NOAA's National Weather Service Weather Forecast Office

In summary:

Deaths: 1
Injuries: 14
Tornado path length: 6.5 miles (100 yds wide)
Tornado intensity: F4
Time: 5:39 PM - 5:51 PM

A VIOLENT TORNADO PASSED JUST TO THE SOUTHEAST OF WALES WISCONSIN DURING THE LATE AFTERNOON ON APRIL 27 1984. THE TORNADO KILLED 1 PERSON AND INJURED 14 OTHER PEOPLE WHILE CREATING EXTENSIVE DAMAGE.

A STRONG FRONTAL BOUNDARY INTERACTING WITH A WARM...MOIST AND UNSTABLE AIRMASS HELPED TO DEVELOP SCATTERED THUNDERSTORMS ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS. ONE OF THESE STORMS ACROSS SOUTHEASTERN WISCONSIN BECOME TORNADIC ON THE AFTERNOON OF APRIL 27 1984.

A SUPERCELL DEVELOPED ACROSS SOUTH CENTRAL WISCONSIN AND PUSHED INTO SOUTHWESTERN WAUKESHA COUNTY AROUND 530 PM CDT. THE STORM SPAWNED A TORNADO AT THE INTERSECTION OF COUNTY ROAD E AND COUNTY ROAD D... ABOUT TWO AND A HALF MILES SOUTH SOUTHWEST OF WALES WISCONSIN...OR ABOUT 20 MILES WEST OF MILWAUKEE AT 539 PM CDT.

THE TORNADO CONTINUED TO INTENSIFY AS IT MOVED NORTHEAST INTO THE FAR SOUTHEASTERN AREAS OF WALES MINUTES AFTER DEVELOPING. THE TORNADO THEN CROSSED US 18 AT COUNTY ROAD G AROUND 547 PM CDT. IT CONTINUED TO PRESS NORTH NORTHEAST, FINALLY DISSIPATING JUST SOUTHWEST OF I94 AT COUNTY ROAD SS IN THE SOUTHWESTERN CORNER OF TOWN OF PEWAUKEE AROUND 551 PM CDT.

THE TORNADO LEFT A SIX AND A HALF MILE LONG AND A 100 YARD WIDE PATH OF DESTRUCTION JUST SOUTH... SOUTHEAST...AND EAST OF WALES. THE HARDEST HIT AREA WITHIN THE TORNADO/S PATH WAS THE DOVER BAY SUBDIVISION IN DELAFIELD. ONE WOMAN WAS KILLED AND 14 OTHER PEOPLE WERE INJURED.

IT WAS LATER DETERMINED THROUGH DAMAGE SURVEYS THAT THE WALES TORNADO WAS A VIOLENT F4...THE SECOND HIGHEST LEVEL ON THE FUJITA TORNADO SCALE.

...A COMPREHENSIVE SUMMARY OF THE FUJITA SCALE...

...WIND SPEEDS ARE ESTIMATED FROM DAMAGE SURVEYS...

F1...40-72 MPH
F2...73-112 MPH
F3...113-157 MPH
F4...207-260 MPH
F5...261-318 MPH