Hail, Campbell
- When
- July 21, 3:47 PM MST
- Where
- Campbell County, 9.32 mi SSE of Gillette
- Measured
- 0.88 in hail
- Reported by
- Trained Spotter
- Coordinates
- 44.160, -105.450
Hail and Damaging Winds in Wyoming, July 21, 2010
Large hail and strong wind gusts accompanied a severe thunderstorm from south of Gillette to west of Upton.
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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $10,000
- Crop damage
- None recorded
- Events
- 4
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.
Large hail and strong wind gusts accompanied a severe thunderstorm from south of Gillette to west of Upton.
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 21, 12:45 PM MST, 3 hours 2 minutes earlier.
Area forecast discussion, Jul 21, 12:45 PM MST, 3 hours 2 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 145 PM MDT WED JUL 21 2010 .DISCUSSION...20Z ANALYSIS SHOWS A SURFACE HIGH SHIFTING TO THE NORTHEAST WITH SOUTHEASTERLY TO NORTHEASTERLY FLOW OVER MUCH OF THE AREA. AT THE UPPER LEVELS...THE WATER VAPOR IMAGERY SHOWS A TROUGH DIGGING OVER THE PACIFIC NW AND SOUTHWESTERLY FLOW OVER THE FORECAST AREA. TONIGHT AND THURSDAY...THUNDERSTORMS WILL LIKELY PERSIST INTO THE OVERNIGHT HOURS GIVEN THE CONSIDERABLE INSTABILITY PRESENT IN MODEL SOUNDINGS AND NOCTURNAL JET DEVELOPING OVER SOUTH CENTRAL SD. A COLD FRONT WILL MOVE IN FROM THE NORTH LATE OVERNIGHT...REACHING RAPID CITY BY EARLY THURSDAY MORNING. CAPPING CIN AND REDUCED SURFACE WIND SHEAR WILL REDUCE THUNDERSTORM COVERAGE THURSDAY...ALTHOUGH A CHANCE OF SEVERE WEATHER WILL REMAIN THURSDAY INTO THURSDAY NIGHT. FOR FRIDAY AND FRIDAY NIGHT...CHANCE OF THUNDERSTORMS CONTINUES AS SURFACE LOW SLIDES EASTWARD AND ASSOCIATED COLD FRONT PUSHES THROUGH THE CWA. AMPLE MOISTURE IN PLACE AS MODELS INDICATE PCP WATER VALUES OF 1.5 INCHES OR 160 PERCENT OF AVERAGE. WINDS AND TEMPERATURES WILL BE TRICKY DUE TO THE FRONTAL POSITION AND TIMING. AT THIS TIME WILL STAY CLOSE TO THE CURRENT FORECAST AND ECMWF SINCE IT SEEMS TO BE TRENDING CLOSER ON THE MODEL TO MODEL RUNS COMPARED TO THE GFS. EXTENDED...A BRIEF DRY PERIOD IS EXPECTED SATURDAY INTO AT LEAST EARLY SUNDAY AS A WEAK RIDGE PASSES OVERHEAD. CHANCES FOR STORMS WILL RETURN BY EARLY NEXT WEEK AS WEST-SOUTHWEST FLOW ALOFT REDEVELOPS. LATEST GFS GUIDANCE IS TRENDING DRIER TOWARD SUNDAY AND MONDAY WITH WEAK RIDGING HOLDING IN PLACE A LITTLE LONGER. WILL KEEP POPS IN UNTIL MORE CONSISTENCY IS SEEN. TEMPERATURES WILL LIKELY REMAIN NEAR OR SLIGHTLY ABOVE AVERAGE. && .AVIATION...THUNDERSTORMS DEVELOPMENT WILL CONTINUE INTO THIS EVENING AND AFFECT MUCH OF THE AREA OVERNIGHT. LOCAL AND BRIEF MVFR/IFR CONDS AS WELL AS GUSTY WINDS CAN BE EXPECTED IN AND NEAR ANY TSTMS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && VAN CLEAVE/SMITH/CALDERON
Hazardous weather outlook, Jul 21, 9:50 AM MST, 5 hours 57 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RAPID CITY SD 1050 AM MDT WED JUL 21 2010 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- 1050 AM MDT (1150 AM CDT) WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS WILL BE PRESENT OVER THE AREA THIS MORNING. WITH DAYTIME HEATING...THUNDERSTORMS WILL INCREASE IN COVERAGE THIS AFTERNOON. SOME STORMS MAY BE SEVERE WITH STRONG WINDS...LARGE HAIL...AND PERHAPS AN ISOLATED TORNADO OVER SOUTH-CENTRAL SOUTH DAKOTA. LOCALLY HEAVY RAIN IS ALSO POSSIBLE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THERE IS A DAILY CHANCE OF THUNDERSTORMS FROM WEDNESDAY THROUGH FRIDAY. SATURDAY LOOKS LIKE THE LONE DRY DAY...WITH THUNDERSTORM CHANCES RETURNING FOR SUNDAY AFTERNOON THROUGH TUESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY.
In the hours before
Special weather statement, Jul 21, 12:49 PM MST, 2 hours 58 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RAPID CITY SD 149 PM MDT WED JUL 21 2010 SDZ013-014-031-032-073-212030- HAAKON SD-NORTHERN MEADE CO PLAINS SD-PENNINGTON CO PLAINS SD-SOUTHERN MEADE CO PLAINS SD-ZIEBACH SD- 149 PM MDT WED JUL 21 2010 ...SIGNIFICANT WEATHER ADVISORY FOR EXTREME NORTHEASTERN PENNINGTON...EASTERN MEADE...NORTHERN HAAKON AND ZIEBACH COUNTIES UNTIL 230 PM MDT... AT 144 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 9 MILES WEST OF GREEN GRASS TO 10 MILES SOUTHWEST OF BRIDGER...AND MOVING SOUTHEAST AT 40 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN. LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE... SOUTH EAGLE BUTTE... MILESVILLE... BILLSBURG... CHERRY CREEK... KIRLEY... THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. WETENKAMP
Local storm report, Jul 21, 12:59 PM MST, 2 hours 48 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
159 PM MDT WED JUL 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0154 PM HEAVY RAIN 7 SW SHADEHILL 45.69N 102.29W
07/21/2010 E2.97 INCH PERKINS SD CO-OP OBSERVER
2.97 INCHES OF RAIN IN THE LAST 24 HOURS. 2.4 SINCE 700
AM.
&&
WETENKAMPLocal storm report, Jul 21, 1:12 PM MST, 2 hours 35 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
212 PM MDT WED JUL 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0157 PM HEAVY RAIN 8 SSE RALPH 45.67N 103.01W
07/21/2010 M4.20 INCH HARDING SD TRAINED SPOTTER
SMALL CREEKS ARE FLOODING. GRAND RIVER IS RISING...NOT
FLOODING YET. RAINFALL IS SINCE 430 AM MDT.
&&
SMITHLocal storm report, Jul 21, 1:13 PM MST, 2 hours 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
213 PM MDT WED JUL 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1030 PM TSTM WND GST 8 N HULETT 44.80N 104.60W
07/20/2010 E60 MPH CROOK WY PUBLIC
60 MPH WIND GUST. TIME ESTIMATED.
&&
WETENKAMPLocal storm report, Jul 21, 2:03 PM MST, 1 hour 44 minutes before
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</html>Special weather statement, Jul 21, 3:31 PM MST, 16 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RAPID CITY SD 431 PM MDT WED JUL 21 2010 WYZ054-055-057-212315- NORTHERN CAMPBELL WY-SOUTHERN CAMPBELL WY-WYOMING BLACK HILLS WY- 431 PM MDT WED JUL 21 2010 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CROOK AND CENTRAL CAMPBELL COUNTIES UNTIL 515 PM MDT... AT 429 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM WESTON TO 16 MILES SOUTH OF WYODAK...AND MOVING EAST AT 35 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN. LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE... GILLETTE... WESTON... ROZET... THIS INCLUDES INTERSTATE 90 BETWEEN WYOMING MILE MARKERS 115 AND 147... THESE STORMS MAY INTENSIFY...AND A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THIS AREA. BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. WETENKAMP
The radar
The Rapid City radar (KUDX), 209 km away, was scanning. The volume nearest the first event began at 22:46 UTC.
Event by event
2 hail, 2 thunderstorm wind. Local standard time, as filed.
Thunderstorm Wind, Campbell
- When
- July 21, 3:51 PM MST
- Where
- Campbell County, 5 mi S of Rozet
- Measured
- 52 kt (60 mph) estimated gust
- Reported by
- NWS Employee
- Coordinates
- 44.208, -105.200
Wind gusts were estimated at 60 mph.
Hail, Weston
- When
- July 21, 4:14 PM MST to 4:23 PM MST
- Where
- Weston County, 12 mi W of Upton
- Measured
- 2 in hail
- Reported by
- Trained Spotter
- Coordinates
- 44.100, -104.872
Thunderstorm Wind, Weston
- When
- July 21, 4:23 PM MST
- Where
- Weston County, 12 mi W of Upton
- Measured
- 61 kt (70 mph) estimated gust
- Property damage
- $10,000
- Reported by
- Trained Spotter
- Coordinates
- 44.100, -104.872
The combination of large hail and wind broke windows, damaged automobiles, and brought down three to four inch tree branches.
What these are
- Hail
- Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
- 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
- Lightning Strike in Wyoming, July 21, 2010
- Flash Flood in Ohio, July 21, 2010
- Heat in Alabama, July 21 to 26, 2010
- Rip Current in Michigan, July 21, 2010
- Flash Flood and Hail in Vermont, July 21, 2010
- Tornado and Flash Flooding in Iowa, July 21 to 22, 2010
- Damaging Winds and Lightning Strike in North Carolina, July 21, 2010
- Flash Flooding and Hail in Iowa, July 21 to 22, 2010
- Tornado and Flood in Connecticut, July 21, 2010
- Hail and Damaging Winds in New York, July 21, 2010
- Tornadoes and Hail in Maine, July 21, 2010
- Hail and Damaging Winds in New York, July 21, 2010
More
Every storm in Wyoming in 2010Every state in 2010This day in weather historyWarnings in Wyoming, July 2010
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 2026-09-30. Each event’s entry at NCEI: 239690, 239691, 239692, 239694.