3 flash flood, 1 thunderstorm wind, as filed by the National Weather Service.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Austin/San Antonio, TX wrote its last area forecast discussion before the first event at Aug 22, 8:00 PM CST, 22 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 900 PM CDT SUN AUG 22 2004 .UPDATE...HEAVY RAIN NOW FOCUSED ALONG BEXAR MEDINA COUNTY LINE NORTH INTO EASTERN BANDERA AND KENDALL COUNTIES. HOT POCKET OF AIR TO OUR SOUTH AND SOUTHWEST BEING ADVECTED NORTHWARD (BY GOOD LOW LEVEL SOUTHERLY FLOW) INTO COOL THUNDERSTORM OUTFLOW..THUS CREATING A PSUEDO-COLD FRONTAL BOUNDARY WHICH IS HELPING TO MAINTAIN THESE STORMS. NEW FORECASTS HANDLE THIS WITH HEAVY RAINS. && .PREV DISCUSSION... SCATTERED SHRA/TSRA DRIFTING NWD ACRS THE WESTERN SXNS OF CNTRL TX AHEAD OF A S/W TROF SLOWLY LIFTING OUT OF MEXICO...WHILE SCT TO NUMEROUS SHRA/TSRA WERE SPREADING NWD ACRS THE EAST. STORMS WILL DIMINISH SOME THIS EVENING...BUT WILL CONT WITH LOW CHC POPS IN THE OVERNIGHT HOURS AHEAD OF THE S/W TROF. WILL SEE DIMINISHING POPS DURING THE DAY MONDAY ESPECIALLY IN THE WEST WITH THE TROF MOVG EWD AND EXCEPT FOR ISOLD-WDLY SCT SHRA/TSRA IN THE EAST MONDAY EVENING. BY MON EVENING THRU TUESDAY THE UPR RDG TO DOMINATE WITH WARMER HUMID CONDS PREVAILING. ON WEDNESDAY S/W ENERGY ENTERING SW TX COULD PRODUCE SCT CONVECTION IN THE NWRN CWA ON THE PERIPHERY OF THE RDG BY THE AFTN AND EVENING. FOR THE LATER PART OF THE WEEK INTO THE WEEKEND IT APPEARS S TX WILL CONTINUE TO BE ON THE EDGE OF THE RIDGE WITH PSBL S/W ENERGY LIFTING OUT OF MEXICO/W TX THAT COULD RESULT IN CONVECTION MOVG INTO THE NW CWA EACH AFTN AND EVENING. FOR NOW HOWEVER WILL FORECAST GENERALLY AS IS WITH CLIMO SEA-BREEZE POPS MAINLY IN THE EAST. && .EWX WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WARNING FOR BEXAR AND MEDINA COUNTIES TIL 1045 PM. && 02/13
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 539 AM CDT SUN AUG 22 2004 TXZ171>173-183>194-202>209-217>225-228-231030- ATASCOSA-BANDERA-BASTROP-BEXAR-BLANCO-BURNET-CALDWELL-COMAL-DEWITT- DIMMIT-EDWARDS-FAYETTE-FRIO-GILLESPIE-GONZALES-GUADALUPE-HAYS-KARNES- KENDALL-KERR-KINNEY-LAVACA-LEE-LLANO-MAVERICK-MEDINA-REAL-TRAVIS- UVALDE-VAL VERDE-WILLIAMSON-WILSON-ZAVALA- 539 AM CDT SUN AUG 22 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS. .DAY ONE...TODAY. SCATTERED THUNDERSTORMS CAN BE EXPECTED ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS. THE PRIMARY THREATS ARE LOCALLY HEAVY RAINFALL AND LIGHTNING STRIKES. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. THERE ARE ONLY SLIGHT CHANCES OF THUNDERSTORMS. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.
The Austin/San Antonio radar (KEWX), 69 km away, was scanning. The volume nearest the first event began at 02:19 UTC.
3 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Severe thunderstorm winds blew down power lines in the western part of San Antonio.
Heavy rainfall over saturated soils caused flash flooding from late on the night of August 21 into the next morning over eastern Medina County. Rain totals were between 1 and 2 inches over the east half of the county with the maximum amounts near 4 inches along US90 just west of the Bexar County line. Numerous roads were closed by the flash flooding, including FM471 near LaCoste.
Flash Flooding from a 2 inch rainfall in northwest San Antonio closed portions of Callaghan Road near Woodside.
Thunderstorms continued to rain heavily from the evening of August 22 through the morning of August 23 over Frio County. Widespread flash flooding resulted from the storms as the whole county received from 2 to 3 inches of rain. The heaviest rain fell over the northern half of the county where rain totals averaged between 5 and 6 inches. The highest rain total of 13 inches was received from just north of Frio Town. The Frio County Sheriff's Department reported numerous rescues on SH85 and FM117 around 0700 CST near Dilley. Rainfall was so heavy that water covered portions of IH-35 from south of Pearsall well into LaSalle County. This unprecedented level of flooding kept the interstate highway closed for 12 hours.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2004Every state in 2004This day in weather historyWarnings in Texas, August 2004
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5420605, 5420606, 5420607, 5420608.