Overview
A strong, early spring storm moved across the region on the 9th and 10th of April 2011. On Saturday (April 9th), a warm front was the focus for severe thunderstorm development, and resulted in several tornadoes over northwest Iowa along with large hail and damaging winds. On Sunday, April 10th, the warm front pushed north across northern Wisconsin. The severe weather focus shifted to a low pressure area and associated cold front that would eventually push through the region. The atmosphere was unstable ahead of the front with favorable winds for storm organization, which included Supercells capable of tornadoes. Storms started to rapidly develop around 3 p.m. with many producing severe weather within 20 to 30 minutes of initiation. The storm movement was very fast - nearly 70 mph at times. The severe thunderstorms produced very large hail, damaging winds, and a few tornadoes. Storm surveys confirmed two tornadoes in central Wisconsin (Adams / Waushara Counties) and wind damage in parts of Houston County, MN (near Caledonia) and around Osseo, WI. Hail up to 3 inches in diameter pelted the southern sections of La Crosse as well as neighboring areas in Minnesota. Car, roof, and siding damage was common. Golf ball sized hail fell at the NWS La Crosse office for a brief period. There were 15 tornadoes in Wisconsin on Sunday, April 10th, which set a new record for the most ever for an April day in Wisconsin. The previous record was set on April 27, 1984, when 10 tornadoes occurred, with 3 fatalities and 42 injuries. That day in 1984 had two F4 intensity tornadoes which have winds of 207-260 mph. On Sunday, the strongest tornado surveyed was EF3 intensity (which has winds around 150 mph). For more information on the Wisconsin tornadoes, see the NWS Milwaukee summary, or the write up from . |
Tornadoes:
Tornado - Necedah, WI
Track Map |
Tornado - Arkdale / Cottonville, WI
Track Map |
Tornado - 5 miles SW Hancock, WI
Track Map |
The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:
EF0 Weak 65-85 mph |
EF1 Moderate 86-110 mph |
EF2 Significant 111-135 mph |
EF3 Severe 136-165 mph |
EF4 Extreme 166-200 mph |
EF5 Catastrophic 200+ mph |
Photos:
Arkdale - Cottonville Tornado
Damage from Necedah, WI area tornado
La Crosse, WI area large hail
Large hail near La Crosse, WI | Large hail near La Crosse, WI (Photo by John Wetenkamp) |
Siding damage on the south side of La Crosse, WI | Siding damage on the south side of La Crosse, WI |
Hail embedded in the ground, south side of La Crosse |
Radar:
Radar depiction of the rotation near Cottonville, WI | Radar animation from approx. 3:30 p.m. to 8 p.m. (every 10 min) | Radar animation from approx. 3:30 p.m. to 10 p.m. | Reflectivity image as storms approached La Crosse, WI (4:37 p.m.) |
Reflectivity animation of large hail producer that moved across southern La Crosse. | Reflectivity image as storms moved across Juneau and Adams Counties (6:18 p.m.) | Storm relative motion image depicting circulation in storm near Cottonville, WI (7:04 p.m.) |
Storm Reports
PRELIMINARY LOCAL STORM REPORT...SUMMARY NATIONAL WEATHER SERVICE LA CROSSE WI 400 PM CDT MON APR 11 2011 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0423 AM HAIL NEW HAMPTON 43.06N 92.31W 04/10/2011 M0.50 INCH CHICKASAW IA LAW ENFORCEMENT 0340 PM HAIL ELMA 43.25N 92.44W 04/10/2011 M0.75 INCH HOWARD IA EMERGENCY MNGR 40-50 MPH ESTIMATED WIND ALSO 0350 PM HAIL NELSON 44.42N 92.00W 04/10/2011 M1.00 INCH BUFFALO WI TRAINED SPOTTER 0400 PM HAIL 7 W HARMONY 43.56N 92.15W 04/10/2011 M0.75 INCH FILLMORE MN EMERGENCY MNGR ALSO REPORTED 40 MPH WINDS 0403 PM HAIL 4 N HARMONY 43.61N 92.01W 04/10/2011 E0.50 INCH FILLMORE MN LAW ENFORCEMENT 0411 PM TSTM WND DMG 2 N BURR OAK 43.48N 91.88W 04/10/2011 WINNESHIEK IA LAW ENFORCEMENT SOME TREES AND POWER LINES DOWN AND BUILDING DAMAGE 0415 PM TSTM WND DMG 4 E CANTON 43.53N 91.85W 04/10/2011 FILLMORE MN LAW ENFORCEMENT BARN DOWN AND 1 TREE DOWN ON ROAD 0420 PM TSTM WND DMG 2 SW CANTON 43.51N 91.96W 04/10/2011 FILLMORE MN TRAINED SPOTTER 2 FOOT DIAMETER TREE DOWN BLOCKING THE ROAD. 0424 PM HAIL NELSON 44.42N 92.00W 04/10/2011 E0.88 INCH BUFFALO WI FIRE DEPT/RESCUE ALSO SEEING OCCASIONAL WALL CLOUD WITH SOME SLIGHT LOWERING. NO ROTATION AT THIS TIME. 0427 PM HAIL HOUSTON 43.76N 91.57W 04/10/2011 M1.75 INCH HOUSTON MN EMERGENCY MNGR 0430 PM TSTM WND DMG 5 N CALEDONIA 43.71N 91.50W 04/10/2011 HOUSTON MN EMERGENCY MNGR MOBILE HOME KNOCKED OFF FOUNDATION 0432 PM HAIL GOODVIEW 44.07N 91.71W 04/10/2011 E1.00 INCH WINONA MN TRAINED SPOTTER 0432 PM TSTM WND DMG CALEDONIA 43.63N 91.50W 04/10/2011 HOUSTON MN EMERGENCY MNGR BARN DOWN JUST OUTSIDE CALEDONIA 0434 PM HAIL 1 N MONDOVI 44.58N 91.67W 04/10/2011 E1.00 INCH BUFFALO WI PUBLIC MULTIPLE REPORTS OF HAIL AROUND QUARTER SIZE 0434 PM TSTM WND DMG 8 N CALEDONIA 43.75N 91.50W 04/10/2011 HOUSTON MN EMERGENCY MNGR NUMEROUS TREES AND POWER LINES DOWN ALONG HWY 76 0435 PM HAIL 5 E FOUNTAIN CITY 44.12N 91.60W 04/10/2011 E1.25 INCH BUFFALO WI TRAINED SPOTTER 0437 PM HAIL ARCADIA 44.25N 91.49W 04/10/2011 E0.75 INCH TREMPEALEAU WI LAW ENFORCEMENT 0438 PM TSTM WND DMG BLACK HAMMER 43.61N 91.67W 04/10/2011 HOUSTON MN LAW ENFORCEMENT SEVERAL TREES DOWN ALONG COUNTY ROAD 19. POSSIBLE TORNADO TOUCHDOWN. DEPUTY ON THE WAY TO INVESTIGATE. 0442 PM HAIL 2 E HOKAH 43.76N 91.31W 04/10/2011 M2.75 INCH HOUSTON MN EMERGENCY MNGR 0442 PM HAIL HOKAH 43.76N 91.35W 04/10/2011 E3.00 INCH HOUSTON MN TRAINED SPOTTER HAIL COVERING THE GROUND WITH SOME TREES DOWN. 0442 PM HAIL ARCADIA 44.25N 91.49W 04/10/2011 E1.25 INCH TREMPEALEAU WI TRAINED SPOTTER 0444 PM HAIL 1 S HOKAH 43.75N 91.35W 04/10/2011 M1.00 INCH HOUSTON MN CO-OP OBSERVER ALSO 0.50 INCHES OF RAIN IN LESS THAN 5 MINUTES AND VERY STRONG WINDS. POWER WENT OUT. 0445 PM HAIL 3 NW BROWNSVILLE 43.73N 91.32W 04/10/2011 E1.75 INCH HOUSTON MN TRAINED SPOTTER 0445 PM TSTM WND DMG 5 N CALEDONIA 43.71N 91.50W 04/10/2011 HOUSTON MN LAW ENFORCEMENT BARN DOWN AND TRAILER BLOWN OFF ITS FOUNDATION. 0451 PM TSTM WND GST 2 S LA CROSSE 43.80N 91.23W 04/10/2011 E60.00 MPH LA CROSSE WI AMATEUR RADIO 0451 PM HAIL 2 S LA CROSSE 43.80N 91.23W 04/10/2011 E1.50 INCH LA CROSSE WI AMATEUR RADIO HALF DOLLAR SIZE HAIL 0452 PM HAIL 2 S LA CROSSE 43.80N 91.23W 04/10/2011 E1.00 INCH LA CROSSE WI LAW ENFORCEMENT ON WARD AVENUE IN SOUTH LA CROSSE 0453 PM HAIL 2 S LA CROSSE 43.80N 91.23W 04/10/2011 E2.00 INCH LA CROSSE WI PUBLIC EXTENSIVE HAIL DAMAGE ON THE SOUTH SIDE OF LA CROSSE NEAR WAL MART. WINDOWS BROKEN AND SIDING DAMAGED TO AN ESTIMATED 10 TO 15 HOMES. SEVERAL VEHICLES ALSO DAMAGED WITH DENTS AND BROKEN WINDOWS AND MIRRORS. 0453 PM HAIL 3 SE LA CROSSE 43.80N 91.19W 04/10/2011 E2.50 INCH LA CROSSE WI AMATEUR RADIO AT SOUTHERN BLUFFS SCHOOL 0454 PM HAIL 2 S LA CROSSE 43.80N 91.23W 04/10/2011 E2.00 INCH LA CROSSE WI AMATEUR RADIO SOUTH SIDE 0454 PM HAIL 3 E LA CROSSE 43.83N 91.17W 04/10/2011 E1.75 INCH LA CROSSE WI NWS EMPLOYEE AT NWS OFFICE 0454 PM HAIL 5 S OSSEO 44.51N 91.22W 04/10/2011 E1.75 INCH TREMPEALEAU WI TRAINED SPOTTER 0455 PM HAIL 3 E LA CROSSE 43.83N 91.17W 04/10/2011 M1.75 INCH LA CROSSE WI LAW ENFORCEMENT AT HWY 14 AND CTH MM 0456 PM TSTM WND GST 1 E LA CROSSE 43.83N 91.21W 04/10/2011 M52.00 MPH LA CROSSE WI NWS EMPLOYEE AT NWS OFFICE 0459 PM HAIL WEST SALEM 43.90N 91.08W 04/10/2011 M1.00 INCH LA CROSSE WI NWS EMPLOYEE ALSO 40 MPH WIND 0500 PM TSTM WND DMG OSSEO 44.58N 91.22W 04/10/2011 TREMPEALEAU WI TRAINED SPOTTER LOTS OF WINDOWS BROKEN AND CARS DENTED FROM WHAT APPEARS TO BE WIND BLOWN DEBRIS. 0510 PM TSTM WND DMG 1 N GENOA 43.59N 91.23W 04/10/2011 VERNON WI LAW ENFORCEMENT POWERLINES DOWN ON MOUND RIDGE RD 0516 PM HAIL 1 S SPARTA 43.93N 90.81W 04/10/2011 M1.00 INCH MONROE WI LAW ENFORCEMENT AT I-90 EXIT 25 0525 PM HAIL 7 E SPARTA 43.94N 90.67W 04/10/2011 M1.75 INCH MONROE WI LAW ENFORCEMENT AT HWY 16 AND CTH A 0530 PM HAIL 1 N TOMAH 44.00N 90.50W 04/10/2011 M1.25 INCH MONROE WI TRAINED SPOTTER 0530 PM HAIL MEDFORD 45.14N 90.35W 04/10/2011 E1.00 INCH TAYLOR WI PUBLIC 0532 PM HAIL TUNNEL CITY 44.00N 90.57W 04/10/2011 M0.50 INCH MONROE WI TRAINED SPOTTER 0536 PM FUNNEL CLOUD 3 SW OAKDALE 43.93N 90.42W 04/10/2011 MONROE WI LAW ENFORCEMENT POSSIBLE FUNNEL REPORTED BY PUBLIC 0538 PM HAIL 2 W TOMAH 43.99N 90.54W 04/10/2011 M0.75 INCH MONROE WI TRAINED SPOTTER 0538 PM HAIL WARRENS 44.13N 90.50W 04/10/2011 E1.00 INCH MONROE WI AMATEUR RADIO 0539 PM HAIL 3 W WITHEE 44.95N 90.66W 04/10/2011 M0.25 INCH CLARK WI LAW ENFORCEMENT 0540 PM HAIL TOMAH 43.99N 90.50W 04/10/2011 E2.50 INCH MONROE WI STORM CHASER HAIL MEASUREMENTS BETWEEN GOLF BALL AND TENNIS BALL SIZE. WIND GUSTS ALSO ESTIMATED AROUND 70 MPH. 0542 PM HAIL 4 SW STETSONVILLE 45.04N 90.37W 04/10/2011 E1.00 INCH TAYLOR WI LAW ENFORCEMENT 0608 PM TSTM WND DMG 3 SE NECEDAH 43.99N 90.03W 04/10/2011 JUNEAU WI LAW ENFORCEMENT 8 TO 10 INCH PINE TREES UPROOTED AND A GARAGE DOWN. WINDS ESTIMATED 60 MPH. 0610 PM TSTM WND GST VOLK FIELD 43.93N 90.27W 04/10/2011 M56.00 MPH JUNEAU WI ASOS 0610 PM TSTM WND DMG NECEDAH 44.02N 90.07W 04/10/2011 JUNEAU WI LAW ENFORCEMENT FUNNEL CLOUD WITH TREES DOWN. 0610 PM TORNADO 1 NW ARKDALE 44.04N 89.90W 04/10/2011 ADAMS WI PUBLIC POSSIBLE TORNADO REPORTED BY PUBLIC. CONSIDERABLE TREE DAMAGE. 0612 PM TORNADO 1 W ARKDALE 44.03N 89.90W 04/10/2011 F2 ADAMS WI LAW ENFORCEMENT EF2. 17 MILE LENGTH. 1/2 MILE MAX WIDTH. FROM JUST WEST OF ARKDALE TO COTTONWOOD TO COUNTY RD G. 0618 PM HAIL 1 E NECEDAH 44.02N 90.05W 04/10/2011 M1.25 INCH JUNEAU WI AMATEUR RADIO 0618 PM HAIL 5 ENE MEDFORD 45.17N 90.25W 04/10/2011 E1.75 INCH TAYLOR WI LAW ENFORCEMENT 0618 PM HAIL 3 SE NECEDAH 43.99N 90.03W 04/10/2011 M1.25 INCH JUNEAU WI AMATEUR RADIO 0623 PM HAIL BIG FLATS 44.12N 89.80W 04/10/2011 E1.00 INCH ADAMS WI TRAINED SPOTTER 0625 PM TSTM WND DMG COTTONVILLE 44.06N 89.81W 04/10/2011 ADAMS WI TRAINED SPOTTER TREES DOWN. 0630 PM HAIL NEW ROME 44.24N 89.88W 04/10/2011 E0.75 INCH ADAMS WI TRAINED SPOTTER 0630 PM TORNADO COTTONVILLE 44.06N 89.81W 04/10/2011 ADAMS WI AMATEUR RADIO REPORTED BY SPOTTER 0630 PM TORNADO 7 E COTTONVILLE 44.06N 89.67W 04/10/2011 F1 ADAMS WI LAW ENFORCEMENT EF1 0725 PM HAIL 2 S FRIENDSHIP 43.95N 89.82W 04/10/2011 M0.88 INCH ADAMS WI TRAINED SPOTTER DIME HAIL IN ADAMS 0727 PM HAIL ADAMS 43.96N 89.82W 04/10/2011 E0.75 INCH ADAMS WI TRAINED SPOTTER
2-Day Rain Reports (April 9-10)
PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1122 AM CDT MON APR 11 2011 ...RAINFALL TOTALS FOR APRIL 9TH-10TH... LOCATION COUNTY RAINFALL NORTHEAST IOWA ST. ANSGAR MITCHELL 0.97 OSAGE MITCHELL 0.81 CRESCO 1NE HOWARD 0.69 DECORAH AWOS WINNESHIEK 0.26 NEW HAMPTON CHICKASAW 0.21 CHARLES CITY FLOYD 0.20 WAUKON ALLAMAKEE 0.20 LANSING 4SE ALLAMAKEE 0.11 IONIA CHICKASAW 0.10 VOLGA FAYETTE 0.03 ELKADER 6SSW FAYETTE 0.01 SOUTHEAST MINNESOTA GRAND MEADOW MOWER 2.44 LA CRESCENT 1N HOUSTON 1.73 SPRING VALLEY FILLMORE 1.72 LA CRESCENT HOUSTON 1.71 AUSTIN AWOS MOWER 1.66 SPRING VALLEY 3E FILLMORE 1.62 WINONA AWOS WINONA 1.61 WINONA LOCK AND DAM 5A WINONA 1.61 LANESBORO FILLMORE 1.33 ROCHESTER 2NE OLMSTED 1.32 ROCHESTER ASOS OLMSTED 1.22 PRESTON FILLMORE 1.20 PRESTON AWOS FILLMORE 1.14 MINNESOTA CITY WINONA 1.13 SPRING GROVE HOUSTON 1.09 WABASHA WABASHA 1.08 THEILMAN WABASHA 1.04 HIGHLAND FILLMORE 0.95 ELGIN 2SSW WABASHA 0.77 BYRON OLMSTED 0.75 DODGE CENTER AWOS DODGE 0.63 LAKE CITY WABASHA 0.51 CALEDONIA HOUSTON 0.31 SOUTHWEST WISCONSIN FRENCH ISLAND LA CROSSE 2.10 LA CROSSE ASOS LA CROSSE 1.92 WARRENS 5WSW MONROE 1.89 GALESVILLE 2ESE TREMPEALEAU 1.76 SPARTA MONROE 1.73 TUNNEL CITY 1S MONROE 1.65 FOUR CORNERS MONROE 1.62 BLAIR 2NW TREMPEALEAU 1.58 NEILLSVILLE 3SW CLARK 1.55 TREMPEALEAU TREMPEALEAU 1.49 WEST SALEM LA CROSSE 1.43 BLACK RIVER FALLS JACKSON 1.38 ALMA BUFFALO 1.23 SPARTA - FT MCCOY AWOS MONROE 1.22 MEDFORD TAYLOR 1.07 LA CROSSE WFO LA CROSSE 0.98 GAD TAYLOR 0.83 ROCK DAM CLARK 0.70 OWEN 2N CLARK 0.60 OSSEO TREMPEALEAU 0.60 NEW LISBON 4ENE JUNEAU 0.36 FRIENDSHIP ADAMS 0.35 WESTBY 3ENE VERNON 0.28 RICHLAND CENTER RICHLAND 0.26 GENOA VERNON 0.17 RICHLAND CENTER 4N RICHLAND 0.17 GAYS MILLS CRAWFORD 0.13 VIROQUA VERNON 0.12 ONTARIO VERNON 0.12 STEUBEN 4SE CRAWFORD 0.10 SOLDIERS GROVE CRAWFORD 0.09 LA FARGE VERNON 0.09 HILLSBORO VERNON 0.06 LYNXVILLE CRAWFORD 0.06 PRAIRIE DU CHIEN AWOS CRAWFORD 0.05 BOSCOBEL AWOS GRANT 0.05 PRAIRIE DU CHIEN CRAWFORD 0.04 PLATTEVILLE GRANT 0.02 OBSERVATIONS ARE COLLECTED FROM A VARIETY OF SOURCES WITH VARYING EQUIPMENT AND EXPOSURE. NOT ALL DATA LISTED IS CONSIDERED OFFICIAL. FOR THIS...AND A WEALTH OF OTHER RIVER AND WEATHER INFORMATION... VISIT OUR WEBSITE AT WEATHER.GOV/LACROSSE
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