452
FXUS64 KEWX 210000
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
700 PM CDT WED MAY 20 2026
..NEW AVIATION
KEY MESSAGES
- STORMS WITH POTENTIAL FOR LOCALLY HEAVY RAIN AND SEVERE WEATHER
LATE TONIGHT WITH THE HIGHEST RISKS NEAR THE RIO GRANDE.
- ACTIVE WEATHER PATTERN CONTINUES THROUGH THE UPCOMING MEMORIAL
HOLIDAY WEEKEND. MULTIPLE ROUNDS OF STORMS WITH HEAVY RAIN COULD
LEAD TO LOCALIZED FLOODING.
- WET PATTERN LIKELY TO CONTINUE INTO NEXT WEEK.
SHORT TERM
(TODAY THROUGH THURSDAY)
ISSUED AT 147 AM CDT WED MAY 20 2026
LAST NIGHT'S STORMS EXHAUSTED A SUBSTANTIAL PORTION OF AVAILABLE
INSTABILITY IN THE ATMOSPHERE. THIS HAS MUTED ACTIVITY FOR MOST OF
SOUTH-CENTRAL TEXAS TODAY ASIDE FROM SOME ISOLATED STORM ACTIVITY
ALONG THE RIO GRANDE, BUT THE SURFACE BOUNDARY LAYER IS EXPECTED TO
RECOVER FURTHER WITH ADDITIONAL LOW-LEVEL MOISTURE RETURNING FROM
THE CORPUS CHRISTI AREA TOWARDS THE RIO GRANDE AND UP INTO WEST
TEXAS, RUNNING UP AGAINST THE DRY LINE THERE AND OVER MEXICO. AN
IMPULSE OF MID- LEVEL ENERGY SHOULD OVERLAP WITH THE MOISTURE AND
DRY LINE TONIGHT, LEADING TO THE DEVELOPMENT OF STORMS NEAR THE
RIO GRANDE AND WEST TEXAS IN THE EVENING WHICH MAY ORGANIZE INTO
AN EASTWARD-ADVANCING BROKEN LINE OF STORMS DURING THE OVERNIGHT
HOURS INTO EARLY THURSDAY MORNING GIVEN THE DISTINCTLY MERIDIONAL
MID-LEVEL FLOW.
SOME INITIAL ISOLATED STORMS COULD DEVELOP CLOSER TO THE RIO GRANDE
AND EDWARDS PLATEAU CLOSER TO SUNSET, BUT THE BULK OF THE ACTIVITY
AND THE POTENTIAL LINE-TO-BE ARE GENERALLY FAVORED AFTER MIDNIGHT
AND THIS IS REFLECTED IN HI-RES MODELS. SCATTERED STORMS SHOULD PUSH
ACROSS THE SOUTHERN EDWARDS PLATEAU, RIO GRANDE PLAINS AND HILL
COUNTRY LATE THIS EVENING INTO THE WEE HOURS OF THE MORNING,
POTENTIALLY REACHING THE I-35 CORRIDOR IN THE PRE-DAWN HOURS AND
THEN THE COASTAL PLAINS THURSDAY MORNING. INSTABILITY AND SHEAR ARE
NOT EXPECTED TO BE AS HIGH AS LAST NIGHT, SO IT'S SOMEWHAT UNCLEAR
HOW FAR EAST THESE STORMS WILL GET... THERE'S A DECENT CHANCE THEY
COULD BE RUNNING OUT OF STEAM AND PRODUCING MOSTLY STRATIFORM
LIGHT/MODERATE RAINS AS THEY MOVE OVER I-35 AND THE COASTAL PLAINS.
THE INITIAL ENVIRONMENT ALONG THE RIO GRANDE IS SUPPORTIVE OF SLOWER
STORM MOTIONS AND WOULD BE IN A >95TH PERCENTILE PRECIPITABLE WATER
ENVIRONMENT, SO A FEW SLOW-MOVING HEAVY DOWNPOURS CAPABLE OF
LOCALIZED FLASH FLOODING ARE POSSIBLE THIS EVENING AND TONIGHT
ESPECIALLY IF STORMS DEVELOP EARLY. THE MAIN LINE OF STORMS SHOULD
BE MOVING AT A DECENT CLIP EASTWARD, BUT WILL OVERLAP WITH THE AREAS
SATURATED BY LAST NIGHT'S STORMS. THIS COULD LEAD TO ISOLATED
FLOODING CONCERNS, PARTICULARLY IN URBAN AREAS, DESPITE GENERALLY
LOWER RAIN TOTALS OVERALL FARTHER EAST. A LEVEL 2 OF 4 (SLIGHT) RISK
OF EXCESSIVE RAIN CAPABLE OF FLASH FLOODING IS INDICATED BY THE WPC
FOR ALL OF SOUTH-CENTRAL TEXAS THROUGH THURSDAY MORNING. BROAD RAIN
AMOUNTS OF 0.5-1.5 INCHES WITH ISOLATED TOTALS IN THE 3-5 INCH RANGE
ARE POSSIBLE OVER THE RIO GRANDE PLAINS AND EDWARDS PLATEAU. AMOUNTS
GENERALLY LESSEN FARTHER EAST, WITH AREAL AMOUNTS IN THE 0.1-0.75
INCH RANGE AND ISOLATED POCKETS OF 1-3 INCHES POSSIBLE AS RAINS
MOVE TO THE I- 35 CORRIDOR AND POINTS EAST. THE SEVERE RISK WILL
BE HIGHER WITH THE INITIAL DEVELOPMENTS ALONG THE RIO GRANDE AND
EDWARDS PLATEAU WHERE SHEAR AND INSTABILITY ARE HIGHER, WITH
ISOLATED INSTANCES OF LARGE HAIL POSSIBLE WITH A TRANSITION TO
ISOLATED DAMAGING WIND AS THE LINE OF STORMS MATERIALIZES. GIVEN
THE LOWER ENERGY AVAILABLE FARTHER EAST, THE SEVERE THREAT TAPERS
OFF TOWARDS I-35, THOUGH FREQUENT LIGHTNING AND INTERMITTENT GUSTY
WINDS REMAIN POSSIBLE. A LEVEL 2 OF 5 (SLIGHT) RISK FOR SEVERE
WEATHER IS DEPICTED FOR THE DEL RIO, ROCKSPRINGS, BRACKETTVILLE,
AND EAGLE PASS AREAS, WITH A LEVEL 1 OF 5 (MARGINAL) RISK
EXTENDING TO JUST WEST OF A FREDERICKSBURG TO SAN ANTONIO TO
PLEASANTON LINE.
WITH TONIGHT'S LINE OF STORMS, WE'LL ONCE AGAIN REPEAT THE CYCLE OF
OVERNIGHT ACTION KEEPING DAYTIME ACTIVITY ON THE QUIETER SIDE ON
THURSDAY. CONDITIONS ARE NOT EXPECTED TO BE AS HUMID DURING THE DAY,
THOUGH COOLER MID-LEVEL TEMPERATURES AROUND THE CORE OF THE
AFOREMENTIONED IMPULSE OF MID-LEVEL ENERGY AND CONTINUED SOUTHERLY
FLOW OFF THE GULF COULD SUPPORT SOME ISOLATED TO SCATTERED
THUNDERSTORMS THURSDAY AFTERNOON AND EVENING, WITH THIS ARRANGEMENT
TENDING TO PRODUCE THE GREATEST CHANCES IN THE AUSTIN AREA, HILL
COUNTY, AND COASTAL PLAINS. WHILE THE HI-RES MODELS DISAGREE ON THE
PROSPECTS FOR ANOTHER ROUND OF AN ORGANIZED STORM CLUSTER DEVELOPING
NEAR THE RIO GRANDE LATER THURSDAY, THE PRESENCE OF YET ANOTHER MID-
LEVEL DISTURBANCE MOVING OVER THE REGION AROUND THAT TIME INDICATES
THAT THERE IS A WINDOW OF OPPORTUNITY FOR SOME CONVECTIVE COMPLEX
MOVING EAST ACROSS OUR ZONE LATE THURSDAY INTO FRIDAY MORNING. THE
POTENTIAL THERE WOULD PROBABLY BECOME CLEARER ONCE WE CAN DIAGNOSE
HOW TONIGHT'S LINE OF STORMS INTERACTS WITH THE ENVIRONMENT.
LONG TERM
(FRIDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 123 PM CDT WED MAY 20 2026
THE WET PATTERN IS LIKELY TO CONTINUE THROUGH AT LEAST THE MIDDLE OF
NEXT WEEK, AND POTENTIALLY THROUGH THE ENTIRETY OF NEXT WEEK AS
TROUGHING NEAR OUR AREA CONTINUES TO PROVIDE A FAVORABLE PATHWAY FOR
MOISTURE AND DISTURBANCES TO REPEATEDLY STREAM OVER TEXAS.
THERE IS A FAVORABLE WINDOW THIS WEEKEND FOR POTENTIALLY WIDESPREAD
RAINS WITH LOCALLY HEAVIER AMOUNTS. A PRONOUNCED TROUGH IS EXPECTED
TO SWING OUT OF THE BAJA CALIFORNIA SATURDAY AND MOVE ACROSS OUR
AREA DURING THE DAY INTO SUNDAY. WHILE THE SPECIFICS OF HOW THE
ACCOMPANYING RAIN MAY SET UP ARE FUZZY AT THE MOMENT, AMONG THE
VARIOUS DISTURBANCES IN THE FORECAST RANGE THIS ONE IS THE MOST WELL-
DEFINED IN THE UPPER-LEVELS OF THE TROPOSPHERE. CURRENTLY, THE
MEDIUM RANGE ENSEMBLE GUIDANCE IS WEIGHTED TOWARDS THE I-35 CORRIDOR
AND COASTAL PLAINS LATE SATURDAY TO EARLY SUNDAY, BUT EXPECT THAT
TIMING TO BE REFINED IN LATER FORECASTS.
RIDGING BUILDS OVER THE CENTRAL AND NORTHERN PLAINS EARLY NEXT WEEK,
WITH BOTH THE GEFS AND ENS ENSEMBLE SUITES IN AGREEMENT ON THIS
DEPICTION. THIS HOLDS THE TROUGH IN PLACE OVER TEXAS AND COULD
PROVIDE ADDITIONAL ROUNDS OF RAIN BETWEEN SUNDAY AND TUESDAY. WHILE
THE AVERAGE PLACEMENT OF THE TROUGH IN THE ENSEMBLES TENDS TO CYCLE
IN DRIER MID-LEVEL AIR OVER OUR AREA, IF THE STALLED POSITION IS
SLIGHTLY FARTHER WEST, IT COULD AMPLIFY RAIN AMOUNTS OVER SOUTH-
CENTRAL TEXAS.
TOWARDS THE MIDWEEK, BROADER TROUGHING REBUILDS OVER THE WESTERN US.
THIS ALLOWS THE STALLED TROUGH TO GET MOVING AGAIN, ONLY TO BE
REPLACED BY MORE SOUTHWESTERLY FLOW ALOFT, KEEPING THE DOOR OPEN FOR
MORE RAIN CHANCES. THUS, THE OVERALL FORECAST PICTURE IS
DEFINITIVELY WET AS WE START TO CLOSE OUT MAY. THE GRAND ENSEMBLE
(GEFS, ENS, AND GEPS COMBINED) HAS IMPRESSIVE MEAN RAINFALL AMOUNTS
ABOVE 3 INCHES ACROSS NEARLY ALL OF SOUTH-CENTRAL TEXAS THROUGH THE
MIDDLE OF NEXT WEEK, WHICH IS AN IMPRESSIVE AMOUNT FOR LOWER
RESOLUTION MEDIUM RANGE MODELS TO BE PROJECTING.
EACH ROUND OF RAINFALL WILL CONTINUE TO MOISTEN/SATURATE SOILS,
INCREASING THE POTENTIAL FOR RUNOFF WHICH MAY EVENTUALLY LEAD TO
FLASH FLOODING OR RIVER FLOODING. GIVEN THE DEPENDENCE ON WHERE EACH
ROUND OF STORMS MOVES ACROSS, PINPOINTING EXACT RAINFALL TOTALS IS
DIFFICULT THOUGH WE DO EXPECT MANY TO RECEIVE WIDESPREAD BENEFICIAL
RAINFALL. THOSE THAT SEE MULTIPLE STORMS REPEATEDLY TRACKING OVER
THEIR AREA COULD EVENTUALLY SEE FLOODING AND CANNOT RULE OUT A FLOOD
WATCH LATER IN THE WEEK OR WEEKEND. CONTINUE TO MONITOR THE FORECAST
AND ALWAYS HAVE A WAY TO RECEIVE WARNING INFORMATION.
AVIATION
(00Z TAFS)
ISSUED AT 639 PM CDT WED MAY 20 2026
SHORTWAVE ACTIVITY EMBEDDED IN BROAD SW FLOW PATTERN ALOFT OVER
THE MEXICAN PLATEAU WILL SUPPORT ROBUST CONVECTION OVER THE
MOUNTAINS THIS EVENING, BUT SHOULD REMAIN FAR AWAY FROM THE TAF
SITES FOR MUCH OF THE EVENING. BY AROUND 03Z SOME CONVECTIVE
ACTIVITY COULD ENCROACH UPON THE DRT VCNTY, BUT WE'LL GO THE
LATEST HRRR SUGGESTION AND TARGET A 4 HOUR WINDOW STARTING AT 4Z.
LATER IN THE OVERNIGHT, OR ROUGHLY AROUND THE TIME WE'D NORMALLY
SEE MVFR CIGS SHOW UP OVER I-35 THE ONSET OF CONVECTION IS PEGGED
FOR 09Z AND 10Z FOR SAN ANTONIO AND AUSTIN RESPECTIVELY. COVERAGE
SHOULD BE ABOUT 50-60 PERCENT SO THE CURRENT PROB30 GROUPS WILL
LIKELY BE UPGRADED AS THE POTENTIAL EVENT DRAWS CLOSER IN TIME.
SOME INTERMITTENT LOW CIGS ARE ADDED FOR LATE MORNING, BUT THE
SUBSIDENCE WAKE BEHIND THE CONVECTION COULD BE ENOUGH TO KEEP THAT
FROM HAPPENING. IN GENERAL, WE'D ASSUME THAT EACH SITE MAY CATCH A
BRIEF GLIMPSE OF MVFR BEFORE THE BUOYANT TROPICAL AIR MIXES THE
CEILINGS HIGHER TOWARD MIDDAY.
PRELIMINARY POINT TEMPS/POPS
AUSTIN CAMP MABRY 70 80 69 86 / 60 60 50 30
AUSTIN BERGSTROM INTL AIRPORT 70 80 69 86 / 60 60 50 40
NEW BRAUNFELS MUNI AIRPORT 69 81 68 86 / 60 60 40 40
BURNET MUNI AIRPORT 67 77 66 84 / 60 60 40 20
DEL RIO INTL AIRPORT 67 84 68 88 / 90 20 10 20
GEORGETOWN MUNI AIRPORT 68 78 67 85 / 60 60 50 30
HONDO MUNI AIRPORT 68 81 67 85 / 90 40 30 10
SAN MARCOS MUNI AIRPORT 70 81 69 86 / 60 60 40 40
LA GRANGE - FAYETTE REGIONAL 71 80 70 85 / 60 70 50 50
SAN ANTONIO INTL AIRPORT 70 82 70 86 / 70 50 40 30
STINSON MUNI AIRPORT 70 82 70 87 / 70 50 40 20
EWX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...TRAN
LONG TERM....TRAN
AVIATION...18
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page