A tornado outbreak occurred Arkansas to western Ohio afternoon-evening November 15, 1955. Of the 18 tornadoes, 5 were F3’s, which one of those F3s occurred in Evansville. 9 people were injured by this twister (injuries occurred in heavily damaged homes on the southeast side of Evansville) that produced F3 damage around the intersection of Weinbach & Lincoln, east of the University of Evansville. The tornado apparently touched down near Washington & Lodge & tracked over rural farmland around present-day Eastland Mall. It is unclear whether this tornado continued to track to Boonville or it lifted & then touched down in the Boonville area. F1 damage occurred on the east & south sides of Boonville. An F1 tornado tracked over southern Knox County northwest of Decker, then along the White River. F1 damage occurred in Decker.
The Evansville-Boonville supercell also produced an apparent intense downburst (+90 mph) northwest of Gentryville, Spencer County. The Decker supercell had a long history of 1.50-2.75″ hail from southeast Wayne, through Edwards County to Wabash County. The largest stones were measured near Albion at 2.75″ in diameter. The smallest stones were reported at Mt. Carmel at 1.50″ in diameter. The hail at Mt. Carmel was accompanied by an apparent damaging downburst with trees & power lines downed.
These supercells were all long-lived & significant with origins in Arkansas. Cyclical in nature, they produced large hail, tornadoes & wind all along their tracks. Even as far northeast as Trumball County, Ohio (near Youngstown), a wind gust of 91 mph was reported.
Although, surface maps show that the supercells gelled into a squall line that stretched from Kentucky to western Pennsylvania at 1:30 a.m. on November 16, all of the severe weather reports occurred as the storms occurred northwest of this area. They were likely more discrete in this severe weather outbreak zone, as well.
This storm system was a rapidly-deepening mid-latitude storm (low pressure system) with a 12 mb pressure drop in 24 hours.