Several days of heavy rain, along with major to record flooding the previous week, led to more flooding across portions of the western South Dakota plains and foothills of the Black Hills. The period of wet weather culminated with heavy rain and thunderstorms over the Rapid City area during the afternoon and evening of May 31, which led to widespread flooded roads.
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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 episode as NWS UNR wrote it up.
Several days of heavy rain, along with major to record flooding the previous week, led to more flooding across portions of the western South Dakota plains and foothills of the Black Hills. The period of wet weather culminated with heavy rain and thunderstorms over the Rapid City area during the afternoon and evening of May 31, which led to widespread flooded roads.
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 May 27, 4:09 AM MST, 1 hour 46 minutes earlier.
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
509 AM MDT Mon May 27 2019
.DISCUSSION...(Today Through Sunday)
Issued at 305 AM MDT Mon May 27 2019
Current surface map shows area of low pressure in northeast
Nebraska with cold front across northern Nebraska. A few
showers/thunderstorms linger across northeast Wyoming and south
central South Dakota, with drizzle expanding in upslope flow
around the Black Hills. Cloudy/cool day across the forecast area
today, with front stalled across Nebraska. Focus for precipitation
through first half of the day will be upslope drizzle/showers.
Coverage of showers will expand across the area this afternoon as
next impulse ejects from southwest upper low. A few thunderstorms
possible across the southern portions of the forecast area with
with elevated CAPE. Surface based instability remains south of
the forecast area...along with threat of severe thunderstorms.
Upper low moves across the central Rockies tonight...then into
Western Nebraska Tuesday. GFS/ECMWF/GEM continue with slower
movement of upper low...with it located over northeast
Nebraska/Southeast South Dakota on Wednesday. NAM is located even
further west on Wednesday...with upper low over western South
Dakota. Coverage/intensity of rain will increase tonight...aided
by deep/moist upslope flow. Additional rainfall of 1-2" expected
along and south of Interstate 90...with locally heavier amounts
around the Black Hills.
Weak upper high settles in over the area Thursday/Friday with
warmer temperatures. May be a few thunderstorms around the Black
Hills and south central South Dakota, but most locations will get
a much needed period of dry weather. Pattern becomes more active
for the weekend with increasing threat of thunderstorms.
&&
.AVIATION...(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 503 AM MDT Mon May 27 2019
Widespread MVFR/IFR conditions are expected today and tonight in
fog, drizzle, showers, and thunderstorms. The lowest
ceilings/visibilities will be around the Black Hills area.
Easterly winds will remain breezy through tonight.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Flood Watch through late Tuesday night for SDZ012>014-024>032-
041>044-046-047-049-072>074.
WY...Flood Watch from noon MDT today through Tuesday afternoon for
WYZ054>058-071.
&&
DISCUSSION...7
AVIATION...PojorlieThe Rapid City radar (KUDX), 71 km away, was scanning. The volume nearest the first event began at 12:57 UTC.
10 flood, 2 flash flood. Local standard time, as filed.
Minor flooding of agricultural land occurred along the White River south of Kadoka. The river crested at 14.25 feet (flood stage of 13 feet) on May 29.
Minor flooding of agricultural land occurred along the White River around the SD Highway 47 bridge south of Reliance. The river crested a few feet over flood stage (15 feet) at 19.0 feet on May 29, with a peak flow around 30,600 cfs.
Minor flooding of agricultural land occurred along the White River around the US Highway 83 bridge north of the town of White River. The river crested just over flood stage (14 feet) at 14.92 feet on May 28, with a peak flow around 18,100 cfs.
Runoff from heavy rain over northwestern Nebraska caused minor to moderate flooding of the White River from the Nebraska state line to the Badlands.
Runoff from heavy rain flooded creeks and inundated roads. Water covered part of Winter Street/US Highway 16A in Keystone. Water was reported over Old Hill City Road near Keystone, Grizzly Gulch Road, Mountain Park Road, Spring Creek Road, Lower Spring Creek Road, Rockwood Road, South Valley Drive, Orchard Lane, Reservoir Road, Green Valley Drive, Lamb Road, Anderson Road, Antelope Creek Road three miles south of SD Highway 44, Neva Way, 143rd Avenue, 156th Street south of highway 14-16, and 159th Street.
Runoff from heavy rain flooded creeks and inundated roads. Flooding was reported on US Highway 16A near the Coolidge General Store and the Wildlife Loop Road in Custer State Park. Battle Creek covered several roads west of Hermosa. Spring Creek covered portions of Lower Spring Creek Road east of Hermosa. Cottonwood Creek overtopped Cottonwood Cutoff Road east of Buffalo Gap.
Releases from Angostura Dam, combined with runoff from heavy rain, caused moderate flooding of agricultural land along the Cheyenne River. The river crested over flood stage (14 feet) at 19.86 feet on May 30, with a peak flow around 34,100 cfs.
Releases from Angostura Dam, combined with runoff from heavy rain, caused moderate flooding of agricultural land along the Cheyenne River. The river crested over flood stage (14 feet) at 19.86 feet on May 30, with a peak flow around 34,100 cfs.
Runoff from heavy rain on already saturated ground caused flash flooding on the north and east sides of Rapid City. At least three people had to be rescued after driving into flood waters, including one where a culvert washed out on Nike Road just east of Haines Avenue and north of Country Road.
Runoff from heavy rain on saturated ground caused flash flooding in the Sturgis, Fort Meade, and Pleasant Valley areas for the second time in a week. Several roads across Bear Butte Creek were covered with water or were washed out; including 7th Street, 9th Street, 15th Street, Raccoon Road, Sly Street, and SD Highway 34, Fort Meade Way, and Pleasant Valley Drive.
As the flash flooding ended, flooding continued on Box Elder Creek north of Rapid City to Box Elder. Water flooded portions of County Road, north Elk Vale Road, Radar Hill Road, south Ellsworth Road south of Highway 14-16, and Line Road. Evacuations occurred on Line Road as water surrounded several mobile homes.
As the flash flooding ended, flooding continued on Box Elder Creek north of Rapid City. Water covered Peaceful Pines Road near Erickson Ranch Road, portions of Country Road, parts of Dyess Avenue, and north Elk Vale Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2019Every state in 2019This day in weather historyWarnings in South Dakota, May 2019
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: 831883, 831887, 831886, 831881, 831897, 831901, 831888, 831890, 831903, 831893, 831904, 831907.