Flash Flood, Custer
- When
- August 17, 7:15 PM MST to August 18, 4:00 AM MST
- Where
- Custer County, 10 mi N of Dewey
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 43.678, -103.451 (the zone’s center; the record gives no point)
Flash Flood in South Dakota, August 17 to 18, 2003
Slow moving thunderstorms produced 3 to 5 inches of rain over southwestern Custer County and caused flooding in the Tepee Canyon and Hell Canyon areas northeast of Dewey. Water was reported to be 2 feet deep on county road 769 in Hell Canyon during the evening.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
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.
What happened
The episode as NWS UNR wrote it up.
Slow moving thunderstorms produced 3 to 5 inches of rain over southwestern Custer County and caused flooding in the Tepee Canyon and Hell Canyon areas northeast of Dewey. Water was reported to be 2 feet deep on county road 769 in Hell Canyon during the evening. County roads 270, 272, and 769 were closed overnight. No property damage was reported in the area.
What forecasters said that day
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 Rapid City, SD wrote its last area forecast discussion before the first event at Aug 17, 6:20 PM MST, 55 minutes earlier.
Area forecast discussion, Aug 17, 6:20 PM MST, 55 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 720 PM MDT SUN AUG 17 2003 HAVE UPDATED ZONES TO INCREASE PCPN COVERAGE ACROSS AREA. HAVE ALSO UPDATED WINDS AS THEY HAVE SHIFTED TO NW OVR ALL BUT FAR S-CENT SD. .UNR...NONE.
Hazardous weather outlook, Aug 17, 5:30 AM MST, 13 hours 45 minutes before
SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058- 071-181230- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RAPID CITY SD 630 AM MDT SUN AUG 17 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND PERSIST THROUGH THE EVENING...MORE NUMEROUS OVER NORTHEASTERN WYOMING AND FAR NORTHWESTERN SOUTH DAKOTA. THESE STORMS ARE NOT EXPECTED TO BECOME SEVERE...HOWEVER STRONGER STORMS MAY PRODUCE GUSTY WINDS AND SMALL HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE MONDAY THROUGH TUESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.
In the hours before
Local storm report, Aug 17, 7:00 PM MST, 15 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
800 PM MDT SUN AUG 17 2003
TIME(MDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0635 PM 1 E ARGYLE SD 1 INCH HAIL
08/17/03 CUSTER REPORTED BY PUBLIC.The radar
The national radar mosaic for the moment the first event began.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Heat in Missouri, August 17 to 23, 2003
- Flash Flooding and Hail in North Carolina, August 17, 2003
- Tropical Storm in Guam, August 17, 2003
- Lightning Strike in New Jersey, August 17, 2003
- Hail and Damaging Winds in Virginia, August 17, 2003
- Damaging Wind in Kentucky, August 17, 2003
- Flash Flood and Hail in Virginia, August 17, 2003
- Damaging Wind and Lightning Strike in South Carolina, August 17, 2003
- Hail and Damaging Wind in Virginia, August 17, 2003
- Flash Flooding in New York, August 17, 2003
- Heat in Kansas, August 17 to 23, 2003
- Hail and Damaging Winds in North Carolina, August 17, 2003
More
Every storm in South Dakota in 2003Every state in 2003This day in weather historyWarnings in South Dakota, August 2003
Sources
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: 5378095.