Students from the Summer Cohesion Program at Hendy Avenue Elementary School were featured in this week’s Weather Wisdom. The question from the third group was, “How can tornadoes form at night when it is colder at night?”
According to the National Severe Storms Laboratory, although they can happen at any time of the day or night, most tornadoes occur between 4–9 p.m. You need instability, wind shear, moisture and lift to see severe weather development. For our area, we see these ingredients come into line more during peak heating hours (late afternoon to evening hours) as sunshine helps increase instability. Sometimes, we don’t always lose that instability once the sun goes down.
So, tornadoes can form at night. This can become dangerous, though. One obvious reason is it’s dark and hard to see if a tornado is coming. This means less time to prepare. Another obvious reason is people may be asleep and not hear the warning. In some cases, for people who are at home rather than their workplace, their homes may not be a structurally sound as where they work.