INDIANAPOLIS (AP) – Emergency officials are planning to sound outdoor warning sirens across Indiana as part of an annual statewide tornado drill. 

The National Weather Service plans to set off two tests Thursday by weather radio and to local officials as part of Severe Weather Preparedness Week. The purpose of the tests is to allow communities to check their warning sirens and for people to conduct safety drills at schools, businesses and homes.

The tests are set for 10:15 a.m. and 7:35 p.m. The tests will be postponed if there is severe weather. 

The weather service says Indiana had 28 tornadoes last year, topping the annual average of 20. April 11 will mark the 50th anniversary of the Palm Sunday outbreak during which 10 tornadoes killed 137 people in Indiana.