Prairieburg/Worthington, IA F4 Tornado

Per the SPC Database, 14 tornadoes occurred on March 13, 1990 in the state of Iowa.  The strongest, an F4 traveled 19 miles from Prairieburg in Linn County to Worthington in Dubuque County.  The max width was 200 yards. There were no injuries or fatalities.

This images of the narrative were extracted from the historical 3/1990 Storm Data Publication.

Sources:

The Storm Prediction Center

NCDC Storm Events Database

3/1990 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 1292.