In addition to a weather radio and cell phone apps, you can sign up for StormWarn which will alert you for tornadoes and winds strong than 80 mph (only) and then only if you are in the path of the storm. 

Tragically, Two Fatalities Caused By the Tornado  East of Lansing Power is out in much of Lower Michigan at this time. More than 340,000 homes = ~800,000 people.  A strong or even violent (EF-4 or stronger) struck the Williamson - Webberville areas. There are reports of cars in trees and buildings that have collapsed. It touched down about 9:29-9:31p. The image below shows lofted debris (top image) along I-96.  At 9:36pm, the tornado, based on radar, reached its maximum strength.  There is a technique for measuring tornado intensity via radar. Its results are below.  The path, derived by radar, is below. It more or less paralleled the freeway for a few miles. The blue indicates a possible strong tornado. There is much more on the tornado, here . Tornadoes also occurred in the north suburbs of Grand Rapids and in the west and south suburbs of Detroit. There was significant damage with the former storm.  Addition: Downtown Detroit is at upper right. The red a...

This was the monster tornado near Hayti, Missouri (Bootheel) along the 200+ mile long rotation track (we don't know yet whether it was one, or multiple, tornadoes) from Arkansas to central Kentucky. If the Governor of Kentucky and others are correct, it caused at least 75 fatalities. Below is a map of the approximate track; it is the more northern of the two parallel rotation tracks.  The video was taken around 9pm -- about four hours after sunset and after some had retired for the night. Nighttime tornadoes, depending on the research results, are twice to three times as deadly as tornadoes during the day. I knew this one would be especially bad because no one is thinking of tornadoes two weeks before Christmas. So, I wonder how many people received and acted upon the excellent forecasts. I am also having a difficult time recalling a tornado outbreak when so many violent tornadoes occurred at night. While there have been individual F-5 tornadoes (Udall, Greensburg, etc.) that have ...