Severe thunderstorms that developed in north central South Dakota, and had moved east-southeast across eastern South Dakota, and central Minnesota, eventually moved through the Twin Cities, then in west-central Wisconsin prior, and after midnight, and produced some wind damage.
Every event with a place to put it. Tap one for its entry below.
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 MPX wrote it up.
Severe thunderstorms that developed in north central South Dakota, and had moved east-southeast across eastern South Dakota, and central Minnesota, eventually moved through the Twin Cities, then in west-central Wisconsin prior, and after midnight, and produced some wind damage.
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 Twin Cities, MN wrote its last area forecast discussion before the first event at Aug 3, 4:30 PM CST, 5 hours 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 530 PM CDT FRI AUG 3 2012 .UPDATED FOR 00Z AVIATION DISCUSSION... .DISCUSSION... MAIN FORECAST CONCERN TODAY IS OBVIOUSLY THE POTENTIAL FOR CONVECTION AND SEVERE WEATHER TONIGHT. OTHERWISE THINGS LOOK FAIRLY QUIET THROUGH MOST OF THE FORECAST PERIOD AS THE UPPER RIDGE RETROGRADES TO THE WESTERN PART OF THE CONTINENT AND WE FIND OURSELVES IN PREDOMINANTLY DRY NORTHWEST FLOW. LATEST VISIBLE SATELLITE AND RADAR IMAGERY SHOW CONVECTION OVER THE DAKOTAS NEAR THE SURFACE FRONTAL BOUNDARY. THE SHORTWAVE WHICH WILL DRIVE THINGS EAST TONIGHT IS IMPRESSIVE ON WATER VAPOR IMAGERY.... CURRENTLY MOVING THROUGH MONTANA. THE MODELS ARE IN GENERAL AGREEMENT ON THE TIMING OF THE FRONT TONIGHT... WITH DIFFERENCES IN SOME OF THE CONVECTIVE DETAILS. THERE ARE ALSO A VARIETY OF SOLUTIONS WITH THE CAM RUNS... ALTHOUGH MOST SUGGEST THE DEVELOPMENT OF A SOLID LINE OF CONVECTION NEAR THE MINNESOTA- DAKOTAS BORDER BY 00Z... WHICH WOULD THEN TRACK EAST ACROSS THE REMAINDER OF THE CWFA THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS. BEST GUESS NOW WOULD BE FOR THE MAIN CONVECTIVE LINE TO REACH THE I-35 CORRIDOR AROUND THE 4-5Z TIME FRAME... ALTHOUGH MUCH WILL DEPEND ON HOW THINGS EVOLVE OVER THE NEXT SEVERAL HOURS OVER SOUTH DAKOTA. PLENTY OF INSTABILITY IS PRESENT OVER THE AREA... AND WILL REMAIN IN PLACE THROUGH THE EVENING. DEEP LAYER AND LOW LEVEL SHEAR WILL ALSO INCREASE... AND LOOK TO BE MORE THAN SUFFICIENT FOR GOOD STORM ORGANIZATION AND UPSCALE GROWTH INTO A LINEAR MCS... SO THE SUGGESTIONS FROM THE CAMS AS WELL AS THE SSEO SEEM PRETTY REASONABLE. MAIN THREAT LOOKS TO BE DAMAGING WIND GUSTS... WITH SOME HAIL ALSO POSSIBLE. WOULDN/T RULE OUT THE POSSIBILITY OF A BRIEF TORNADO OVER THE FAR WESTERN PART OF THE AREA IF THERE ARE STILL ANY DISCRETE CELLS OR SUPERCELLS EMBEDDED IN A QLCS STRUCTURE AT THAT POINT. THE COLD FRONT LOOKS TO CLEAR THE AREA SOMETIME SATURDAY MORNING... AND THAT SHOULD TAKE MOST OF THE PCPN WITH IT. SOME ACTIVITY COULD REMAIN OVER THE NORTHERN PART OF THE AREA THROUGH THE DAY AS THE UPPER TROUGH MIGRATES THROUGH... WITH THE HEART OF THE MID-LEVEL COLD POOL STAYING TO OUR NORTH. HIGH PRESSURE BUILDS IN SATURDAY NIGHT AND REMAINS ANCHORED IN PLACE THROUGH SUNDAY NIGHT. ANOTHER FRONT WILL DROP SOUTHEAST THROUGH THE AREA ON MONDAY... BUT WILL BE MOISTURE STARVED AND DOES NOT LOOK TO HAVE VERY STRONG QG FORCING ASSOCIATED WITH ITS UPPER WAVE... SO EXPECT IT TO PUSH THROUGH MOST OF THE AREA DRY. HOWEVER... SOME SHRA/TSRA COULD EVENTUALLY DEVELOP AS IT GETS INTO THE SOUTHERN PART OF THE AREA BY MONDAY NIGHT... SO KEPT SOME LOW POPS TO ACCOUNT FOR THAT POSSIBILITY. AFTER THAT WE LOOK TO REMAIN ON THE NORTHEAST PERIPHERY OF THE EXPANSIVE UPPER RIDGE FOR THE BALANCE OF THE WEEK. SOME INSTABILITY SHOULD RETURN TO THE AREA BY WEDNESDAY... AND FROM THEN THROUGH FRIDAY WE WILL LIKELY SEE A FEW CHANCES FOR PCPN AS SEVERAL WEAK SHORTWAVES MIGRATE AROUND THE UPPER RIDGE AND DROP THROUGH OUR AREA IN THE PREVAILING NORTHWEST MID- UPPER LEVEL FLOW. IT/S POSSIBLE THAT MOST OF THAT ACTIVITY WILL STAY NORTH/EAST OF OUR AREA DEPENDING ON WHERE THE BAROCLINIC ZONE WINDS UP... BUT AT THIS POINT THERE IS SUFFICIENT UNCERTAINTY AND DIVERSITY IN THE NWP SOLUTIONS TO INCLUDE SOME POPS FOR MUCH OF THE PERIOD FROM WEDNESDAY NIGHT THROUGH FRIDAY. && .AVIATION.../00Z TAF ISSUANCE/ HELD ONTO TO THE SPIRIT OF PREVIOUS FORECAST WITH JUST A BIT OF TIMING CHANGES...MAYBE AN HOUR OR SO AT SOME LOCALES. ADDED SOME WIND GUSTS AT KAXN/KRWF/KSTC WITH A 3 HOUR TEMPO ASSOCIATED. SHOULD SEE LINEAR FORM OF CONVECTION IN THE EASTERN DAKOTAS NEXT HOUR OR SO AND THEN MOVE INTO THE AREA AND MOVE EAST INTO WESTERN WI BY 06Z SAT. ACTIVITY EXPECTED TO WEAKEN SOME AS IT CROSSES INTO WISCONSIN. THEN PERIOD OF MVFR CIGS POSSIBLE EARLY IN THE MORNING WITH FROPA...LIFTING AND CLEARING SOME DURING THE LATE MORNING. COULD SEE REDEVELOPMENT INTO KEAU AREA IN THE AFTERNOON AND LEFT VCTS FOR NOW...BUT SHOULD MOVE OUT AFTER 21Z SAT. SOUTHEAST SURFACE WINDS BECOMING WEST TO NORTHWEST WITH FROPA AND PERHAPS A BIT GUSTY INTO THE LATE MORNING/AFTERNOON. KMSP...STILL LOOKS LIKE A 04Z-07Z TIMED EVENT FOR SIG CONVECTION IN THE AREA. SHOULD MOVE OUT THEREAFTER AND HELD ONTO VCSH AND THE MVFR CIGS INTO THE EARLY MORNING. SOUTHEAST WINDS WILL BECOME WEST TO NORTHWEST WITH FROPA INTO SATURDAY MORNING. COULD BE A BIT GUSTY AS SKY CLEARS SOME AND MIXING DEVELOPS. SHOULD CLEAR INTO THE LATE AFTERNOON WITH LIGHTER NORTHWEST WINDS INTO SATURDAY EVENING. /OUTLOOK/ .SUNDAY...VFR WITH POSSIBLE MORNING MVFR CEILINGS. WINDS NW AT 10G15KT. .MONDAY...VFR. WINDS SW AT 10KT. .TUESDAY...VFR/MVFR. WINDS SSW AT 5KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1247 PM CDT FRI AUG 3 2012 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 041800- DOUGLAS-TODD-MORRISON-MILLE LACS-KANABEC-STEVENS-POPE-STEARNS- BENTON-SHERBURNE-ISANTI-CHISAGO-LAC QUI PARLE-SWIFT-CHIPPEWA- KANDIYOHI-MEEKER-WRIGHT-HENNEPIN-ANOKA-RAMSEY-WASHINGTON- YELLOW MEDICINE-RENVILLE-MCLEOD-SIBLEY-CARVER-SCOTT-DAKOTA- REDWOOD-BROWN-NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN-BLUE EARTH- WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN-POLK-BARRON-RUSK- ST. CROIX-PIERCE-DUNN-PEPIN-EAU CLAIRE- 1247 PM CDT FRI AUG 3 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND SOUTHERN MINNESOTA... AND WEST CENTRAL WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO ENTER WEST CENTRAL MINNESOTA FROM THE EASTERN DAKOTAS AFTER 6 PM AND EXPAND EASTWARD ACROSS THE OUTLOOK AREA DURING THE EVENING...REACHING WEST CENTRAL WISCONSIN AROUND MIDNIGHT. DAMAGING WINDS...LARGE HAIL...AND BURSTS OF HEAVY RAINFALL WILL BE POSSIBLE WITH THESE STORMS. THE PRIMARY THREAT FOR SEVERE WEATHER WILL EXIST WEST OF LINE FROM RUSH CITY TO FAIRMONT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THUNDERSTORM CHANCES WILL LINGER INTO SATURDAY FROM SOUTH CENTRAL MINNESOTA INTO WEST CENTRAL WISCONSIN. THOUGH THE THREAT OF SEVERE WEATHER LOOKS TO BE EAST OF THE OUTLOOK AREA SATURDAY...ISOLATED STORMS COULD FLARE UP TO SEVERE LEVELS MID DAY SATURDAY EAST OF THE INTERSTATE 35 CORRIDOR. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL LIKELY BE NEEDED ACROSS WEST CENTRAL MINNESOTA DURING THE LATE AFTERNOON AND EARLY EVENING...AND ACROSS THE REMAINDER OF CENTRAL MINNESOTA TONIGHT.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1029 PM CDT FRI AUG 3 2012
MNZ066>070-074>077-082>085-040430-
BLUE EARTH-BROWN-CARVER-DAKOTA-LE
SUEUR-MCLEOD-NICOLLET-RICE-SCOTT-SIBLEY-STEELE-WASECA-WATONWAN-
1029 PM CDT FRI AUG 3 2012
...THUNDERSTORMS MOVING INTO/DEVELOPING OVER BLUE EARTH...BROWN...
CARVER...DAKOTA...LE SUEUR...MCLEOD...NICOLLET...RICE...SCOTT...
SIBLEY...STEELE...WASECA AND WATONWAN COUNTIES THROUGH 1130 PM CDT...
AT 1026 PM CDT...WEATHER SERVICE RADAR WAS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM PLATO TO 3 MILES NORTHWEST
OF RUSH RIVER TO 8 MILES NORTHEAST OF MADELIA. THESE STORMS WERE
MOVING EAST AT 45 MPH.
WINDS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS.
* LOCATIONS IN OR NEAR THE PATH OF THESE STORMS INCLUDE...
LE SUEUR.
NORTHFIELD.
FARIBAULT.
LAKE CRYSTAL.
MONTGOMERY.
JORDAN.
NEW PRAGUE.
LAKEVILLE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
SEEK SHELTER AND STAY AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.
&&
LAT...LON 4479 9315 4450 9312 4411 9333 4409 9443
4449 9420 4475 9424
TIME...MOT...LOC 0327Z 269DEG 40KT 4479 9405 4449 9407
4413 9429
SPDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1039 PM CDT FRI AUG 03 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1030 PM TSTM WND GST 5 E ST CLOUD 45.55N 94.07W
08/03/2012 M59 MPH SHERBURNE MN ASOS
MEASURED AT ST CLOUD REGIONAL AIRPORT.
&&
TDKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1050 PM CDT FRI AUG 03 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1045 PM TSTM WND GST WACONIA 44.85N 93.79W
08/03/2012 M61 MPH CARVER MN MESONET
&&
RAHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1057 PM CDT FRI AUG 03 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1025 PM TSTM WND DMG 1 W HUTCHINSON 44.89N 94.39W
08/03/2012 MCLEOD MN LAW ENFORCEMENT
LARGE BRANCH DOWN PARTIALLY BLOCKING ROAD NEAR
INTERSECTION OF KAY STREET AND LEA AVENUE.
&&
TDKSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1101 PM CDT FRI AUG 3 2012
MNZ076>078-082>085-091>093-040445-
BLUE EARTH-FARIBAULT-FREEBORN-GOODHUE-LE
SUEUR-MARTIN-RICE-STEELE-WASECA-WATONWAN-
1101 PM CDT FRI AUG 3 2012
...THUNDERSTORMS MOVING INTO/DEVELOPING OVER BLUE EARTH...
FARIBAULT...FREEBORN...GOODHUE...LE SUEUR...MARTIN...RICE...STEELE...
WASECA AND WATONWAN COUNTIES THROUGH 1145 PM CDT...
AT 1058 PM CDT...WEATHER SERVICE RADAR WAS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES SOUTHWEST OF
KILKENNY TO 3 MILES NORTHEAST OF JANESVILLE TO 3 MILES EAST OF
MAPLETON TO 5 MILES SOUTHWEST OF WINNEBAGO. THESE STORMS WERE MOVING
EAST AT 40 MPH.
WINDS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS.
* LOCATIONS IN OR NEAR THE PATH OF THESE STORMS INCLUDE...
JANESVILLE.
ALBERT LEA.
FAIRMONT.
MAPLETON.
WASECA.
WELLS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
&&
LAT...LON 4350 9486 4387 9486 4415 9397 4429 9383
4430 9285 4419 9283 4419 9304 4349 9305
TIME...MOT...LOC 0401Z 262DEG 35KT 4428 9356 4416 9364
4392 9385 4372 9419
SPDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1105 PM CDT FRI AUG 03 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1104 PM TSTM WND GST 2 WSW SHAKOPEE 44.76N 93.51W
08/03/2012 M51 MPH SCOTT MN COUNTY OFFICIAL
&&
JPCThe Minneapolis radar (KMPX), 96 km away, was scanning. The volume nearest the first event began at 04:02 UTC.
10 thunderstorm wind. Local standard time, as filed.
Large tree limbs were blown down near Highway 64, and 190th Street, east of New Richmond.
A large tree was blown down across Highway 35 near Osceola.
A large tree was blown down just north of 160th Street.
Several trees were blown down near Hudson.
A tree was blown down near Somerset.
A large tree was blown down southwest of Little Falls.
A large tree was blown down near Horse Creek.
A few trees were blown down near Roberts.
A large tree was blown down near Range.
A large tree was blown down near Bay City.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2012Every state in 2012This day in weather historyWarnings in Wisconsin, August 2012
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: 390214, 390215, 390216, 390217, 390218, 390221, 390222, 390219, 390223, 390220.