Flash Flood Warning 48, NWS Austin/San Antonio, TX

074 
WGUS74 KEWX 200841
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
341 AM CDT Sat Jun 20 2026

TXC029-091-259-201100-
/O.CON.KEWX.FF.W.0048.000000T0000Z-260620T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bexar TX-Comal TX-Kendall TX-
341 AM CDT Sat Jun 20 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM CDT EARLY THIS 
MORNING FOR NORTHWESTERN BEXAR, WEST CENTRAL COMAL AND SOUTH CENTRAL 
KENDALL COUNTIES...

At 341 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 3 inches of rain have 
fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  San Antonio, Boerne, Helotes, Fair Oaks Ranch, Bulverde, Shavano 
  Park, Hollywood Park, Cross Mountain, Leon Springs, The Dominion, 
  Timberwood Park, Bergheim, Government Canyon State Natural Area, 
  Kronkosky State Natural Area, Hill Country Village, Grey Forest, 
  Scenic Oaks, Fiesta Texas, Cascade Caverns and Specht Store.

Light to moderate rains continue to fall over the warned area, with 
an additional 1/4 to 1/2 inch possible through 6 AM. This additional 
rain could maintain elevated flows on area creeks and streams and 
also further add to the flooding of poor drainage areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 2975 9885 2984 9860 2982 9841 2960 9846
      2953 9881 2961 9881 2964 9881 2969 9881
      2970 9880 2972 9878

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MO

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1258 AM CDT Sat Jun 20 2026

...New AVIATION...

.KEY MESSAGES...

- Concern for locally heavy rain with isolated instances of flash
  flooding during the overnight into this morning; greatest area
  of concern along and south of the I-10/US Highway 90 corridor.

- Lingering of low to medium (20-40%) rain and storm chances for
  this afternoon through Sunday morning before a drier pattern
  establishes.

- Summer heat featuring elevated heat indices through next week.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 1035 PM CDT Fri Jun 19 2026

A lull in activity occurred through the evening hours behind the
outflow/frontal boundary that had advanced across the region earlier
today. That boundary had sparked some isolated to scattered rain and
storms but also some significant relief to the hazardous heat we had
experienced recently. Several short term guidance members show an
increase in rain and storm coverage into and through the overnight
hours tonight, with the greatest concentration generally near and to
the south of the I-10/US HWY 90 corridor. This could be associated
with or at least an extension of a storm complex that has developed
just to the west of the Rio Grande across Mexico down by Laredo. The
activity may also connect with the nearby boundary, sparking
additional activity. Rainfall rates with the overnight activity
could become quite heavy with rates in excess of 2-3 inches per hour
at times. Given this potential, isolated instances of flash flooding
will remain possible. Activity could push south or southeastward
into the CRP CWA near or not too long after sunrise. I'll continue
to note that the confidence on the rain and storms remains low given
the chaotic nature of the recent storm complexes within the weak
steering flow aloft.

Later today remains dependent on how the atmosphere recovers from
the possible overnight into early morning activity. Overall, heat
indices should remain below heat advisory criteria but could reach
in excess of 100 degrees for locations along the I-35 corridor, and
within the Coastal and Rio Grande Plains. Enough instability could
establish with daytime heating where isolated to scattered shower
and storm activity will be possible from the afternoon into the
night, mainly to the east of the Rio Grande. Activity may linger
into Sunday morning.

Sunday afternoon then looks to start the drying trend regarding the
area rain chances and this continues onward into the long term as
the long term forecast discussion below highlights. Mid-level
ridging remains in control to our west along the Arizona/New Mexico
border and Northern Mexico. It expands a bit father east into West
Texas Sunday and this would kick the broad troughiness that is over
the region currently, to the east. Heat then returns to being the
primary story with the afternoon highs in the mid to upper 90s and
heat indices peaking between 100 to 110 degrees. We'll monitor area
extent of the heat indices near or above 108 as we get closer in
time to evaluate a possible issuance of a Heat Advisory.

&&

.LONG TERM...
(Monday through next Saturday)
Issued at 1035 PM CDT Fri Jun 19 2026

Mid-level ridging remains anchored through much of the long term
period to our west across Northern Mexico to near or just south of
the Arizona/New Mexico border. The eastern periphery of the ridge
will continue to push into West Texas. For South-Central Texas,
we'll remain under a northerly flow aloft. The forecast will remain
mostly rain free but with the northerly flow, we'll have to keep a
close eye on any convection to the north that would try to slide
southward. For now, majority of the guidance favors keeping the
activity across Oklahoma/Arkansas with some activity reaching
southward into the northern half of Texas. Otherwise, a persistent
south-southeasterly low-level flow will keep hot and humid weather
in place with elevated heat indices. Afternoon highs generally
remain in the mid 90s while the overnight lows fall into the mid
to upper 70s.

&&

.AVIATION...
(06Z TAFS)
Issued at 1251 AM CDT Sat Jun 20 2026

Backbuilding convection is occurring over N Bexar County and will
present a lightning threat for SAT and SSF for much of the pre-
dawn hours. A smaller pocket of convection could impact AUS
through around 07Z. Recent runs of the HRRR suggest DRT is out of
the area of convective focus, so we've opted out of putting any
convective elements there. Assuming the convection areas wane
closer to daybreak, will assume the normal diurnal trend for MVFR
CIGs take over in an above normal rainfall pattern for June
keeping most hours cloudy in the 06Z to 18Z time window.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              91  77  95  78 /  30  10  20   0
Austin Bergstrom Intl Airport  91  77  94  79 /  30  10  20   0
New Braunfels Muni Airport     91  77  94  77 /  30  20  20   0
Burnet Muni Airport            89  76  93  77 /  30  10  10   0
Del Rio Intl Airport           93  77  96  79 /  10   0   0   0
Georgetown Muni Airport        90  77  94  78 /  40  10  10   0
Hondo Muni Airport             91  76  94  77 /  30  20  20   0
San Marcos Muni Airport        90  77  94  77 /  30  20  20   0
La Grange - Fayette Regional   91  78  93  79 /  50  20  20   0
San Antonio Intl Airport       90  78  93  78 /  30  30  20   0
Stinson Muni Airport           91  78  93  78 /  30  30  20   0

&&

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

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

Special Weather Statement
National Weather Service Austin/San Antonio TX
934 PM CDT Fri Jun 19 2026

TXZ218-219-228-200315-
Frio TX-Dimmit TX-Zavala TX-
934 PM CDT Fri Jun 19 2026

...A strong thunderstorm will impact portions of eastern Dimmit,
southeastern Zavala and southwestern Frio Counties through 1015 PM
CDT...

At 934 PM CDT, Doppler radar was tracking a strong thunderstorm near
Light, or 12 miles southeast of Big Wells, moving northeast at 35
mph.

HAZARD...Wind gusts up to 50 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...
Dilley, Big Wells, Brundage, Chaparral Wildlife Management Area,
Light, Hilltop, Divot, Catarina, and Las Vegas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 2820 9962 2866 9977 2879 9916 2865 9904
      2864 9939 2821 9940
TIME...MOT...LOC 0234Z 233DEG 29KT 2841 9949

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

17

Special Weather Statement
National Weather Service Austin/San Antonio TX
1014 PM CDT Fri Jun 19 2026

TXZ218-219-228-200400-
Frio TX-Dimmit TX-Zavala TX-
1014 PM CDT Fri Jun 19 2026

...A strong thunderstorm will impact portions of northeastern Dimmit,
southeastern Zavala and southwestern Frio Counties through 1100 PM
CDT...

At 1014 PM CDT, Doppler radar was tracking a strong thunderstorm over
Las Vegas, or near Big Wells, moving north at 15 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...
Big Wells, Brundage, Chaparral Wildlife Management Area, Light, Loma
Vista, Las Vegas, and Catarina.

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.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2833 9959 2866 9977 2883 9955 2876 9926
      2864 9929 2864 9939 2827 9940
TIME...MOT...LOC 0314Z 196DEG 13KT 2855 9949

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

17

Special Weather Statement
National Weather Service Austin/San Antonio TX
1056 PM CDT Fri Jun 19 2026

TXZ203-218-200500-
Uvalde TX-Zavala TX-
1056 PM CDT Fri Jun 19 2026

...Strong thunderstorms will impact portions of southwestern Uvalde
and central Zavala Counties through MIDNIGHT CDT...

At 1056 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Blewett to 6 miles east of La Pryor to
Loma Vista. Movement was north at 15 mph.

HAZARD...Wind gusts up to 50 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...
Uvalde, La Pryor, Batesville, Knippa, Uvalde Estates, Laguna, Dabney,
Montell, Blewett, Cline, Loma Vista, and Washer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2910 10010 2962 10011 2962 10006 2940 9967
      2899 9941 2864 9953 2864 9962
TIME...MOT...LOC 0356Z 186DEG 15KT 2918 9998 2896 9975 2875 9962

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

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