Several lines of severe thunderstorms with damaging winds affected South Central Wisconsin during the late evening hours of May 19th, lasting into the early morning hours of May 20th. Some structural damage occurred, with many trees and power lines downed by winds that were sustained for 10 to 20 minutes at a time up to 44 mph (38 knots),  and gusting to 60 mph (52 knots). The lines of severe storms were moving around 40 knots (46 mph) driven a by a 50-60 knot low-level jet ahead of one of a series of a short-wave impulses that crossed the region. The combination of actual storm speed and the momentum transfer of the strong low-level jet winds being brought down to the surface with the storm precipitation produced the damaging wind gusts.

Thunderstorm Wind in SAUK, WISCONSIN
From 19-MAY-13 23:56:00 to 20-MAY-13 00:05:00 (CST-6)
Location: REEDSBURG
Magnitude: 56.00 EG
Property damage: 10.00K
Reported by: Law Enforcement

Law enforcement officials reported trees downed by powerful thunderstorm winds that gusted to an estimated 65 mph (56 knots) along a path from Reedsburg to 3 miles wesdt of Lake Delton.

Thunderstorm Wind in COLUMBIA, WISCONSIN
From 20-MAY-13 00:14:00 to 20-MAY-13 00:14:00 (CST-6)
Location: LODI
Magnitude: 52.00 MG
Reported by: Mesonet

A mesonet site located at Lodi Middle School recorded a 60 mph (52 knot) thunderstorm wind gust.

Thunderstorm Wind in ROCK, WISCONSIN
From 19-MAY-13 20:05:00 to 19-MAY-13 20:05:00 (CST-6)
Location: ORFORDVILLE
Magnitude: 65.00 EG
Property damage: 20.00K
Reported by: Department of Highways

Rock County Highway Department workers reported the intersection of State Highway 11 and State Highway 213 in Orfordville was closed due to trees and power lines downed by powerful thunderstorm winds that gusted to an estimated 75 mph (65 knots).

Thunderstorm Wind in ROCK, WISCONSIN
From 19-MAY-13 20:00:00 to 19-MAY-13 20:05:00 (CST-6)
Location: AFTON
Magnitude: 65.00 EG
Property damage: 50.00K
Reported by: Law Enforcement

Law enforcement officials reported many trees and power lines downed by powerful thunderstorm winds that gusted to an estimated 75 mph (65 knots) along a path from 5 miles east of Beloit to Afton. One tree went through the roof of a home 3 miles northwest of Beloit.

Thunderstorm Wind in SAUK, WISCONSIN
From 19-MAY-13 23:37:00 to 19-MAY-13 23:37:00 (CST-6)
Location: LONE ROCK AIRPORT
Magnitude: 52.00 MG
Reported by: ASOS

The Lone Rock Airport (KLNR) ASOS recorded a thunderstorm wind gust of 60 mph (52 knots).

Thunderstorm Wind in IOWA, WISCONSIN
From 19-MAY-13 23:40:00 to 19-MAY-13 23:40:00 (CST-6)
Location: CLYDE
Magnitude: 56.00 EG
Property damage: 10.00K
Reported by: Trained Spotter

A trained spotter reported trees downed by powerful thunderstorm winds that gusted to an estimated 65 mph (56 knots) about 3 miles south-southwest of Lone Rock. One of the downed trees blocked State Highway 130 for a time.

Thunderstorm Wind in MARQUETTE, WISCONSIN
From 20-MAY-13 00:31:00 to 20-MAY-13 00:37:00 (CST-6)
Location: OXFORD
Magnitude: 56.00 EG
Property damage: 10.00K
Reported by: Law Enforcement

Law enforcement officials reported trees and power lines downed by powerful thunderstorm winds that gusted to an estimated 65 mph (56 knots) along a path from 1 mile northeast of Oxford to 2 miles south of Westfield.

Thunderstorm Wind in SAUK, WISCONSIN
From 19-MAY-13 23:45:00 to 19-MAY-13 23:50:00 (CST-6)
Location: SPRING GREEN
Magnitude: 56.00 EG
Property damage: 40.00K
Reported by: Law Enforcement

Law enforcement officials reported trees downed by powerful thunderstorm winds that gusted to an estimated 65 mph (56 knots) in Spring Green. One building was damaged by a falling tree.