INDIANAPOLIS — A survey crew with the National Weather Service has found the signatures of two more tornadoes unleashed by last Sunday's outbreak, boosting Indiana's total for that day to 28 tornadoes — nearly twice the highest number the state had ever recorded in November.
Weather service meteorologist Mike Ryan said Saturday a survey crew confirmed Friday that two other tornadoes, both rated an EF-1, had touched down Nov. 17 in west-central Indiana, along with the 26 others already documented around the state.
One of the tornadoes the crew documented Friday had maximum winds of 110 mph and cut a 2-mile path through northern Montgomery County just east of New Richmond. Ryan said the same storm that produced that tornado also spawned a second one with top winds of about 100 mph that cut a 3-mile path across southeastern Tippecanoe County near the town of Stockwell.
The weather service's findings are still preliminary, and Ryan said signs of additional tornadoes could presumably still be found in the days ahead.
"That number might pop up a little higher, but this may end up being it," he said. "Everyone's going to take a breather this weekend, and then we'll re-evaluate Monday on whether any further surveys need to be done."
Indiana's Nov. 17 tornado outbreak was produced by unusually warm moist air from Louisiana to Michigan that was buffeted by an upper-level cold front, creating a clash between starkly contrasting air masses.
Ryan said Indiana's previous largest November tornado outbreak produced 15 twisters. Last week's outbreak was also Indiana's third-largest tornado outbreak on record.
Indiana's most active tornado day was June 2, 1990, when 33 tornadoes touched down, followed by 29 twisters on April 19, 2011, and then last Sunday's 28 tornadoes, which caused damage in Kokomo, Lebanon, Lafayette and other areas.
Among Indiana's top six worst tornado outbreaks, the Nov. 17 outbreak is only one to occur in autumn. The five other top outbreaks all occurred in April, May or June.