868 
FXUS64 KEWX 112333
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
633 PM CDT Sun May 11 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Monday night)
Issued at 145 PM CDT Sun May 11 2025

- Warming trend begins. 

Satellite imagery shows the persistent upper low centered over 
northeastern Louisiana this afternoon, just far away from South 
Central Texas now to ease its influence on our weather. Some high 
clouds are expected this afternoon mainly from the Hill Country and 
areas east associated with the upper low, with clear skies 
prevailing to the west. Chances for showers and thunderstorms look 
to stay east of our area this afternoon as ridging begins to build 
over the west Texas. Afternoon highs will generally be in the 80s, 
except along the Rio Grande where the low 90s will be common. Mostly 
clear skies and light wind will allow tonight's temperatures to drop 
into the 50s for most. The upper low continues its eastward 
progression on Monday with northwest flow over our area. Mid-level 
and high level clouds will stream overhead tomorrow afternoon but 
will have little impact on temperatures as highs ramp up into the 
upper 80s to around 100 degrees. Low temperatures Monday night into 
Tuesday will also experience a warm up into the 60s. The real story 
comes in the extended forecast as an early season heat wave begins. 

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 145 PM CDT Sun May 11 2025

- Daily and Monthly high temperature records are at risk Tuesday
  through Thursday. 

- Moderate to Major risk of heat-related impacts beginning Tuesday.

- Now is the time to ensure you have access to effective cooling.
  Additional safety information and resources can be found at the
  following websites: www.heat.gov and www.weather.gov/safety/heat

One of the more dramatic temperature swings in recent memory is
expected to take place between Monday and Tuesday. It was a great
start to the month of May, having normal to below normal temperatures
and a couple of multi-day stormy periods to help limit the long term
drought impacts over the region. Now a sobering dose of reality
returns with one of the hottest May heat waves of all time set to
begin Tuesday. 

Tuesday and Wednesday in particular are of highest concern, since 
the outdoor conditioning hasn't happened for those used to spending 
time outdoors. As a thermal ridge invades from the west, the 
southwest boundary layer winds will bring very dry plateau air into 
the region with the gusty conditions mixing dry air down to help keep
the heat index values in check over at least the western counties 
the first two days. This means that western counties will get the 
driest air and thus the hottest ambient temperatures. Low level winds
will not be as much out of the SW on Wednesday for central counties,
and the H8 thermal ridge will be overhead signaling the hottest 
feeling day of the period whether be ambient or apparent. We trended 
back slightly on the ambient max over central counties versus what 
the raw model output has suggested, but we may also see the apparent 
temperature climb higher due to all the moisture still trapped in the
soil and vegetation. Regardless Wednesday will probably be the day 
where monthly record maxes could have the highest chance of being 
broken. Thursday is expected to be almost as hot, but the thermal 
ridge will not be as concentrated, as the SW winds aloft show a 
lighter plateau influence and H5 heights begin to fall over W TX to 
possibly open up a more favorable pattern to bring in some high 
clouds and perhaps a few orographic storms west of the the forecast 
area. Hopefully, after we get a taste of Tuesday and Wednesday, most 
people will have probably adapted to how they spend their day and 
secure some shelter indoors at least a portion of the day, leading to
few impacts. Going forward into next weekend, well above normal 
temps remain, and heat index values to triple digits for most areas 
are a good bet. As for rain chances, a sharpening SW flow aloft over 
TX next weekend could finally open the door for a few high terrain 
storms that could cross into our forecast area.

&&

.AVIATION...
(00Z TAFS)
Issued at 633 PM CDT Sun May 11 2025

VFR conditions through the TAF period. NW winds quickly diminishing,
becoming less than 5KT overnight. Monday afternoon a SSE wind around
5-8KT is forecast to develop along the Rio Grande, and NW to W wind 
around 5-8KT across the Hill Country, I-35 corridor and Coastal 
Plains, becoming S to SE Monday evening.

&&

.FIRE WEATHER...
Issued at 145 PM CDT Sun May 11 2025

Locally elevated fire weather conditions are occurring this afternoon
over western counties. Tuesday and Wednesday, elevated to near 
critical fire weather conditions are possible over localized areas 
west of I-35, as gusty south winds turn more out of the southwest but
three or four days of drying through evapotranspiration could help 
pull back on the potential heat index, at least as 

each afternoon over western counties. Triple digit heat could come 
with RH values as low as 10 to 15 percent. Low RH values could 
continue over the Edwards Plateau and Rio Grande Plains into next 
weekend, and afternoon temperatures are expected to remain well above
normals through the period. The extended period of hot and dry 
weather will lead to more drying of area fuels, which could lead to 
more active fire weather conditions going forward.

&&

.CLIMATE...
Issued at 255 AM CDT Sun May 11 2025

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

         TUE       WED       THU       FRI       SAT
        05/13     05/14     05/15     05/16     05/17
------------------------------------------------------
AUS    94/1967*  96/2003   96/2003   97/2018*  97/2018
ATT    98/1925   97/2022   98/1925   99/2022*  99/2022
SAT    98/2009*  97/2022*  98/2022   97/2022* 100/2022
DRT   104/1995  103/2003  102/2022  107/2013  105/2013

RECORD MAX TEMPERATURES FOR MAY
-------------------------------
AUS   102 ... set on 05/07/1998
ATT   104 ... set on 05/24/1924
SAT   104 ... set on 05/31/2004
DRT   112 ... set on 05/26/2024

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              58  92  64 101 /   0   0   0   0 
Austin Bergstrom Intl Airport  55  91  62 100 /   0   0   0   0 
New Braunfels Muni Airport     56  94  61 102 /   0   0   0   0 
Burnet Muni Airport            56  90  64 101 /   0   0   0   0 
Del Rio Intl Airport           60  98  68 107 /   0   0   0   0 
Georgetown Muni Airport        55  89  62 101 /   0   0   0   0 
Hondo Muni Airport             55  94  61 105 /   0   0   0   0 
San Marcos Muni Airport        55  92  61 101 /   0   0   0   0 
La Grange - Fayette Regional   56  88  64  97 /   0   0   0   0 
San Antonio Intl Airport       58  94  65 103 /   0   0   0   0 
Stinson Muni Airport           58  95  64 103 /   0   0   0   0 

&&

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

&&

$$

Short-Term...27
Long-Term...18
Aviation...76