Heat lightning seems to be a very misunderstood term. Sometimes even the experts have a hard time explaining the phenomena. Often times sheet lightning and heat lighting are confused, so let’s get down to the nuts and bolts.
Heat lightning is the flash of lightening without an audible cue of thunder. Usually it is caused by a distant storm and is normally associated with summer storms. Some times heat lighting is a reflection from a very distant storm and sometimes the bolt can only be distinguished as a flash. It often takes on a reddish cast and be associated with very dark clouds.
Sheet lightning or cloud lightening is when lightning discharges inside a cloud and lights up the entire cloud. You still hear the thunder.
So why can’t you hear thunder with heat lightning? Of course there is more than one possibility. It could be that the storm is simply too far away for you to hear the thunder. Sound travels differently that light. The movement of sound through the atmosphere is dependent on the properties of the air, temperature and density. This means that the sound travels through the troposphere. The refraction results in spaces of volume which the thunder does not reach. If you live in a very mountainous area someone a mile down the road may hear thunder that you can not.
The sound of thunder can reflect off of the earth’s surface. This surface is not flat but has a curvature and it has many dimensions. It sometimes behaves like a wild bouncing ball and there seems to be no way to predict who may hear the crashing thunder.
The term “heat lightning” doesn’t have anything to do with the temperature of the bolt or sheet of lightning. It is most likely to be associated with air mass thunderstorms. This type of storm is usually a relatively week storm and doesn’t usually last a great length of time. It is slow moving and normally doesn’t produce severe weather. These tend to be the storms you see on warm summer afternoons.
Lightning is something that should not be ignored. In an average year more Americans are killed by lightening than by tornadoes. According to estimates lightning is striking somewhere on this earth about 100 times every second. It’s a powerful force to be reckoned with. Check out the Red Cross to find out how to protect your self from all sorts of weather. Separate myths from fact and keep yourself safe in the storm.
