South Dakota, 2011

Hail in South Dakota, April 21, 2011

April 21, 2011 · NWS UNR · 3 events in 1 county or zone

A thunderstorm developed over the Black Hills west of Rapid City and moved over town during the early evening. Hail to the size of pennies accumulated several inches deep in a swath from downtown Rapid City to Rapid Valley.

Where it happened

Every event with a place to put it. 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

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
3

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.

A thunderstorm developed over the Black Hills west of Rapid City and moved over town during the early evening. Hail to the size of pennies accumulated several inches deep in a swath from downtown Rapid City to Rapid Valley.

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 Apr 21, 1:30 PM MST, 4 hours 45 minutes earlier.

Area forecast discussion, Apr 21, 1:30 PM MST, 4 hours 45 minutes before
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Hazardous weather outlook, Apr 21, 3:47 AM MST, 14 hours 28 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
447 AM MDT THU APR 21 2011

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-221300-
BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK-
NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS-
SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-
WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH-
447 AM MDT (547 AM CDT) THU APR 21 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

STRONG SOUTHERLY WINDS ARE EXPECTED TODAY ACROSS CENTRAL SOUTH
DAKOTA AND PORTIONS OF THE SOUTH DAKOTA PLAINS. WINDS OF 25 TO 35
MPG WITH GUSTS TO 45 MPH WILL DEVELOP THIS MORNING AND CONTINUE
UNTIL THE EARLY EVENING.

ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHEAST WYOMING AND
FAR WESTERN SOUTH DAKOTA THIS AFTERNOON AND EVENING. WIDESPREAD
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A STORM SYSTEM WILL BRING MORE PRECIPITATION TO THE AREA FRIDAY.
THE STORM WILL ALSO BRING STRONG NORTHWEST WINDS TO THE AREA. WINDS
OF 30 TO 40 MPH WILL BE POSSIBLE ACROSS WESTERN SOUTH DAKOTA AND
NORTHEAST WYOMING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

The radar

The Rapid City radar (KUDX), 30 km away, was scanning. The volume nearest the first event began at 01:16 UTC.

Open the radar archive at this moment

Event by event

3 hail. Local standard time, as filed.

Hail, Pennington

When
April 21, 6:15 PM MST to 6:30 PM MST
Where
Pennington County, 1 mi ESE of Rapid City
Measured
0.75 in hail
Reported by
Official NWS Observations
Coordinates
44.075, -103.201

Penny sized hail covered the ground.

Hail, Pennington

When
April 21, 6:40 PM MST
Where
Pennington County, 6 mi ESE of Rapid City
Measured
0.75 in hail
Reported by
Public
Coordinates
44.047, -103.108

Hail, Pennington

When
April 21, 6:50 PM MST
Where
Pennington County, (Rap)rapid City Arpt
Measured
0.75 in hail
Reported by
Trained Spotter
Coordinates
44.050, -103.050

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in South Dakota in 2011Every state in 2011This day in weather historyWarnings in South Dakota, April 2011

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: 289081, 289082, 289083.