A cold front triggered a line of severe thunderstorms across parts of northeast Iowa during the early morning hours of June 11th. The severe thunderstorms knocked down trees and power lines in Frankville (Winneshiek County), Elgin (Fayette County) and near Waukon (Allamakee County).
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 ARX wrote it up.
A cold front triggered a line of severe thunderstorms across parts of northeast Iowa during the early morning hours of June 11th. The severe thunderstorms knocked down trees and power lines in Frankville (Winneshiek County), Elgin (Fayette County) and near Waukon (Allamakee County).
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 Jun 10, 10:10 PM CST, 2 hours 27 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 1110 PM CDT SUN JUN 10 2012 .SHORT TERM...OVERNIGHT 1024 PM CDT SUN JUN 10 2012 CONVECTION HAS BEGUN A DOWNWARD TREND ACROSS EASTERN MINNESOTA AND CENTRAL IOWA WITH INSTABILITY RAPIDLY FALLING OFF. 11.02Z RAP ANALYSIS SHOWS SBCAPE/MLCAPE HAVING DROPPED DOWN TO AROUND 500-1000 J/KG AND IS MUCH LOWER THAN WHAT PREVIOUS RUNS OF THE RAP/NAM HAD BEEN SHOWING...LIKELY DUE TO SOME HIGHER DEW POINTS THAT THESE MODELS WERE FORECASTING. THIS INSTABILITY AXIS WILL SHIFT EAST AHEAD OF THE COLD FRONT OVERNIGHT...BUT WITH SURFACE TEMPERATURES ON THE DOWNWARD TREND...AM NOT EXPECTED FOR A RESURGENCE OF STRONG CONVECTIVE DEVELOPMENT. THEREFORE...AM NOT EXPECTING MUCH OF A SEVERE THREAT OVERNIGHT WITH PERHAPS A FEW GUSTS IN THE 25 TO 35 KT RANGE OUT OF SOME OF THE LEFTOVER CONVECTION THAT FORMS. ALSO...THE CIRRUS SHIELD FROM THE ANVIL WILL LIKELY REMAIN OVERHEAD THROUGH THE NIGHT AND LIKELY WILL NOT ALLOW FOR ANY CLEARING OR FOG BEFORE DAYBREAK. .LONG TERM...WEDNESDAY THROUGH SUNDAY 315 PM CDT SUN JUN 10 2012 NEARLY ZONAL FLOW WILL INITIALLY DEVELOP BEHIND THE SYSTEM FOR TUESDAY. THE 10.12Z ECMWF...GFS AND GEM ALL SHOW A SHORT WAVE TROUGH COMING ACROSS THE NORTHERN PLAINS WEDNESDAY. THE FORCING WITH THIS WAVE IS EXPECTED TO STAY TO THE NORTHWEST OF THE FORECAST AREA FOR NOW...SO HAVE MAINTAINED THE DRY FORECAST. AFTER THAT...RIDGING BUILDS OVER THE UPPER MIDWEST AND GREAT LAKES UNTIL NEXT WEEKEND. IT THEN LOOKS LIKE A SOUTHWEST FLOW WILL START TO DEVELOP AS THE RIDGE BEGINS TO MOVE OFF. SHORT WAVE TROUGHS IN THIS SOUTHWEST FLOW ARE EXPECTED TO BEGIN MOVING ACROSS THE REGION BRINGING SOME RAIN CHANCES STARTING SATURDAY AND CONTINUING THROUGH SUNDAY. HAVE STAYED WITH THE MODEL CONSENSUS GRIDS FOR NEXT WEEKEND BUT COULD EASILY SEE THESE BEING DELAYED WITH NOTED MODEL BIAS OF BEING TOO FAST WITH SOUTHWEST FLOW SYSTEMS. && .AVIATION...THROUGH 06Z TUESDAY 1110 PM CDT SUN JUN 10 2012 SHOWERS AND THUNDERSTORMS WILL MOVE EAST ALONG AND JUST BEHIND A COLD FRONT THAT CURRENTLY EXTENDS FROM THE TWIN CITIES DOWN TO MASON CITY. IT LOOKS LIKE IT WILL BE ABOUT A 3-4 HOUR PERIOD OF CONVECTION WITH SOME INTERMITTENT THUNDERSTORMS POSSIBLE. CONDITIONS WILL MAINLY BE VFR THOUGH CEILINGS MAY DROP DOWN TO BETWEEN 2-3KFT FOR A PERIOD AS THE SHOWERS AND STORMS MOVE THROUGH OVERNIGHT. WINDS WILL GO LIGHT AFTER THE FRONT AND CONVECTION PASSES THROUGH...BUT CLOUD COVER WILL LIKELY PERSIST THROUGH DAYBREAK. THUS...AM NOT EXPECTING ANY FOG TO FORM AT RST OR LSE THIS MORNING. WINDS WILL INCREASE INTO THE 20-25KT RANGE THIS AFTERNOON AS A SECONDARY COLD FRONT MOVES THROUGH THE REGION. && .ARX WATCHES/WARNINGS/ADVISORIES... 315 PM CDT SUN JUN 10 2012 WI...NONE. MN...NONE. IA...NONE. && SHORT TERM...HALBACH LONG TERM...04 AVIATION...HALBACH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 1007 PM CDT SUN JUN 10 2012 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-111200- 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- 1007 PM CDT SUN JUN 10 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST TO NORTH CENTRAL WISCONSIN. .DAY ONE...OVERNIGHT SOME THUNDERSTORMS ARE EXPECTED OVERNIGHT BUT SEVERE WEATHER IS NOT ANTICIPATED. HOWEVER...SOME LOCALLY GUSTY WINDS TO 40 MPH WILL BE POSSIBLE WITH SOME OF THE SHOWERS AND THUNDERSTORMS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THUNDERSTORMS ARE POSSIBLE NORTH OF INTERSTATE 90 WEDNESDAY NIGHT AND ACROSS THE ENTIRE AREA FRIDAY NIGHT INTO SATURDAY. IT IS TOO EARLY TO DISCERN WHETHER ANY OF THESE THUNDERSTORMS WILL BECOME SEVERE WEDNESDAY INTO WEDNESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED OVERNIGHT. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. AJ/HALBACH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 908 PM CDT SUN JUN 10 2012 MNZ079-086-087-094-110230- DODGE-MOWER-OLMSTED-WABASHA- 908 PM CDT SUN JUN 10 2012 AT 904 PM...DOPPLER RADAR INDICATED A CLUSTER OF THUNDERSTORMS WEST OF AUSTIN AND BLOOMING PRAIRIE...MOVING NORTHEAST AT 60 MPH. WIND GUSTS OF 35 TO 50 MPH MAY ACCOMPANY THESE SHOWERS AND THUNDERSTORMS. THE STRONG THUNDERSTORM WILL BE NEAR... EDEN...WASIOJA...CLAREMONT AROUND 920 PM... BERNE AND CONCORD AROUND 930 PM... THESE WIND GUSTS COULD BLOW AROUND OUTDOOR FURNITURE AND OTHER LIGHT OBJECTS. SMALL BRANCHES MAY ALSO FALL. HALBACH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 105 AM CDT MON JUN 11 2012 IAZ010-011-019-029-030-MNZ088-WIZ053-054-110700- ALLAMAKEE-CHICKASAW-CLAYTON-CRAWFORD-FAYETTE-VERNON-WINNESHIEK- WINONA- 105 AM CDT MON JUN 11 2012 AT 1258 AM...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS FROM NEAR NEW HAMPTON IOWA TO JUST WEST OF OELWEIN IOWA...MOVING NORTHEAST AT 45 MPH. WIND GUSTS OF 40 TO 50 MPH MAY ACCOMPANY THESE STRONG THUNDERSTORMS. LOCATIONS THAT MAY BE AFFECTED INCLUDE... HAWKEYE...SPILLVILLE...FORT ATKINSON...WEST UNION...RIDGEWAY... DECORAH AND OSSIAN. DAS
The La Crosse radar (KARX), 78 km away, was scanning. The volume nearest the first event began at 06:36 UTC.
4 thunderstorm wind. Local standard time, as filed.
A two foot diameter tree and power lines were blown down in Frankville.
Trees were blown down on Old Stage Road three miles west-northwest of Waukon.
Trees were blown down on Dug Road three miles northeast of Waukon.
Numerous trees were blown down in Elgin.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2012Every state in 2012This day in weather historyWarnings in Iowa, June 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: 383066, 383069, 383071, 383073.