Tri-State Tornado

1. Wednesday, March 18, 1925 Tri-State Tornado

2. Deadliest tornado in U.S. history 747 fatalities & 2,298 were injured Continuous ≥219 mile (≥352 km) track was the longest ever recorded in the world Although not officially rated by NOAA, recognized by most experts as an F5 tornado(Fujita scale) Tri-State Tornado

4. Tri-State Tornado One tornado or a series? • Uncertainty whether the event was one continuous tornado or a tornado family • Doubts because: • Sparse quality of tornado data • Lack of other tornadoes approaching this path length and duration • Meteorological theory on tornadoes and supercell morphology suggests such • duration was improbable • Several historically very long track tornadoes have been subsequently found to be • tornado families • Woodward, Oklahoma tornado family of April 1947 • Charleston-Mattoon, Illinois tornado family of May 1917 • In the past several years, some very long track tornadoes • and supercells have occurred • Ongoing new research finds: • No break in the path • Tornado began approximately 15 mi (24 km) farther W than previously thought • Total path length now 234 miles (377 km)

5. Part of a larger tornado outbreak • Several other destructive tornadoes the same day • Tennessee, Kentucky, and Indiana, Alabama and Kansas • Makes the Tri-State Outbreak : • the deadliest tornado outbreak • the deadliest tornado day (March 18th) • the deadliest tornado year (1925) in U.S. history Tri-State Tornado Outbreak

6. 3 states, 13 counties, and more than 19 communities, four of which were effectively effaced (several of these and other rural areas never recovered), were in the path Record 3.5 hour duration ~15,000 homes were destroyed Total damage est. at $16.5 million; adjusted toll is approximately $1.4 billion (1997) 9 schools across three states were destroyed 69 students were killed More schools were destroyed and more students killed (as well as the single school record of 33 deaths in De Soto, Illinois) than in any other tornado in U.S. history Tri-State Tornado

7. Interesting that occurrence was nearly coincidental with the track of the surface low Goes against conventional thinking that while it is not uncommon for a tornado to occur in conjunction with the surface low, the most violent ones actually occur in the warm sector of the storm—well south and east of the low’s track Different

8. 3 states affected (Missouri, Illinois, Indiana) 13 counties affected 19+ communities affected 219 mile path length 3/4 mile average path width (some accounts of 1 mile wide—a record width) 3 1/2 hours of continuous devastation 1:01 p.m.—tornado touched down 3 miles NNW of Ellington, Missouri 4:30 p.m.—tornado dissipated about 3 miles SW of Petersburg, Indiana N 69° E heading maintained for 183 of the 219 miles 62 mph average speed 73 mph record speed between Gorham & Murphysboro F5 tornado on the Fujita Scale, with winds perhaps in excess of 300 mph 28.87" lowest pressure measured on a barograph trace at the Old Ben Coal Mine in West Frankfort, Illinois 695 deaths—a record for a single tornado 234 deaths in Murphysboro—a record for a single community from such a disaster 33 deaths at the De Soto school—a record for such a storm (only bombings and gas explosions have taken higher school tolls) 2,027 injuries 15,000 homes destroyed Statistics