Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
146 PM CDT Sat Apr 18 2026

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

.KEY MESSAGES...

- Scattered showers across South-Central Texas through Sunday
  morning, mostly light but with a few isolated thunderstorms
  mainly late afternoon today into the overnight hours.

- Gusty conditions will gradually lessen tonight.

- Cool weather continues into mid-week with moderate chances for
  rain through Wednesday.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 143 PM CDT Sat Apr 18 2026

A strong mid-April cold front has now swept across the entirety of
South-Central Texas, with temperatures cooling substantially on a
breezy north wind. Most have avoided measurable precip so far, but
areas will start to fill in with mostly light stratiform showers
today. We expect to see an uptick in convective activity with some
lightning in the late afternoon into the evening as mid-level ascent
ripples north to south through the area. A stronger storm or two
could be capable of producing some small hail as temperatures aloft
cool, but most of these deeper storms will be non-severe and mainly
pose an intermittent lightning risk to outdoor activities with
that risk peaking in the evening and early part of the night. The
area of showers and storms will gradually ease tonight with most
activity clearing out by sunrise Sunday. Overall rainfall amounts
will tend to be light relative to coverage given the high-based,
cooler nature of the rains... from a few hundredths of an inch to
about a quarter inch for most, and some isolated pockets of a 1/2
to 1 inch. Those marginally higher amounts are more likely over
the Coastal Plains.

Temperatures will continue to fall throughout the day into the
night. Residual post-frontal cloudiness will prevent more aggressive
cooling, but lows tonight should settle into the mid-40s to low-50s
with the coldest temperatures in the northern Hill Country and north
of the Austin area. Winds will gradually ease through the night with
gusts dropping below 25 mph for most, but it won't be until Sunday
afternoon that the enhanced post-frontal winds settle down more
fully.

Sunday is shaping up to be a tale of two halves of the region. For
areas generally north of I-10 or east of I-37, the day trends
sunnier and drier, allowing highs to reach the low 70s. To the west
and south across the Rio Grande Plains, a resurgent flow of
southerly winds aloft forces mid-level moisture back into the area.
This will keep an overcast in place along with light showers and
sprinkles, with a low chance of some rumbles of thunder. Those
clouds will also keep temperatures along the Rio Grande in the upper
50s to mid 60s Sunday afternoon. The area of light rains should inch
closer to the US-281 and I-35 corridors Sunday evening and
overnight. Lows Sunday night into Monday morning are forecast to be
in the 50s throughout South-Central Texas.

&&

.LONG TERM...
(Monday through next Saturday)
Issued at 143 PM CDT Sat Apr 18 2026

Despite the presence of a broader upper-level ridge moving over
Texas during the first half of the upcoming workweek, a mid-level
shortwave disturbance is forecast to slowly drift out of Mexico on
Monday before slowly making its way about Texas through Wednesday.
This keeps rain chances in the area during the first half of the
week. The best chances are probably on Tuesday, when the disturbance
is most favorably positioned to drag moisture across the region.
Chances for rain are most favored in South Texas and along the
Coastal Plains, especially if a coastal low or trough materializes
as indicated in the synoptic global models, though the latest
ensembles carry chances for rain across most of South-Central Texas
Monday and Tuesday with activity limited to mainly east of the I-35
corridor on Wednesday. The return of southerly winds at the surface
on Tuesday should help increase low-level instability, opening up
the potential for thunderstorms and a heavier rain.

Temperatures will be slow to warm up during the week with the
continued rain chances and cloudiness, staying well below average
Monday and Tuesday. Del Rio may see a few daily record cool high
temperatures with afternoon temperatures staying as much as 25
degrees below average. These cool anomalies aren't as dramatic to
the east, but are still 10-15 degrees below late-April norms. As
conditions start to clear up west-to-east on Wednesday with warmer
air aloft, temperatures should return to seasonably warm levels with
highs in the 80s and lows in the 60s. A pair of troughs over the
Rockies and Intermountain West late in the week may influence
conditions over our area Thursday to Saturday, possibly with some
dryline-related thunderstorm activity. However, those disturbances
won't reach the western US coast until midweek.

&&

.AVIATION...
(18Z TAFS)
Issued at 1217 PM CDT Sat Apr 18 2026

A FROPA occurred over the last couple hours and will keep winds
elevated through the next 12 hours or so before winds start to
relax after midnight tonight. The latest trends for thunderstorms
have shifted towards the evening hours and thus, have moved
PROB30s in that direction per the HREF suite. HREF mean composite
reflectivity focuses on SAT/SSF/AUS between 00Z and 06Z so have
used PROB30s for VIS and -TSRA restrictions accordingly. VFR
ceilings should return at all sites at least late afternoon
through the overnight, with a brief period of MVFR at SAT and SSF
tomorrow morning before sunrise.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              52  75  55  70 /  60   0  20  50
Austin Bergstrom Intl Airport  52  74  54  68 /  60   0  20  50
New Braunfels Muni Airport     52  73  54  68 /  70  10  30  60
Burnet Muni Airport            48  72  53  66 /  30   0  20  50
Del Rio Intl Airport           56  66  54  64 /  30  30  40  40
Georgetown Muni Airport        48  73  54  67 /  50   0  20  40
Hondo Muni Airport             53  67  53  62 /  70  10  50  60
San Marcos Muni Airport        52  73  55  67 /  70  10  30  60
La Grange - Fayette Regional   53  74  55  72 /  70  10  10  40
San Antonio Intl Airport       53  71  55  66 /  80  10  40  70
Stinson Muni Airport           54  70  56  66 /  80  10  40  70

&&

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

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

Special Weather Statement
National Weather Service Austin/San Antonio TX
542 PM CDT Sat Apr 18 2026

TXZ173-182315-
Williamson TX-
542 PM CDT Sat Apr 18 2026

...A strong thunderstorm will impact portions of central Williamson
County through 615 PM CDT...

At 542 PM CDT, Doppler radar was tracking a strong thunderstorm over
Georgetown Dam, or over Georgetown, moving northeast at 40 mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Round Rock, Georgetown, Granger, Serenada, Leander, Bartlett, Liberty
Hill, Jarrell, Florence, Weir, Georgetown Dam, Sun City, Andice,
Theon, Walburg, Schwertner, and Jonah.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3087 9762 3074 9727 3054 9775 3073 9795
      3089 9771
TIME...MOT...LOC 2242Z 239DEG 36KT 3064 9772

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

MO

Special Weather Statement
National Weather Service Austin/San Antonio TX
546 PM CDT Sat Apr 18 2026

TXZ171-182345-
Llano TX-
546 PM CDT Sat Apr 18 2026

...A strong thunderstorm will impact portions of northern Llano
County through 645 PM CDT...

At 546 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Mason, moving northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Llano, Castell, Field Creek, Baby Head, Lone Grove, Stolz, Bluffton,
and Valley Spring.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3078 9843 3064 9896 3092 9896 3092 9850
TIME...MOT...LOC 2246Z 240DEG 32KT 3066 9931

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

MO

Special Weather Statement
National Weather Service Austin/San Antonio TX
551 PM CDT Sat Apr 18 2026

TXZ187-189>191-204>206-182345-
Comal TX-Bexar TX-Blanco TX-Medina TX-Hays TX-Bandera TX-Kendall TX-
551 PM CDT Sat Apr 18 2026

...A strong thunderstorm will impact portions of eastern Medina,
southeastern Bandera, southwestern Hays, south central Blanco,
southeastern Kendall, northwestern Bexar and Comal Counties through
645 PM CDT...

At 551 PM CDT, Doppler radar was tracking a strong thunderstorm over
Cross Mountain, or 10 miles south of Boerne, moving northeast at 25
mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
San Antonio, New Braunfels, San Marcos, Boerne, Wimberley, Canyon
Lake Dam, Canyon Lake, Helotes, Fair Oaks Ranch, Bulverde, Shavano
Park, Cross Mountain, Woodcreek, Guadalupe River State Park, Smithson
Valley, Bandera Falls, The Dominion, Kreutzberg, Spring Branch, and
Government Canyon State Natural Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 2985 9789 2979 9796 2950 9881 2967 9899
      3015 9821
TIME...MOT...LOC 2251Z 237DEG 23KT 2964 9869

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

MO

Special Weather Statement
National Weather Service Austin/San Antonio TX
721 PM CDT Sat Apr 18 2026

TXZ173-191-192-190100-
Williamson TX-Hays TX-Travis TX-
721 PM CDT Sat Apr 18 2026

...A strong thunderstorm will impact portions of southwestern
Williamson, northwestern Hays and central Travis Counties through 800
PM CDT...

At 720 PM CDT, Doppler radar was tracking a strong thunderstorm over
Bee Cave, or 9 miles northeast of Dripping Springs, moving northeast
at 45 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Austin, Round Rock, Cedar Park, Georgetown, Pflugerville, Taylor,
Dripping Springs, Anderson Mill, Serenada, Windemere, Leander, Hutto,
Lakeway, Lago Vista, Bee Cave, West Lake Hills, Hudson Bend, The
Hills, Liberty Hill, and Rollingwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3071 9749 3051 9739 3005 9804 3020 9823
      3023 9822 3074 9786
TIME...MOT...LOC 0020Z 218DEG 39KT 3031 9797

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

MO