SUPER TORNADO OUTBREAK 148 TORNADOES IN 18 HOURS 315-330 DEATHS $3.5 BILLION (2005 DOLLARS) APRIL 3-4, 1974 Walter Hays, Global Alliance for Disaster Reduction, University of North Carolina, USA

CAUSE A powerful spring-time low pressure system that developed across the North American Interior Plains on April 1st was intensified when it collided with a system of very moist cold air creating a large contrast in temperature.

SUPER TORNADO OUTBEAK: APRIL 3-4, 1974

STATES IMPACTED BY THE 1974 TORNADO OUTBREAK: APRIL 3-4 Illinois Indiana Ohio Kentucky Michigan Tennessee

STATES IMPACTED BY THE 1974 TORNADO OUTBREAK: APRIL 3-4 Alabama Mississippi Georgia North Carolina Virginia West Virginia New York

DIMENSIONS OF THE TORNADO OUTBREAK DURATION: 18 HOURS MAXIMUM: F5 AREA OF IMPACT: 13 STATES DAMAGE: $3.5 BILLION (2005 DOLLARS)

DISTRIBUTION OF STORMS IN THE 1974 OUTBREAK 6 F5’s (Including the Xenia storm) 24 F4’s 34 F3’s 32 F2’s 33 F1’s

XENIA, OHIO: ONE OF THE WORST TORNADOES IN HISTORY The tornado formed near Bellbrook, Ohio at 4:30 pm EDT, and reached Xenia as a F5 storm at 4:40 pm.

THE TORNADO DESTROYED XENIA

NATURAL HAZARDS FOR WHICH EVACUATION IS TYPICAL FLOODS GOAL: MOVE PEOPLE OUT OF HARM’S WAY HURRICANES ADVANCE WARNING FOR TORNADOES IS INADEQUATE EXCEPT FOR GOING TO A SAFE ROOM IN THE HOUSE TYPHOONS TSUNAMIS VOLCANIC ERUPTIONS WILDFIRES