Severe thunderstorms produced damaging winds in the late evening hours of September 2nd across parts of northeast Iowa. Law enforcement reported power outages and several trees down which blocked some streets in Oelwein (Fayette County).
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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 ARX wrote it up.
Severe thunderstorms produced damaging winds in the late evening hours of September 2nd across parts of northeast Iowa. Law enforcement reported power outages and several trees down which blocked some streets in Oelwein (Fayette County). A trained spotter in Strawberry Point (Clayton County) estimated a wind gust of 60 miles per hour.
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 La Crosse, WI wrote its last area forecast discussion before the first event at Sep 2, 7:28 PM CST, 3 hours 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 828 PM CDT FRI SEP 2 2011 .UPDATE... THE NEAR TERM FOCUS CONTINUES TO BE ON THE PRECIPITATION CHANCES OVERNIGHT GOING INTO THE EARLY MORNING HOURS SATURDAY AND WHETHER THERE WILL BE ANY SEVERE WEATHER WITH IT. A MID LEVEL SHORTWAVE TROUGH CURRENTLY RESIDES ACROSS EASTERN NEBRASKA AND FAR NORTHWESTERN IOWA WHICH HAS LED TO A MORE WIDESPREAD AREA OF SHOWERS AND THUNDERSTORMS. THIS SHORTWAVE WILL PROPAGATE EASTWARD OVERNIGHT WITH MOISTURE ADVECTION INCREASING BETWEEN 850-700MB. THE MAIN SURFACE COLD FRONT STILL IS LAGGING BEHIND A BIT WITH IT EXTENDING FROM NORTH OF GREEN BAY AND RUNNING SOUTHWEST TO NORTH OF ROCHESTER. ANY PRECIPITATION THAT FALLS TONIGHT IS EXPECTED TO REMAIN SOUTH OF THIS BOUNDARY...WHICH COULD ACTUALLY PUSH BACK TO THE NORTH A BIT AS THE LOW LEVEL FLOW INCREASES FROM THE SOUTH. WITH THE MEAN LOW TO MID LEVEL FLOW FROM THE SOUTHWEST TO THE NORTHEAST AND THE MAIN INSTABILITY GRADIENT RUNNING FROM OMAHA INTO NORTHEAST IOWA AND FAR SOUTHWESTERN WISCONSIN...WOULD EXPECT THAT PRECIPITATION SHOULD BLOSSOM AND SHIFT NORTHEASTWARD INTO THE REGION FROM IOWA...MAINLY AFTER MIDNIGHT. THUS...HAVE TRENDED A BIT LIGHTER ON THE CHANCES FOR PRECIPITATION THIS EVENING AND BUMPED THEM UP ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN AFTER 6Z. WHILE CHANCES FOR SHOWERS AND STORMS LOOK FAIRLY GOOD...THE SEVERE THREAT APPEARS TO BE DWINDLING AT THIS POINT. THE GREATEST THREAT WOULD BE IF ANY OF THE ONGOING CONVECTION NEAR OMAHA CAN DEVELOP A COLD POOL AND RUN NORTHEASTWARD AND CLIP THE SOUTHERN PORTIONS OF OUR FORECAST AREA. THIS SCENARIO DOES NOT LOOK THAT FAVORABLE THOUGH AS THE PAST FEW RUNS OF THE RUC KEEP THE NOSE OF THE LOW LEVEL JET DOWN ACROSS FAR SOUTHERN IOWA. 0-6KM SHEAR IS BETTER THE FURTHER NORTH YOU GO...BUT MOST OF THAT SHEAR IS CONFINED TO THE LOWEST 3KM. FURTHER SOUTH TOWARD THE WARM SECTOR...THE 00Z DVN SOUNDING SHOWS A FAIRLY DECENT DRY LAYER AROUND 830MB WHICH WOULD BE CONDUCIVE FOR STRONG DOWNBURSTS. THUS...CURRENT THINKING IS THAT THE BEST CHANCES FOR ANY SEVERE WEATHER...IF AT ALL...WILL BE DOWN ACROSS SOUTHERN IOWA WITH STRAIGHT LINE WINDS THE MAIN HAZARD DOWN THERE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && UPDATE...HALBACH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 852 PM CDT FRI SEP 2 2011 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-031200- ADAMS-ALLAMAKEE-BUFFALO-CHICKASAW-CLARK-CLAYTON-CRAWFORD-DODGE- FAYETTE-FILLMORE-FLOYD-GRANT-HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE- MITCHELL-MONROE-MOWER-OLMSTED-RICHLAND-TAYLOR-TREMPEALEAU-VERNON- WABASHA-WINNESHIEK-WINONA- 852 PM CDT FRI SEP 2 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF NORTHEAST IOWA... SOUTHEAST MINNESOTA...AND SOUTHWEST INTO CENTRAL WISCONSIN. .DAY ONE...OVERNIGHT THUNDERSTORMS ARE EXPECTED TO BECOME MORE NUMEROUS TONIGHT...MAINLY AFTER MIDNIGHT...ACROSS MUCH OF THE AREA. THE MAIN FOCUS FOR SEVERE WEATHER IS WITH A CLUSTER OF STORMS THAT HAVE DEVELOPED NEAR OMAHA AND ARE EXPECTED TO TRACK EAST ACROSS SOUTHERN IOWA. AT THIS POINT...IT APPEARS AS THOUGH THEY WILL GO SOUTH OF THE REGION. BUT IF THEY DO END UP CLIPPING PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...DAMAGING WINDS WILL BE THE MAIN SEVERE THREAT FROM THESE STORMS ALONG WITH BRIEF TORRENTIAL DOWNPOURS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY A COLD FRONT WILL PROVIDE THE FOCUS FOR MORE THUNDERSTORMS ON SATURDAY. A FEW OF THESE STORMS COULD BECOME STRONG TO SEVERE...WITH THE HIGHER RISK OVER SOUTHERN WISCONSIN AND NORTHEAST IOWA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED OVERNIGHT...BUT MAY BE NEEDED ON SATURDAY. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. 04/HALBACH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1147 PM CDT FRI SEP 2 2011 IAZ029-030545- FAYETTE- 1147 PM CDT FRI SEP 2 2011 ...SEVERE THUNDERSTORMS APPROACHING FAYETTE COUNTY... AT 1142 PM...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 23 MILES SOUTHWEST OF OELWEIN...MOVING NORTHEAST AT 30 MPH. WIND GUSTS UP TO 60 MPH AND TORRENTIAL DOWNPOURS MAY ACCOMPANY THIS THUNDERSTORM. SEVERE WEATHER HAS BEEN REPORTED WITH THIS STORM. WARNINGS MAY BE NEEDED AS THIS STORM GETS CLOSER THE STORM WILL BE NEAR... OELWEIN...9 MILES SOUTHEAST OF WESTGATE AROUND 1230 AM... 7 MILES SOUTHEAST OF MAYNARD AROUND 1240 AM... COUNTY ROAD W 45 AND 187 AROUND 1250 AM... HEAVY RAIN COULD LEAD TO MINOR FLOODING OR A SHORT PERIOD OF STANDING WATER. STAY CLEAR OF DRAINAGE AREAS AND AVOID AREAS OF HIGH WATER IF THEY DEVELOP. PREPARE NOW FOR POSSIBLE STRONG TO DAMAGING THUNDERSTORM WIND GUSTS. MOVE INDOORS AND AWAY FROM WINDOWS IF A WARNING IS ISSUED. HALBACH
The La Crosse radar (KARX), 140 km away, was scanning. The volume nearest the first event began at 05:14 UTC.
2 thunderstorm wind. Local standard time, as filed.
The roof was blown off of a grain elevator. Numerous trees were also blown down, some of which blocked city streets.
An estimated wind gust of 60 miles per hour occurred in Strawberry Point.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2011Every state in 2011This day in weather historyWarnings in Iowa, September 2011
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: 342020, 342023.