A mesoscale convective system over the Dakotas moved east-southeast through Wisconsin. It was aided by a strong short wave trough aloft and a cold front dropping southeast.
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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 MKX wrote it up.
A mesoscale convective system over the Dakotas moved east-southeast through Wisconsin. It was aided by a strong short wave trough aloft and a cold front dropping southeast. Short bowing segments of storms generated damaging winds, large hail, and heavy rains that led to localize flash flooding.
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 Milwaukee, WI wrote its last area forecast discussion before the first event at Jul 3, 3:18 AM CST, 7 hours 52 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 418 AM CDT TUE JUL 3 2007 .SHORT TERM... WARM ADVECTION IS SUPPORTING BKN CLOUD COVER AND ISOLD SHOWERS EARLY THIS AM. THE WAA WILL CONTINUE TODAY AHEAD OF A WEAK SHORTWAVE TROUGH AND SFC TROUGH...WHICH IS PROGGED TO REACH THE MS RIVER BY 00Z WED. ALTHOUGH MODELS SHOW ONLY WEAK SFC CONVERGENCE ALONG SFC TROUGH AND WEAK SYNOPTIC SCALE LIFT...THE NAM...GFS...AND CRAS MODELS ALL SUPPORT WIDESPREAD CONVECTION BEGINNING POSSIBLY THIS AFTERNOON IN CENTRAL OR WRN WI AND THEN PROGRESS ACROSS ALL OF SRN WI TNT. INITIATION COULD BE AIDED BY OUTFLOW BOUNDARY OR CONTINUING CONVECTION FROM ONGOING MCS OVER ND. STRONGLY VEERING WIND PROFILES WILL YIELD 0-3 KM SRH AROUND 200 M2/S2 IN WRN CWA BY 00Z WHILE 0-6 KM SHEAR INCREASES TO 35 KTS. 80/66 PARCEL WILL GIVE MLCAPE VALUES AROUND 1000 J/KG OR POSSIBLY MORE. MODE OF CONVECTION BASED ON LARGE MODEL QPF WOULD SUGGEST A SQUALL LINE BUT WEAK LOW LEVEL CONVERGENCE AND WEAK LIFT COULD RESULT IN MORE SCT CONVECTION WITH SUPERCELLS POSSIBLE. CANNOT COMPLETELY RULE OUT A TORNADO THREAT WITH MLLCLS FCST AROUND 1.0-1.2 KM ALTHOUGH 0-1 KM SHEAR OF 10 KTS IS WEAK. MID LEVEL LAPSE RATES REMAIN POOR OVER SRN WI AND THIS COULD LIMIT HAIL AND WIND THREATS. WILL NOT MENTION SVR IN THE ZFP FOR NOW BUT HIGHLIGHT SEVERE THREAT IN HWO. SFC TROUGH TO SLOWLY MOVE ACROSS SRN WI ON WED WITH REDEVELOPMENT POSSIBLE IN FAR SRN WI IN THE AFTERNOON. OTHER ISOLD DEVELOPMENT WILL BE POSSIBLE OVER THE REMAINDER OF THE AREA AS CIN IS REMOVED AND A WEAK SHORTWAVE WITHIN NW FLOW MOVES TOWARD THE AREA. THE SAME SCENARIO THEN SETS UP FOR THU AS WELL WITH SLIGHT CHANCES FCST. THE VARIOUS GUIDANCE TEMPS IN GOOD AGREEMENT THROUGH THU AND FCST IS SIMILAR. DO EXPECT LAKE BREEZES EVERDAY AT LEAST THROUGH FRI BUT REMAINING CLOSE TO SHORELINE ON MOST DAYS. .LONG TERM... ECMWF AND GFS SUPPORTING A VERY WARM TO HOT WLY FLOW FOR SAT AND SUN WITH 1000-500 MB THICKNESSES FROM 576-582 DM. A COLD FRONT TO THEN BRING CHANCES OF STORMS BY SUN NT OR MON. && .AVIATION...EXPECT MAINLY ISOLATED SHOWERS FROM MID LEVEL CLOUDS THIS MORNING WITH WARM AIR ADVECTION. BEST LOW LEVEL CONVERGENCE WILL BE TO THE NORTH OF THE FORECAST AREA. FORECAST SOUNDINGS SHOW MID CLOUDS TO SCATTERED OUT THIS AFTERNOON WITH CUMULUS DEVELOPING. UNSTABLE AIRMASS ESPECIALLY OVER SOUTHWEST WI THIS AFTERNOON AND EVEN. SOME SCATTERED THUNDERSTORM POTENTIAL THIS AFTERNOON. HOWEVER THUNDERSTORMS MOST LIKELY TONIGHT AHEAD OF AN ADVANCING COLD FRONT. MAINLY VFR CIGS AND VSBYS...EXCEPT IN THUNDERSTORMS. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && 20/20/06
HAZARDOUS WEATHER OUTLOOK...UPDATE NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 1130 AM CDT TUE JUL 3 2007 WIZ046-047-051-052-056>060-062>072-041000- MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE- WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE- LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA- 1130 AM CDT TUE JUL 3 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN. .DAY ONE...THIS AFTERNOON AND TONIGHT A SLIGHT RISK OF SEVERE THUNDERSTORMS WILL EXIST THIS AFTERNOON AND ESPECIALLY TONIGHT WITH THE POTENTIAL FOR DAMAGING WINDS AND LARGE HAIL. AN ISOLATED TORNADO IS POSSIBLE MAINLY OVER SOUTH CENTRAL WISCONSIN. VERY HEAVY RAINS LIKELY WITH SOME STORMS. THE AIRMASS WILL BECOME MORE UNSTABLE THIS AFTERNOON AND TONIGHT AHEAD OF AN ADVANCING COLD FRONT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE IS A CHANCE OF THUNDERSTORMS ON INDEPENDENCE DAY...AND AGAIN SUNDAY NIGHT AND MONDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND TONIGHT. LMZ643>646-665-041000- SHEBOYGAN TO PORT WASHINGTON- PORT WASHINGTON TO NORTH POINT LIGHTHOUSE- NORTH POINT LIGHTHOUSE TO WIND POINT- WIND POINT TO WINTHROP HARBOR ILLINOIS- WISCONSIN ADJACENT OPEN WATERS OF LAKE MICHIGAN TO MID LAKE- 1130 AM CDT TUE JUL 3 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN. .DAY ONE...THIS AFTERNOON AND TONIGHT A SLIGHT RISK OF SEVERE THUNDERSTORMS WILL EXIST LATE THIS AFTERNOON AND ESPECIALLY TONIGHT WITH THE POTENTIAL FOR DAMAGING WINDS AND LARGE HAIL. THE AIRMASS WILL BECOME MORE UNSTABLE THIS AFTERNOON AND TONIGHT AHEAD OF AN ADVANCING COLD FRONT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE IS A CHANCE OF THUNDERSTORMS ON INDEPENDENCE DAY...AND AGAIN SUNDAY NIGHT AND MONDAY. WWW.WEATHER.GOV/MKX
The Milwaukee radar (KMKX), 67 km away, was scanning. The volume nearest the first event began at 17:12 UTC.
11 thunderstorm wind, 3 lightning, 1 hail, 1 flash flood. Local standard time, as filed.
Lightning struck an 150-year-old building's TV antenna, resulting in an attic fire. Damage was limited to the attic and one apartment.
Lightning struck a home in Slinger, and the resultant fire damaged only the living room and electrical wiring.
Slow moving thunderstorm cells trained over the same area northeast of Harrisville near and along CTH E (3 NE Harrisville or about 2.7 miles west-southwest of Budsin), resulting in a flash flood. Water depths on road surfaces reached 2 to 3 feet, and water entered basements of several homes. Damage occurred to personal property in the basements. WSR-88D Doppler radar rainfall estimates were on the order of 3 to 4 inches.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled large trees. A couple power-lines came down with tree debris.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled large trees. A couple power-lines came down with tree debris.
Powerful downburst winds gusting to around 52 knots (60 mph) toppled several large trees.
Powerful downburst thundestorm winds gusting to a measured 52 knots (60 mph) gust at the Lone Rock Airport (LNR) ASOS unit toppled large trees. A couple power-lines came down with tree debris.
Powerful downburst thundestorm winds gusting to around 52 knots (60 ph) toppled several large trees.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled large trees. Seveal power-lines came down with tree debris.
Powerful downburst thundestorm winds gusting to around 65 knots (75 mph) toppled hundreds of large trees in a forested area. Several power-lines came down with tree debris. One large tree fell onto a vehicle. Two small sheds were destroyed by the winds, and one home sustained window damage.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled large trees. Seveal power-lines came down with tree debris.
Powerful downburst thundestorm winds gusting to around 56 knots (65 mph) toppled several large trees. Several power-lines came down with tree debris.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled several large trees and a couple power-lines came down due to tree debris.
Powerful downburst thundestorm winds gusting to around 52 knots (60 mph) toppled several large trees.
A 2-story Janesville home was destroyed by a fire after ligntning struck it.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2007Every state in 2007This day in weather historyWarnings in Wisconsin, July 2007
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: 49314, 49315, 49299, 49300, 49302, 49303, 49312, 49301, 49309, 49305, 49307, 49306, 49308, 49310, 49311, 49316.