Thunderstorms moving along a cold front produced up to golf ball size hail across southwest and central Wisconsin and lightning struck a communications tower in Juneau County in the morning hours of May 6th.
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.
Thunderstorms moving along a cold front produced up to golf ball size hail across southwest and central Wisconsin and lightning struck a communications tower in Juneau County in the morning hours of May 6th.
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 May 6, 5:56 AM CST, 19 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 656 AM CDT SUN MAY 6 2012 .SHORT TERM...TODAY THROUGH TUESDAY 310 AM CDT SUN MAY 6 2012 FORECAST FOCUS IS ON THE STORM AND SEVERE THREAT TODAY. ONGOING CLUSTER OF THUNDERSTORMS WILL CONTINUE TO PUSH EASTWARD EARLY THIS MORNING. SOME HINTS THAT A WING OF CONVECTION COULD DEVELOP AHEAD OF AND ACROSS THE FORECAST AREA VIA THE HRRR/RAP...AROUND THE 850 MB WARM FRONT AND EDGE OF MOISTURE TRANSPORT. LATEST 88-D IMAGERY INDICATES THAT THIS IS OCCURING. THUNDERSTORMS ARE MOVING INTO 500-1000 J/KG OF MUCAPE...ALTHOUGH MOISTURE TRANSPORT IS EXPECT TO DECREASE AS THE STORMS MOVE IN. EXPECT THE ACTIVITY TO CONTINUE...AND THERE COULD BE A SEVERE THREAT EARLY THIS MORNING...MOSTLY A WIND THREAT. HOWEVER...THIS TOO SHOULD WANE AS THE NEAR SFC LAYER CONTINUES TO STABILIZE. THE MCV SPAWNED FROM THE MORNING CONVECTION WILL TRACK ACROSS NORTHERN WI TODAY...AND SHOULD CONTINUE TO ACT AS THE IMPETUS FOR MORE SHOWERS AND THUNDERSTORMS IN THAT REGION. MEANWHILE AT THE SFC...A COLD FRONT WILL BE WORKING EAST INTO THE AREA THIS AFTERNOON. THE 06.00Z NAM12 SITUATES IT ALONG THE MISSISSIPPI RIVER INTO CENTRAL IA. THE GFS IS A BIT SLOWER...HANGING IT ACROSS EASTERN MN INTO CENTRAL IA. INSTABILITY WILL POOL INTO AND AHEAD OF THE FRONT...WITH CLOSE TO 2000 J/KG OF MUCAPE POSSIBLE ACROSS NORTHEAST IA/SOUTHWEST WI LATER THIS AFTERNOON. THE BULK OF THE INSTABILITY WILL BE FARTHER SOUTH...WITH THE BETTER MOISTURE AND LESS WORKED OVER AIR. EXPECT CONVECTION TO DEVELOP AROUND THE FRONT THIS AFTERNOON AND BECOME THE FOCUS FOR A SEVERE WEATHER THREAT. 0-6 KM SHEAR IS RATHER SMALL...PERHAPS 20 TO 30 KTS...WITH MOST OF THIS IN THE 0-3 KM LAYER. WOULD EXPECT LARGE HAIL AND DAMAGING WINDS TO BE THE MAIN THREATS. HOWEVER...TIMING AND LOCATIONS FOR DEVELOPMENT LATER TODAY IS FAR FROM CLEAR. THE MORNING CONVECTION WILL LEAVE DEBRIS CLOUDS AND NUMEROUS OUTFLOW BOUNDARIES. HOW THESE BOUNDARIES INTERACT WITH THE FRONT...AND IF/WHEN THE ATMOSPHERE RELOADS ARE ALL QUESTIONS THAT HAVE NO DEFINITIVE ANSWER QUITE YET. CONDITIONS WILL HAVE TO BE MONITORED CLOSELY THROUGH THE DAY...AND THE FORECAST ADJUSTED IF NECESSARY. THERE WILL BE A SEVERE RISK LATER TODAY...BUT IT COULD STAY JUST SOUTH OF THE FORECAST AREA...OR BE A SHORT WINDOW OF 2 TO 4 HOURS LATE AFTERNOON/EARLY EVENING FOR NORTHEAST IA/SOUTHWEST WI. HEAVY RAINFALL...AND THE POSSIBILITY OF FLASH FLOODING NEEDS TO BE CONSIDERED TODAY/TONIGHT. 3 HOUR FFG IS EXTREMELY LOW ACROSS PORTIONS OF NORTHEAST IA/SOUTHEAST MN...UNDER 1.25 INCHES IN SOME CASES. PWS REMAIN OVER 200 PERCENT OF NORMAL ALTHOUGH THE WARM CLOUD DEPTH ISN/T OVERLY DEEP AT 3.2 KM. THE SYSTEM IS FAIRLY TRANSITORY...AND A PROLONGED PERIOD OF TRAINING STORMS IS NOT EXPECTED. ANOTHER ELEMENT TO CONSIDER IS WHERE WILL THE FRONT BE LATER THIS AFTERNOON WHEN CONVECTION FIRES AROUND IT. THE SLOWER GFS PAINTS A BLEAKER PICTURE...AND WOULD RESULT IN A GREAT THREAT FOR HIGHER QPF OVER THESE WET COUNTIES. THE NAM...NOT AS MUCH. MESO MODELS HRRR/ARX/RAP ALSO SUGGEST THAT THE SOUTHERN FRINGE OF THE CURRENT PCPN TO THE WEST COULD WEAKEN AS IT APPROACHES SOUTHEAST MN/NORTHEAST IA...LOSING ITS STRONG PUSH OF 850 MB MOISTURE TRANSPORT. WITH ALL THIS IN MIND...WILL OPT TO NOT ISSUE A FLASH FLOOD WATCH. STILL...THIS HAS TO BE MONITORED AS THE DAY UNFOLDS...AND IF ANY HEAVY RAIN BECOMES MORE LIKELY OR IS REALIZED...WARNINGS COULD BE NEEDED. ON TUESDAY...AN UPPER LEVEL TROUGH WILL BE DROPPING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY WITH SOME QG CONVERGENCE IN THE 700-300 MB LAYER. A SFC TROUGH WILL REFLECT THE UPPER LEVEL FORCING...STRETCHING WEST OF A SFC LOW OVER MICH. 1000-850 MB LAYER LAPSE RATES AS HIGH AS 9 C/KM FOR TUE AFTERNOON...WITH A GOOD SLUG OF 850-700 MB COLD AIR ADVECTION. ALL THIS POINTS TO SCATTERED TO WIDESPREAD SHOWERS. THERE WILL LIKELY BE A HEAVY DIURNAL ELEMENT TO THE ACTIVITY...WITH THE AFTERNOON/EVENING BEING THE MOST LIKELY TIME FOR RAINFALL. THE GFS AND NAM EVEN SUGGEST UP TO 500 J/KG OF MUCAPE...SO A FEW THUNDERSTORMS COULD BE POSSIBLE. INVERTED-V LOOK IN THE BUFKIT SOUNDINGS ARE ALSO SUGGESTIVE OF PERHAPS SOME ENHANCED GUSTINESS AROUND THE SHOWERS THAT DEVELOP. WILL ADJUST/INCREASE PCPN CHANCES TO REFLECT THE MOST LIKELY TIME PERIOD/LOCATION FOR THE SHOWERS. .LONG TERM...WEDNESDAY THROUGH SATURDAY 310 AM CDT SUN MAY 6 2012 GFS AND ECMWF CONTINUE TO SHOW GOOD CONSENSUS ON BUILDING IN HIGH PRESSURE WEDNESDAY NIGHT...PERSISTING ACROSS THE REGION INTO FRIDAY MORNING. AN UPPER LEVEL SHORTWAVE TROUGH MOVING EASTWARD ACROSS SOUTHERN CANADA WOULD DRAG A SFC FRONT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FRI/FRI NIGHT...BRINGING ANOTHER THREAT FOR SHOWERS AND THUNDERSTORMS. SOME WIND SHEAR INDICATED VIA THE GFS...BUT LITTLE IF ANY CAPE. SO...SEVERE THREAT LOOKS MINIMAL AT THIS TIME. && .AVIATION...TODAY AND TONIGHT 655 AM CDT SUN MAY 6 2012 THUNDERSTORMS WILL CONTINUE TO FOUND NEAR KLSE THROUGH 06.13Z... AND THEN THERE BE A FEW SHOWERS THROUGH 06.15Z. THINKING THAT THE MVRF CEILINGS WILL RISE TO VFR FOR LATE THIS MORNING AND EARLY AFTERNOON AT BOTH TAF SITES. BEYOND THIS TIME PERIOD...THINKING AT THE MVFR CEILINGS ACROSS SOUTH DAKOTA WILL MOVE EAST INTO THE AREA. THE LARGE SCALE COMPUTER MODELS SUGGEST THAT THERE WILL BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. MEANWHILE THE MESO MODELS SHOW THAT PRECIPITATION WILL BE WELL SOUTH OF THE TAF SITES. DUE TO THIS...THERE IS LITTLE CONFIDENCE FOR LATE THIS AFTERNOON AND TONIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 310 AM CDT SUN MAY 6 2012 WI...NONE. MN...NONE. IA...NONE. && SHORT TERM...RIECK LONG TERM....RIECK AVIATION...BOYNE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LA CROSSE WI 511 AM CDT SUN MAY 6 2012 IAZ008>011-018-019-029-030-MNZ094>096-WIZ053>055-061-071000- ALLAMAKEE-CHICKASAW-CLAYTON-CRAWFORD-FAYETTE-FILLMORE-FLOYD-GRANT- HOUSTON-HOWARD-MITCHELL-MOWER-RICHLAND-VERNON-WINNESHIEK- 511 AM CDT SUN MAY 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN. .DAY ONE...TODAY AND TONIGHT PERIODS OF THUNDERSTORMS CAN BE EXPECTED TODAY INTO TONIGHT. THERE WILL BE A THREAT FOR SEVERE WEATHER EARLY THIS MORNING...UNTIL 8 AM...AND AGAIN THIS AFTERNOON AND EARLY EVENING. LARGE HAIL... DAMAGING WINDS AND HEAVY RAIN ARE THE SEVERE THREATS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE IS A CHANCE FOR THUNDERSTORMS ON TUESDAY AND FRIDAY. SEVERE WEATHER IS NOT EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED AT TIMES...MAINLY LATE THIS AFTERNOON AND EVENING. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. MNZ079-086>088-WIZ017-029-032>034-041>044-071000- ADAMS-BUFFALO-CLARK-DODGE-JACKSON-JUNEAU-LA CROSSE-MONROE-OLMSTED- TAYLOR-TREMPEALEAU-WABASHA-WINONA- 511 AM CDT SUN MAY 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST MINNESOTA AND WEST INTO CENTRAL WISCONSIN. .DAY ONE...TODAY AND TONIGHT PERIODS OF THUNDERSTORMS CAN BE EXPECTED TODAY INTO TONIGHT. SMALL HAIL AND STRONG WIND GUSTS WILL BE POSSIBLE...ALONG WITH SOME HEAVY RAIN. SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE IS A CHANCE FOR THUNDERSTORMS ON TUESDAY AND FRIDAY. SEVERE WEATHER IS NOT EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IT NOT EXPECTED TODAY OR TONIGHT. .EMERGENCY MANAGEMENT COORDINATION... NO WEBINAR IS SCHEDULED. RIECK
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 350 AM CDT SUN MAY 6 2012 MNZ079-086>088-094-095-WIZ032>034-061000- BUFFALO-DODGE-FILLMORE-JACKSON-MOWER-OLMSTED-TREMPEALEAU-WABASHA- WINONA- 350 AM CDT SUN MAY 6 2012 ...STRONG THUNDERSTORMS MOVING ACROSS SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN... THROUGH 5 AM...SCATTERED THUNDERSTORMS WILL MOVE NORTHEAST AT 60 MPH ACROSS DODGE...MOWER...OLMSTED...WABASHA...AND WINONA COUNTIES IN SOUTHEAST MINNESOTA...AND BUFFALO...TREMPEALEAU...AND JACKSON COUNTIES IN WESTERN WISCONSIN. WIND GUSTS OF 30 TO 40 MPH AND SMALL HAIL MAY ACCOMPANY THIS STRONG THUNDERSTORM. BOYNE
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
425 AM CDT SUN MAY 06 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0422 AM HAIL ROCHESTER 44.01N 92.48W
05/06/2012 M0.25 INCH OLMSTED MN TRAINED SPOTTER
NEAR THE WALMART ON THE NORTH SIDE OF ROCHESTER
&&
BOYNEPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
450 AM CDT SUN MAY 06 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0447 AM HAIL 1 W ELEVA 44.58N 91.49W
05/06/2012 M0.25 INCH TREMPEALEAU WI TRAINED SPOTTER
&&
BOYNESPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 459 AM CDT SUN MAY 6 2012 IAZ008>010-018-019-MNZ079-086>088-094>096-WIZ017-029-032>034-041- 061100- BUFFALO-CHICKASAW-CLARK-DODGE-FILLMORE-FLOYD-HOUSTON-HOWARD-JACKSON- LA CROSSE-MITCHELL-MOWER-OLMSTED-TAYLOR-TREMPEALEAU-WABASHA- WINNESHIEK-WINONA- 459 AM CDT SUN MAY 6 2012 ...SCATTERED STRONG THUNDERSTORMS MOVING THROUGH THE AREA... THROUGH 6 AM...SCATTERED STRONG THUNDERSTORMS WILL BE FOUND GENERALLY NORTHWEST OF A LINE FROM CHARLES CITY IOWA TO BLACK RIVER FALLS WISCONSIN. THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HAIL UP TO A HALF INCH IN DIAMETER AND 30 TO 40 MPH WINDS. BOYNE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 545 AM CDT SUN MAY 6 2012 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053>055-061-061200- 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- 545 AM CDT SUN MAY 6 2012 ...SCATTERED STRONG THUNDERSTORMS MOVING THROUGH THE AREA... A LINE OF THUNDERSTORMS WILL TRACK EAST ACROSS THE AREA EARLY THIS MORNING...REACHING A MAUSTON WISCONSIN TO WEST UNION IOWA LINE BY 7 AM. HEAVY RAIN...HAIL UP TO 1/2 INCH AND WIND GUSTS OF 30 TO 40 MPH WILL ACCOMPANY THESE STORMS. A QUICK 1/4 TO 1/2 INCH OF RAIN WILL ALSO BE POSSIBLE. RIECK
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 655 AM CDT SUN MAY 6 2012 IAZ009>011-019-029-030-MNZ095-096-WIZ034-041>044-053>055-061-061300- ADAMS-ALLAMAKEE-CHICKASAW-CLAYTON-CRAWFORD-FAYETTE-FILLMORE-GRANT- HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE-MONROE-RICHLAND-VERNON- WINNESHIEK- 655 AM CDT SUN MAY 6 2012 ...STRONG THUNDERSTORMS TREKKING EAST ACROSS THE AREA... A LINE OF THUNDERSTORMS WILL REACH A BARABOO TO BOSCOBEL WISCONSIN... TO GUTTENBERG IOWA LINE BY 8 AM. HEAVY DOWNPOURS...PEA SIZED HAIL AND WIND GUSTS OF 30 TO 40 MPH WILL ACCOMPANY THESE STORMS. A QUICK 1/4 TO 1/2 INCH OF RAIN CAN ALSO BE EXPECTED. RIECK
The La Crosse radar (KARX), 78 km away, was scanning. The volume nearest the first event began at 12:15 UTC.
3 hail, 1 lightning. Local standard time, as filed.
Lightning struck and damaged a county communications tower. The lightning strike blew out the surge protectors damaging the power supply.
Quarter to golf ball sized hail fell at the intersection of County Road B and State Highway 82.
Pea to dime sized hail fell in Muscoda.
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, May 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: 373618, 373614, 373616, 373617.