EF3 tornado in Lawrence County, Indiana

This brief but powerful tornado had a steady track to the east-northeast, creating damage consistent of an EF3 strength tornado. A rating of EF3 corresponds with winds of 136 to 165 MPH. The maximum width of the tornado was approximately 1/8 mile. It completely destroyed the above ground portions of two homes, seriously damaged a trailer home, and created lesser damage to two other homes. It picked a full size school bus up, turned it around and onto its side, and moved it uphill onto the foundation of what had been an occupied home. The damage estimate is very rough.

By late morning a warm front stretched approximately from low pressure over northeast Missouri through central Illinois to between Indianapolis and Fort Wayne, Indiana while the cold front trailed from the low into Oklahoma. At 1040 EST tornado watch number 49 was issued for much of western Indiana, much of Illinois, and locations south, effective until 1600 EST. National Weather Service radar showed scattered storms in the watch area in Indiana, better organized storms firing up over eastern Iowa and western Illinois, and an area of rain north of the warm front.

At 1400 EST radar showed a broken line of storms with isolated supercells and line segments extending from northern Indiana south-southwestward through southern Indiana into western Kentucky with an eastward movement at 40-45 knots along central and northern portions of the line. The thermodynamic environment was marginally unstable but becoming more unstable with time. Supporting factors for severe weather were: large-scale atmospheric ascent, forcing associated with an ejecting short wave trough, significant shear, and increasing sunshine along and behind the warm front as it lifted north.

At 1343 EST the first severe weather report occurred with a measured thunderstorm wind gust of 91 MPH in Vincennes in Knox county. An additional tornado watch, watch number 50, was issued at 1355 EST to cover the rest of Indiana east of watch number 49. At this point 90+ knot mid-level winds and 55+ knot 850 millibar winds were across the region. Portions of the watches were canceled starting shortly before 1600 EST.

By the end of the severe weather episode an EF3 tornado had touched down in Lawrence County just west of Bedford. Portions of Daviess county experienced wind gusts of 80 to 90 MPH, while Tippecanoe, Clinton and Howard Counties had gusts from 60 to 70 mph. Significant damage occurred to several homes and farms in Lawrence County.