South Dakota, 2002

Damaging Winds in South Dakota, July 20, 2002

July 20, 2002 · NWS UNR · 2 events in 2 counties and zones

An extremely strong severe thunderstorm moved over Rapid City and across the adjacent plains east of town. Downburst winds and the associated gust front caused damage along a nearly 30 mile long path.

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

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The toll

Deaths
0
Injuries
0
Property damage
$1.0 million
Crop damage
None recorded
Events
2

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.

An extremely strong severe thunderstorm moved over Rapid City and across the adjacent plains east of town. Downburst winds and the associated gust front caused damage along a nearly 30 mile long path. Extensive tree damage occurred throughout the eastern half of the city with countless trees and branches in excess of 24 inch diameter felled. Two roofs were torn off by the winds. Flying debris damaged numerous cars and buildings. The NWS office in downtown Rapid City measured an 80 mph wind gust, with meteorologists noting winds were sustained at 60 to 70 mph for 5 minutes. Ellsworth AFB wind equipment measured a 106 mph wind gust from the thunderstorm as it passed. Costs associated only with tree damage and cleaning up debris were conservatively estimated at $500,000.

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 Jul 20, 6:22 PM MST, 1 hour 36 minutes earlier.

Area forecast discussion, Jul 20, 6:22 PM MST, 1 hour 36 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
722 PM MDT SAT JUL 20 2002

THE FORECAST WAS UPDATED TO MENTION LOCALLY HEAVY RAINFALL ACROSS
SOUTHWESTERN AND SOUTH-CENTRAL SD...OTHERWISE NO MAJOR CHANGES WERE
MADE. TONIGHT IS AGAIN QUITE SIMILAR TO LAST NIGHT...EXCEPT THAT THE
MOISTURE AND INSTABILITY AXES ARE SHIFTED SLIGHTLY EASTWARD. THE
MAIN THUNDERSTORM CLUSTER WAS TAKING SHAPE OVER OUR SOUTHWESTERN
CWFA...AND THIS IS EXPECTED TO MOVE/DEVELOP EAST-NORTHEASTWARD
ACROSS SOUTHERN SD. THE SURFACE BOUNDARY THAT HAS BEEN AROUND FOR
THE LAST SEVERAL DAYS HAS NOW PUSHED INTO SOUTH-CENTRAL SD...AND IT
WILL NOT MOVE MUCH FOR THE REST OF THE EVENING. THE MAIN DIFFERENCE
BETWEEN TONIGHT AND OTHER NIGHTS IS THE RATHER STRONG FRONTOGENESIS
ZONE IN THE LOWER ATMOSPHERE...WHICH STRETCHES ACROSS THE SOUTHERN
CWFA. AS THE LOW-LEVEL JET STRENGTHENS AND IMPINGES ON THIS FRONTAL
ZONE LATER TONIGHT...EXPECT MOISTURE CONVERGENCE TO LEAD TO SOME
LOCALLY HEAVY RAINFALL...WITH TRAINING AND SLOW-MOVING CELLS BASED
ON THE THICKNESS PATTERN AND CORFIDI VECTORS. NOT ENOUGH CONFIDENCE
FOR A FLOOD WATCH AT THIS TIME...BUT ONE MAY BE NEEDED AS THE EVENT
UNFOLDS.

.UNR...NONE.

MJB

In the hours before

Local storm report, Jul 20, 4:02 PM MST, 3 hours 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
502 PM MDT SAT JUL 20 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1250 AM    8 NW USTA                 SD   1 INCH HAIL
07/20/02   PERKINS                        REPORTED BY STORM
                                          SPOTTER.

1250 AM    8 NW USTA                 SD   WIND DAMAGE
07/20/02   PERKINS                        REPORTED BY STORM
                                          SPOTTER.

0130 AM    2 W GLAD VLY              SD   60 MPH TSTM GUST
07/20/02   ZIEBACH                        REPORTED BY STORM
                                          SPOTTER. TREE BRANCHES
                                          BROKEN.
Local storm report, Jul 20, 4:41 PM MST, 3 hours 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
541 PM MDT SAT JUL 20 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0307 PM    2 NE SILVER CITY          SD   1.5 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER. LOTS OF 1.0 TO
                                          1.5 INCH HAIL.

0426 PM    4 N DEERFIELD             SD   .75 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER.

0435 PM    8 SE NEWELL               SD   1 INCH HAIL
07/20/02   BUTTE                          REPORTED BY STORM
                                          SPOTTER. NICKEL TO
                                          QUARTER SIZE HAIL.
                                          LEFT-MOVING SUPERCELL
                                          WITH PERSISTENT HAIL
                                          SPIKE.

0507 PM    2 N BLACK HAWK            SD   .88 INCH HAIL
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

0507 PM    2 N BLACK HAWK            SD   60 MPH TSTM GUST
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

ZCZC FSDLSRRAP ALL
TTAA00 KRAP DDHHMM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
541 PM MDT SAT JUL 20 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0307 PM    2 NE SILVER CITY          SD   1.5 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER. LOTS OF 1.0 TO
                                          1.5 INCH HAIL.

0426 PM    4 N DEERFIELD             SD   .75 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER.

0435 PM    8 SE NEWELL               SD   1 INCH HAIL
07/20/02   BUTTE                          REPORTED BY STORM
                                          SPOTTER. NICKEL TO
                                          QUARTER SIZE HAIL.
                                          LEFT-MOVING SUPERCELL
                                          WITH PERSISTENT HAIL
                                          SPIKE.

0507 PM    2 N BLACK HAWK            SD   .88 INCH HAIL
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

0507 PM    2 N BLACK HAWK            SD   60 MPH TSTM GUST
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

ZCZC FSDLSRRAP ALL
TTAA00 KRAP DDHHMM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
541 PM MDT SAT JUL 20 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0307 PM    2 NE SILVER CITY          SD   1.5 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER. LOTS OF 1.0 TO
                                          1.5 INCH HAIL.

0426 PM    4 N DEERFIELD             SD   .75 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER.

0435 PM    8 SE NEWELL               SD   1 INCH HAIL
07/20/02   BUTTE                          REPORTED BY STORM
                                          SPOTTER. NICKEL TO
                                          QUARTER SIZE HAIL.
                                          LEFT-MOVING SUPERCELL
                                          WITH PERSISTENT HAIL
                                          SPIKE.

0507 PM    2 N BLACK HAWK            SD   .88 INCH HAIL
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

0507 PM    2 N BLACK HAWK            SD   60 MPH TSTM GUST
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

ZCZC FSDLSRRAP ALL
TTAA00 KRAP DDHHMM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
624 PM MDT SUN JUL 21 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0858 PM    3 S RAPID CITY            SD   65 MPH TSTM GUST
07/20/02   PENNINGTON                     REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE. EXTENSIVE
                                          TREE DAMAGE. SHINGLES
                                          OFF A FEW HOUSES.

0900 PM    CAPUTA                    SD   WIND DAMAGE
07/20/02   PENNINGTON                     REPORTED BY RETIRED NWS
                                          EMPLOYEE. EXTENSIVE
                                          TREE DAMAGE WITH A FEW
                                          BIG TREES DOWN.

0925 PM    3 E NEW UNDERWOOD         SD   60 MPH TSTM GUST
07/20/02   PENNINGTON                     REPORTED BY PUBLIC.
                                          THREE-INCH TREE LIMBS
                                          DOWN.

1130 PM    KADOKA                    SD   60-65 MPH TSTM GUST
07/20/02   JACKSON                        REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

Bunkers
Local storm report, Jul 20, 5:00 PM MST, 2 hours 58 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
600 PM MDT SAT JUL 20 2002

TIME(MDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0307 PM    2 NE SILVER CITY          SD   1.5 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER. LOWS OF 1.0 TO
                                          1.5 INCH HAIL.

0426 PM    4 N DEERFIELD             SD   .75 INCH HAIL
07/20/02   PENNINGTON                     REPORTED BY STORM
                                          SPOTTER.

0435 PM    8 SE NEWELL               SD   1 INCH HAIL
07/20/02   BUTTE                          REPORTED BY STORM
                                          SPOTTER. NICKEL TO
                                          QUARTER SIZE HAIL.
                                          LEFT-MOVING SUPERCELL
                                          WITH PERSISTENT HAIL
                                          SPIKE.

0507 PM    2 N BLACK HAWK            SD   .88 INCH HAIL
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

0507 PM    2 N BLACK HAWK            SD   60 MPH TSTM GUST
07/20/02   MEADE                          REPORTED BY OFF-DUTY
                                          NWS EMPLOYEE.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 thunderstorm wind. Local standard time, as filed.

Thunderstorm Wind, Pennington

When
July 20, 7:58 PM MST to 8:25 PM MST
Where
Pennington County, 3 mi S of Rapid City
Measured
77 kt (89 mph)
Property damage
$1.0 million
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
44.033, -103.217

Thunderstorm Wind, Meade

When
July 20, 8:13 PM MST
Where
Meade County, (Rca)ellsworth Afb R
Measured
92 kt (106 mph)
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
44.150, -103.117

What these are

Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

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

The same day elsewhere

More

Every storm in South Dakota in 2002Every state in 2002This day in weather historyWarnings in South Dakota, July 2002

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: 5304761, 5304762.