Elma-Lawler-Waucoma, IA F4 Tornado – July 12, 1971

SPC Stats:

Path length: 10.9 miles

Width:  1320 yards

Fatalities:  0

Injuries:  8

Rating:  F4

Counties:  Howard, Chickasaw, Fayette

Per the SPC Database, there were 5 tornadoes on July 12, 1971....all in Iowa.  The strongest was rated F4.  It began in Howard County near Elma and traveled close to 30 miles into Chickasaw County and ending in Fayette County near Waucoma.  

The SPC database entry for this event only has a path length of 10.9 miles.  Storm Data and Grazulis all show a length at 30 miles.  When you add up the segments in NCDC you get a path length of 30.9 miles.  Plotting the path, 30 miles appears to be correct.

Not a lot of information on this tornado from Storm Data.  They state, "Nearly 50 farmsteads extensively damaged."  Grazulis adds, "Three homes and barns swept away."   There were 8 injuries reported.

Storm Data Entry

The Storm Data Entry states the location as Elma, Howard County into NE Chickasaw County.  There is an entry for Fayette County under “windstorm”. 

Tornado damage to north of Lawler and Waucoma.  Nearly 50 farmsteads extensively damaged.

Additional information from Thomas Grazulis in Significant Tornadoes

  • Moved SE from 2 miles West of Elma, passing 2 miles S of that town to Lawler and to SW of Waucoma.
  • Three homes and barns swept away.

Tornado Path

Discrepancies:

We gathered information for this event from the SPC & NCDC Databases, the July 1971 Storm Data Publication and Thomas Grazulis in Significant Tornadoes and found the following differences:

Path Length:

  • SPC has a path length of 10.9 miles.
  • NCDC has a path length of 30.9 miles.
  • Both Grazulis and Storm Data have a path length of 30 miles.

Max Width:

  • Grazulis has a width of 400 yards.
  • Remaining sources list the width at 1320 yards.

Counties:

  • Storm Data doesn't mention Fayette County in the tornado entry for this event.
  • Remaining sources have all 3 counties (Howard, Chickasaw and Fayette). 

Sources:

The Storm Prediction Center

NCDC Storm Events Database

July 1971 Storm Data Publication

newspapers.com

Grazulis, Thomas P. (1993). Significant Tornadoes 1680-1991: A Chronology and Analysis of Events. St. Johnsbury, VT: The Tornado Project of Environmental Films. Page 1126.