511
FXUS64 KEWX 181710
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1210 PM CDT Sun May 18 2025

...New AVIATION...

.SHORT TERM...
(Today through Monday)
Issued at 211 AM CDT Sun May 18 2025

Key Messages:

- Hot and humid conditions continue today and Monday with elevated
heat index values.

-Low storm chances in the northern portions of the southern Edwards
Plateau and Hill Country today, and then the northern Hill Country
and I-35 corridor Monday.

Decaying thunderstorms over the Rio Grande Plains are seen early
this morning with any precipitation from these features expected to
end before sunrise. Ahead of these storms, weakening anvil showers
have produced gusty wind as they dissipate with a few sites
reporting gusts up to around 40 mph, though that should be their
peak. Low clouds are building over the area keeping morning lows in
the 70s areawide. Have continued the mention of haze in the morning
forecast due to agricultural burning in Mexico.

Another hot and humid day is in store with highs in the mid and
upper 90s east and in the triple digits along the Rio Grande and
over the Rio Grande Plains. Widespread heat index values will be
from around 103-107 while further west values may reach up to around
111 degrees. Wind, especially in the eastern half of the area, will
be gusty today and this evening with gusts from 25 to 30 mph common.
Models continue to favor storm initiation north of the area along
the dryline, but do have some low end precipitation chances mainly
in the northern portions of the southern Edwards Plateau and Hill
Country. If a storm does form over our area, it could be strong to
severe with large hail and damaging wind gusts the main hazards.

Tonight will be warm again with another round of low cloud cover.
The dryline moves further east into our area Monday bringing
temperatures up in the west Monday afternoon, though drier
conditions should limit heat indices. Hot and humid conditions
continue in the east. The best storm potential this day remains
north of the area, but low chances still exist for portions of the
northern Hill Country and I-35 corridor with the potential for any
storms to become severe.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 211 AM CDT Sun May 18 2025

Key Messages:

- The heatwave and heat related impacts continue with additional
  temperature records possibly being broken Tuesday.

- Chances for showers and storms decreasing Tuesday with arrival of a
  cold front with a slight cooldown in temps for Wed and Thursday.

The early record breaking heat continues through Tuesday. Several
weak disturbances move into the region thus possibly limiting just
how high actual air temps can go due to the increased moisture and
abundant cloud cover. However, the increased moisture could actually
cause our heat indices to be even warmer then what we have previously
been seeing, definitely something to watch for. One of these
disturbances will impact our area late monday night as a shortwave
moving through the southern Plains looks to send the dry line back
east into the Hill Country and I-35 corridor into Tuesday, with a
cold front eventually overtaking it Tuesday night. Confidence is
increasing that we may not see much as models are showing storms
firing off further to our east then previously thought. It should be
noted that model trends can and likely will continue to change as
new information comes in. Additionally, models generally have a
difficult time with such small scale features. The best chances still
look to be along and West of the I-35 Corridor and into the Coastal
Plains

Regarding temperatures the cold front mentioned prior could bring
some temporary relief from the heat for Wednesday and Thursday,
however confidence in the strength and position remains low at this
time. Regardless, temperatures will remain well above normal through
the end of the forecast period with high temperature records likely
to be tied or broken through Tuesday. Temperatures cool somewhat
into the low 90s vs the upper 90s/100s that we previously have been
seeing for Wednesday and Thursday. This cooldown is short-lived
because by Friday temperatures and humidity look to be on the
increase as southerly Gulf moisture streams into the area. Come
Saturday temps once again approach the upper 90s to near 100.
Please make sure you and your loved ones have a way to stay cool
during this early season heatwave. Additional heat safety information
and resources can be found at the following websites:
www.heat.gov and www.weather.gov/safety/heat|

&&

.AVIATION...
(18Z TAFS)
Issued at 1110 AM CDT Sun May 18 2025

Remaining stratus west of SAT will continue to erode over the next
hour, with VFR conditions areawide for the afternoon and evening,
outside of any isolated SHRA/TSRA activity. Weak mid level forcing
has generated isolated TSRA midday just north of a ERV-T82 line as
well as isolated SHRA across eastern areas near 3T5. The main
forcing for additional convective activity through the afternoon and
early evening will be located primarily near and north of ERV-BMQ
line. Stratus is forecast to re-develop late this evening and
overnight across the Coastal Plains, I-35 corridor, and Hill Country,
producing MVFR ceilings into Monday morning. S to SE winds 12-18KT
through the afternoon and evening with gusts 22-28KT.

&&

.CLIMATE...
Issued at 236 PM CDT Fri May 16 2025

RECORD MAX TEMPERATURES SUNDAY THROUGH TUESDAY
(* TIED RECORD WITH MOST RECENT OCCURRENCE SHOWN)

         SUN        MON    TUE
        05/18      05/19   05/20
----------------------------------------------
AUS    97/2022    97/2006  99/2008
ATT    98/2022    98/2022* 101/2008
SAT   101/2022   101/1989 100/1996
DRT   107/2024   108/2020 105/1973

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              76  97  73  97 /   0  20  20  10
Austin Bergstrom Intl Airport  76  97  72  97 /   0  20  20  10
New Braunfels Muni Airport     76  98  71  99 /   0  10  10  10
Burnet Muni Airport            74  94  67  94 /  10  20  20   0
Del Rio Intl Airport           79 105  73 102 /  10  10  10   0
Georgetown Muni Airport        75  94  70  93 /  10  20  20  10
Hondo Muni Airport             75  99  70 100 /  10  10  10   0
San Marcos Muni Airport        77  97  71  98 /   0  20  20  10
La Grange - Fayette Regional   77  94  74  96 /   0  10  10  10
San Antonio Intl Airport       77  98  74  99 /   0  10  10  10
Stinson Muni Airport           77 100  75 101 /   0  10  10  10

&&

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

&&

$$

Short-Term...27
Long-Term...CJM
Aviation...76