Two rounds of severe storms affected parts of south-central and southeast Wisconsin on July 17th.  The first round occurred during the early afternoon hours over the counties of Dodge, Fond du Lac, Washington, and Sheboygan.  By 1250CST the storms had organized into a bow echo line extending from Lake Winnebago south to near West Bend and Hartford in Washington County and then west to the Columbus area in southeastern Columbia County.  This bow echo then moved east to out over Lake Michigan.  Dime-size hail and thunderstorm wind gusts up to 65 knots (75 mph) resulted with some of these storms.  Tree and power-line damage was reported in addition to some structural damage in Dodge and Sheboygan counties.  A semi-truck was also blown off InterState 43.  After a brief lull from thunderstorms, more storms developed during the evening hours across the remainder of south-central and southeast Wisconsin.  These storms produced dime to quarter-sized hail and wind gusts to around 52 knots (60 mph).  Mainly tree damage was reported with these storms.Interestingly, the cluster of severe storms that affected the southern parts of Lafayette and Green Counties moved east-southeast to McHenry County in northeastern Illinois.  A strong thunderstorm gust front (outflow boundary), associated with the McHenry County thunderstorms, pushed north into southeastern Wisconsin.  The gust front winds knocked down some trees in the Twin Lakes-Trevor area of western Kenosha County, and the Eagle Lake area northwest of Kansasville in south-central Racine County. No precipitation was associated with these outflow winds in Kenosha and Racine County.  Eventually this gust front merged with another south-moving frontal boundary over the central portions of Racine County.  Severe thunderstorms quickly popped up in this merger zone over central Racine County, and eventually they moved southeast through the remainder of Racine and Kenosha Counties (round #2 of severe weather for July 17th).  Synoptically, a strong, mid-level short wave trough traveled east through Wisconsin during the afternoon and evening hours. Hot temperatures in the mid-90s with dew points in the low to mid-70s, and cooler air aloft, caused extreme instability to increase through the day which allowed for rapid thunderstorm development.

Hail in FOND DU LAC, WISCONSIN
From 17-JUL-06 13:15:00 to 17-JUL-06 13:15:00 (CST)
Location: DUNDEE
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Thunderstorm Wind in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:35:00 to 17-JUL-06 13:35:00 (CST)
Location: (SBM)SHEBOYGAN CO AR
Magnitude: 53 MG
Reported by: AWOS,ASOS,MESONET,ETC

Thunderstorm Wind in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:40:00 to 17-JUL-06 13:45:00 (CST)
Location: OOSTBURG
Magnitude: 65 EG
Property damage: 100K
Reported by: LAW ENFORCEMENT

Barn reported down with horses inside northeast of Oostburg.  A roof antenna and weather station south of Sheboygan were damaged by the wind gusts.  Tree and power-line damage around the city of Sheboygan where about 12,000 customers were without power.  City work crews in Sheboygan had about 200 locations across the city where tree debris had to be cleaned up.  Clean-up and overtime costs were unknown, but were probably substantial.  Several homes had trees leaning onto roofs, and and least one vehicle was damaged when a tree fell on it.

Thunderstorm Wind in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:09:00 to 17-JUL-06 13:30:00 (CST)
Location: BEECHWOOD
Magnitude: 65 EG
Property damage: 10K
Reported by: LAW ENFORCEMENT

Trees and power lines down.

Hail in WASHINGTON, WISCONSIN
From 17-JUL-06 13:17:00 to 17-JUL-06 13:17:00 (CST)
Location: BOLTONVILLE
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in MARQUETTE, WISCONSIN
From 17-JUL-06 16:35:00 to 17-JUL-06 16:35:00 (CST)
Location: NESHKORO
Magnitude: 0.88 
Reported by: GENERAL PUBLIC

Hail in MARQUETTE, WISCONSIN
From 17-JUL-06 16:17:00 to 17-JUL-06 16:17:00 (CST)
Location: WESTFIELD
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Hail in GREEN LAKE, WISCONSIN
From 17-JUL-06 16:55:00 to 17-JUL-06 16:55:00 (CST)
Location: BERLIN
Magnitude: 0.88 
Reported by: GENERAL PUBLIC

Thunderstorm Wind in DODGE, WISCONSIN
From 17-JUL-06 13:05:00 to 17-JUL-06 13:05:00 (CST)
Location: LOMIRA
Magnitude: 56 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT

Trees and power-lines down.  Garage door blown in.

Hail in FOND DU LAC, WISCONSIN
From 17-JUL-06 12:48:00 to 17-JUL-06 12:48:00 (CST)
Location: ROSENDALE
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in FOND DU LAC, WISCONSIN
From 17-JUL-06 13:05:00 to 17-JUL-06 13:05:00 (CST)
Location: CAMPBELLSPORT
Magnitude: 56 EG
Property damage: 3K
Reported by: TRAINED SPOTTER

Trees down.

Hail in COLUMBIA, WISCONSIN
From 17-JUL-06 18:30:00 to 17-JUL-06 18:30:00 (CST)
Location: CAMBRIA
Magnitude: 0.75 
Reported by: FIRE DEPT/RESCUE SQUAD

Hail in COLUMBIA, WISCONSIN
From 17-JUL-06 17:50:00 to 17-JUL-06 17:50:00 (CST)
Location: FRIESLAND
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in FOND DU LAC, WISCONSIN
From 17-JUL-06 18:50:00 to 17-JUL-06 18:50:00 (CST)
Location: CAMPBELLSPORT
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in SHEBOYGAN, WISCONSIN
From 17-JUL-06 18:55:00 to 17-JUL-06 18:55:00 (CST)
Location: SHEBOYGAN FALLS
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in WASHINGTON, WISCONSIN
From 17-JUL-06 20:18:00 to 17-JUL-06 20:18:00 (CST)
Location: HARTFORD
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in OZAUKEE, WISCONSIN
From 17-JUL-06 19:35:00 to 17-JUL-06 19:35:00 (CST)
Location: BELGIUM
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in GREEN, WISCONSIN
From 17-JUL-06 20:20:00 to 17-JUL-06 20:20:00 (CST)
Location: BROWNTOWN
Magnitude: 52 EG
Property damage: 15K
Reported by: TRAINED SPOTTER

Trees and some power-lines down in the area southwest through southeast of Browntown, including Browntown.

Thunderstorm Wind in KENOSHA, WISCONSIN
From 17-JUL-06 21:40:00 to 17-JUL-06 21:45:00 (CST)
Location: TWIN LAKES
Magnitude: 52 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT

Trees down.

Thunderstorm Wind in LAFAYETTE, WISCONSIN
From 17-JUL-06 20:17:00 to 17-JUL-06 20:17:00 (CST)
Location: SOUTH WAYNE
Magnitude: 52 EG
Property damage: 2K
Reported by: TRAINED SPOTTER

Large trees and tree limbs down.

Thunderstorm Wind in WALWORTH, WISCONSIN
From 17-JUL-06 22:12:00 to 17-JUL-06 22:12:00 (CST)
Location: ZENDA
Magnitude: 52 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT

Trees down.

Thunderstorm Wind in RACINE, WISCONSIN
From 17-JUL-06 22:50:00 to 17-JUL-06 22:50:00 (CST)
Location: RACINE
Magnitude: 52 EG
Property damage: 5K
Reported by: LAW ENFORCEMENT

Trees down.

Thunderstorm Wind in KENOSHA, WISCONSIN
From 17-JUL-06 22:35:00 to 17-JUL-06 22:55:00 (CST)
Location: KENOSHA
Magnitude: 56 EG
Property damage: 20K
Reported by: LAW ENFORCEMENT

Areas of toppled trees and broken tree branches, along with power-line damage, reported across the cities of Kenosha and Pleasant Prairie.

Hail in MARQUETTE, WISCONSIN
From 17-JUL-06 16:17:00 to 17-JUL-06 16:17:00 (CST)
Location: BUDSIN
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:09:00 to 17-JUL-06 13:09:00 (CST)
Location: CASCADE
Magnitude: 56 EG
Property damage: 10K
Reported by: GENERAL PUBLIC

Trees and power-lines down.

Hail in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:39:00 to 17-JUL-06 13:39:00 (CST)
Location: KOHLER
Magnitude: 0.88 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in SHEBOYGAN, WISCONSIN
From 17-JUL-06 13:40:00 to 17-JUL-06 13:40:00 (CST)
Location: SHEBOYGAN FALLS
Magnitude: 61 EG
Property damage: 2K
Reported by: TRAINED SPOTTER

Semi truck blown over about 1 mile north of Interstate 43 interchange with CTH V.  Slight damage.

Thunderstorm Wind in RACINE, WISCONSIN
From 17-JUL-06 22:00:00 to 17-JUL-06 22:00:00 (CST)
Location: KANSASVILLE
Magnitude: 56 EG
Property damage: 10K
Reported by: LAW ENFORCEMENT

Tree and power-line damage in the Eagle Lake area northwest of Kansasville.