Heat Lightning - @wxornotBG

Alright, I can’t help but to talk about this topic because of it’s popularity in our area and the fact that we are getting close to the time of year that it will come out of hiding. So, we’ve all heard the term “Heat Lightning” in our day-to-day conversations about the weather, and especially during the summer time. Basically, from what I understand, the term heat lightning comes from lightning that happens during warm, summer nights and is “caused” by the high amounts of heat in the atmosphere. Well, although that is completely incorrect, there is in fact an association with the heat that heat lightning is derived from.

In recent posts I’ve spoke about Air Mass Thunderstorms and Lightning, and this is a topic incorporating both. Basically, it is common to have complexes or single-cell varieties of thunderstorms ongoing at night during the summer months as it takes some time for convective properties of the atmosphere to settle down. Lightning that is generated from these storms is often seen from several miles away and the thunder that is generated cannot travel the same distance as acoustic properties of the atmosphere dilute sound through space. So what happens is you see a distant flash of lightning, and often times with stars visible overhead, and no thunder is heard or no rain is falling. All you have is the flash of lightning and the warm, moist air surrounding you. Thus, it’s “Heat Lightning”.

So what is going on exactly? Here’s a visual:

Flashes of lightning from distant thunderstorms may look something like this. – Courtesy of the NWS

Generally speaking, thunder from lightning can only be heard within about 10 miles. Furthermore, the curvature of the earth and topography blocks most of the line-of-sight to the thunderstorm causing the lightning as well. So if there are storms in the next town over, what you may see is a landscape similar to the animation above.

Heat lightning is not a specific type of lightning, it’s just combination of a typical warm, humid summer night and the amazing phenomena of lightning off in the distance. It’s that simple.

Next week I’ll discuss “Heat Lightning Bugs”. Just kidding.

Check back for more interesting topics in the coming days!