BLOG POST: All thunderstorms wear CAPE

Photo Credit: Brian Hill - Surgoinsville

Every so often, we have to upgrade our software that shows weather graphics. (It's called WSI TruVu MAX.) With the upgrade that we ran today, we received a new 'toy,' so to speak. We've always used this product 'behind the scenes,' but have never really been able to show it to you...UNTIL NOW!

We're talking about CAPE, which stands for Convective Available Potential Energy. This basically measures how strong rising air will be, which is important for thunderstorm forecasting. In fact, the mathematical equation is CAPE = √(2*updraft speed).

A warm, moist environment at the ground and cool, dry environment thousands of feet up is what we refer to as instability. In an unstable atmosphere, the air will rise more rapidly and the CAPE value would in turn be higher.

The higher the CAPE value is, the more thunderstorm potential exists. Keep in mind that it's just potential. There are other factors that go into forecasting storms. We'll get to that in a second.

The higher the potential, though, the more dangerous thunderstorms can get. The more rising air, the more water droplets are being collected. So, that leads to heavier rain and gustier downdraft winds. As the air is rising into cold air thousands of feet up, the lightning and large hail potential increases too.

As I mentioned before, though, this just measures potential. You can put gas in the lawn mower, but until you pull the trigger - it's not going to start.

For example, tomorrow - there's plenty of CAPE. Why? Because it's going to be hot and humid at the ground. BUT, a cold front is west of here and is helping produce more showers and storms in Ohio and Indiana.

By Friday, though, we have the gasoline in the mower AND we're pulling the trigger. The air will be hot and humid, but there will also be a front there to kick more storms off.

We plan on using this on air fairly often to highlight storm potential, but before we do that - we figured that explaining what this is would be helpful to you. Hopefully you think this is really cool, just as we do!

We think it will benefit you in the long run, and will also give something fresh to the everyday weather forecast!