Several clusters of severe thunderstorms moved southeast through parts of south-central and southeast Wisconsin during the late morning and early afternoon hours. They produced predominately damaging, large hail stones, ranging in diameter from 3/4 inch on up to an incredible 3.75 inches!  Most reports indicated that hailstones were in the 1 to 2 inch diameter range, and at many locations the hailstones left the ground white.  Isolated wind damage was noted in Columbia County where large trees and some power lines were toppled near Friesland.The city of Watertown, which straddles the Dodge and Jefferson County line, sustained the worst hail damage. Hail fell for about 10 to 15 minutes, with the largest stones of 2.50 to 3.75 inches falling for about 1 to 2 minutes. One person was injured when the large hail stones landed on their head.  Roughly 7500 motor vehicles were damaged - namely broken windows and  numerous dents in the sheet metal.  It was noted that some of the hood dents looked as if a person had driven their fist into the sheet metal!  Seven (7) greenhouses belonging to a city florist received serious glass damage, as well as plant damage. In addition, many skylight windows in residential homes and businesses were shattered. On the north side of Watertown, the large hail stripped bark off trees.  Local residents mentioned that they had never seen anything like this hailstorm.  The ground was white, and the hail didn't melt completely for several hours. Many motor vehicles in the Waterford area of western Racine County sustained hail damage.  In the city of Brookfield, a moving car was struck by lightning. The driver was unhurt, but the vehicle's electrical system was fried, a rear window was shattered, the two rears tires were left in shreds, and holes 6 inches deep and 3 feet wide were blown in the pavement. Small stream and urban flooding was noted in the city of Kenosha.  Pike Creek flowed over its banks in Washington Park.  Rainfall totals of 1 to 2 inches in 1 hour were noted across parts of southeast Wisconsin as the storms rolled southeastward.Synoptically, low pressure moved southeast from the South Dakota-North Dakota border, with a warm front extending southeast through southern Wisconsin to northern Indiana.  A strong low-level jet pumped warm, moist, unstable air directly into southern Wisconsin up over the warm front position. Upper level lapse rates became steep as colder air moved in from the northwest. No thunderstorm activity was noted west of a line from Portage (Columbia Co.) to Waterloo (Jefferson Co.) to Delevan (Walworth Co.).

Hail in JEFFERSON, WISCONSIN
From 14-MAY-01 10:21:00 to 14-MAY-01 10:21:00 (CST)
Location: SULLIVAN
Magnitude: 1.50 
Reported by: GOVT OFFICIAL

Hail in MARQUETTE, WISCONSIN
From 14-MAY-01 09:50:00 to 14-MAY-01 09:50:00 (CST)
Location: WESTFIELD
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in GREEN LAKE, WISCONSIN
From 14-MAY-01 10:35:00 to 14-MAY-01 10:35:00 (CST)
Location: PRINCETON
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in JEFFERSON, WISCONSIN
From 14-MAY-01 09:59:00 to 14-MAY-01 09:59:00 (CST)
Location: JOHNSON CREEK
Magnitude: 0.88 
Reported by: LAW ENFORCEMENT

Hail in GREEN LAKE, WISCONSIN
From 14-MAY-01 10:50:00 to 14-MAY-01 10:50:00 (CST)
Location: MARKESAN
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in WAUKESHA, WISCONSIN
From 14-MAY-01 10:30:00 to 14-MAY-01 10:30:00 (CST)
Location: EAGLE
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in RACINE, WISCONSIN
From 14-MAY-01 10:30:00 to 14-MAY-01 10:30:00 (CST)
Location: BURLINGTON
Magnitude: 1.50 
Reported by: TRAINED SPOTTER

Hail in KENOSHA, WISCONSIN
From 14-MAY-01 11:19:00 to 14-MAY-01 11:19:00 (CST)
Location: SILVER LAKE
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in WALWORTH, WISCONSIN
From 14-MAY-01 10:45:00 to 14-MAY-01 10:45:00 (CST)
Location: EAST TROY
Magnitude: 0.88 
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in COLUMBIA, WISCONSIN
From 14-MAY-01 11:15:00 to 14-MAY-01 11:15:00 (CST)
Location: FRIESLAND
Magnitude: 52 E
Reported by: TRAINED SPOTTER

Hail in DODGE, WISCONSIN
From 14-MAY-01 11:06:00 to 14-MAY-01 11:06:00 (CST)
Location: BEAVER DAM
Magnitude: 0.88 
Reported by: LAW ENFORCEMENT

Hail in DODGE, WISCONSIN
From 14-MAY-01 11:40:00 to 14-MAY-01 11:40:00 (CST)
Location: ALDERLEY
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Hail in WAUKESHA, WISCONSIN
From 14-MAY-01 11:43:00 to 14-MAY-01 11:48:00 (CST)
Location: OCONOMOWOC
Magnitude: 1.75 
Reported by: LAW ENFORCEMENT

Hail in WAUKESHA, WISCONSIN
From 14-MAY-01 12:04:00 to 14-MAY-01 12:04:00 (CST)
Location: NORTH PRAIRIE
Magnitude: 1.75 
Reported by: NWS EMPLOYEE(OFF DUTY)

Hail in WAUKESHA, WISCONSIN
From 14-MAY-01 12:15:00 to 14-MAY-01 12:15:00 (CST)
Location: NEW BERLIN
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in JEFFERSON, WISCONSIN
From 14-MAY-01 11:32:00 to 14-MAY-01 11:32:00 (CST)
Location: WATERTOWN
Magnitude: 3.75 
Property damage: 300K
Reported by: TRAINED SPOTTER

Hail in JEFFERSON, WISCONSIN
From 14-MAY-01 11:50:00 to 14-MAY-01 11:50:00 (CST)
Location: CONCORD
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in MILWAUKEE, WISCONSIN
From 14-MAY-01 12:10:00 to 14-MAY-01 12:10:00 (CST)
Location: WEST ALLIS
Magnitude: 0.75 
Reported by: NWS EMPLOYEE(OFF DUTY)

Lightning in WAUKESHA, WISCONSIN
From 14-MAY-01 12:50:00 to 14-MAY-01 12:50:00 (CST)
Location: BROOKFIELD
Property damage: 3K
Reported by: NEWSPAPER

Flood in KENOSHA, WISCONSIN
From 14-MAY-01 13:30:00 to 14-MAY-01 15:30:00 (CST)
Location: KENOSHA
Reported by: NEWSPAPER

Hail in DODGE, WISCONSIN
From 14-MAY-01 09:29:00 to 14-MAY-01 09:29:00 (CST)
Location: RANDOLPH
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in DODGE, WISCONSIN
From 14-MAY-01 11:28:00 to 14-MAY-01 11:28:00 (CST)
Location: WATERTOWN
Magnitude: 2.50 
Property damage: 150K
Reported by: LAW ENFORCEMENT

Hail in RACINE, WISCONSIN
From 14-MAY-01 12:22:00 to 14-MAY-01 12:22:00 (CST)
Location: WATERFORD
Magnitude: 1.50 
Property damage: 50K
Reported by: TRAINED SPOTTER

Hail in KENOSHA, WISCONSIN
From 14-MAY-01 12:45:00 to 14-MAY-01 12:45:00 (CST)
Location: TWIN LAKES
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in KENOSHA, WISCONSIN
From 14-MAY-01 12:55:00 to 14-MAY-01 12:55:00 (CST)
Location: SOMERS
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT