`s only a 15-20 percent indication. By
Monday afternoon the broad SW aloft pattern over TX has made the
expansion to make any location in our CWA a candidate for an
isolated storm or two. Capping is still expected to be fairly tough
to overcome at this time, and confidence on this period remains too
low for us to 2nd guess the NBM guidance. By Tuesday however, there
should be enough escalation from activity erupting off higher
terrain and a potential area of convection possibly propagating south
from a NW TX frontal boundary that we should see better coverage.
And here we go throughout the full work week of storm initiation
driven by high Pwat value pooling, MCV`s, MCS`s, and remnant
boundaries to paint a stormy, but vague picture. It is assumed that
one trend will be more predictable in that the areas of daily
convection should take a toll on the temperatures and heat indices.
There could be a mid-week front, but there isn`t enough model
support to specify, and if the front did get here, the impact on
temperatures would probably mainly cloud-cover dependent.

At some point we`ll also want to address a potential heavy rain
threat. Given a wide variety of model solutions, we`ll assume
coverage begins fairly low, which might favor a slow start and
appropriate messaging to point more towards the middle of the
week.

&&

.AVIATION...
(12Z TAFS)
Issued at 538 AM CDT Fri May 15 2026

MVFR ceilings have settled over the Austin and San Antonio areas.
DRT remains VFR and should remain VFR through the upcoming TAF
period. VFR skies will return to Austin and San Antonio by late
morning. Winds will increase and become gusty by late morning.
Gusty winds should continue into the evening. MVFR ceilings will
return early in the overnight period tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              92  71  92  75 /   0   0   0  10
Austin Bergstrom Intl Airport  92  72  92  77 /   0   0   0  10
New Braunfels Muni Airport     92  69  91  75 /   0   0   0   0
Burnet Muni Airport            88  69  87  73 /   0   0   0   0
Del Rio Intl Airport           96  72  94  76 /   0   0   0   0
Georgetown Muni Airport        90  71  90  74 /   0   0   0   0
Hondo Muni Airport             93  70  92  75 /   0   0   0   0
San Marcos Muni Airport        92  71  92  76 /   0   0   0   0
La Grange - Fayette Regional   91  71  90  76 /   0   0   0  10
San Antonio Intl Airport       93  71  92  76 /   0   0   0   0
Stinson Muni Airport           94  71  92  76 /   0   0   0   0

&&

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

$$

SHORT TERM...17
LONG TERM....17
AVIATION...05