Dear Tom,
Why is it that most tornado warnings seem to come in late afternoon or early evening? Is that a coincidence or is there some science to it?
Ed Galvin
Dear Ed,
There absolutely is some science to it. The vast majority of tornadoes occur in the late afternoon or evening, when the atmosphere is most unstable after a full day of solar heating. The peak time of occurrence is between 6-7 pm and about half of all twisters occur in the 4-9 pm time frame. That being said, twisters can occur anytime of the day or night. Tornadoes are least likely from 6 -7 am with only 6 percent occurring between 7 am and noon. However, morning tornadoes do occur. An F-2 twister struck Arlington Heights a little after 6 a.m. on June 9, 1966, killing one and injuring 23 as thunderstorms packing wind gusts of up to 80 mph swept the Chicago area.
