How the drought actually helps make it hotter.

Well, it doesn’t take a meteorologist to tell you this summer has been really hot and really dry so far. So far in Summer 2015 we are on pace for one of the top 5 hottest summers on record in Charlotte. Those records go back 137 years. 

Here are the top 10 hottest summers on record in Charlotte.

2015-07-15_9-48-07

Drought Monitor:

20150707_southeast_trd

 

Now we could get into the what came first argument here. Was it the heat or the drought? Either way the heat and drought are tied together and as things get drier the air gets hotter. It’s something we call a positive feedback mechanism. Here’s how that works.

If you have ever boiled water you know, it takes a long time to get the water to a boil on the stove. This is because water has a high specific heat. Which means it takes a lot of energy to warm up or cool down water. So when you are boiling the water on the stove, the pan heats up really fast but the water takes a long time. Especially when my daughter wants mac and cheese, but I digress.

So how does this relate to the drought?

Well, you see the way the sun heats us up is by first heating the ground which then heats the air. When there is lots of moisture in the ground2015-07-15_10-04-17 and in the surrounding vegetation a lot of the suns energy goes into evaporating the water instead of heating up the ground and air. So when we are in a drought like we are, the sun can heat up both the dry cracked ground fast and the air equally as fast. It’s just like heating up the pan and not the water when you are boiling water.

This warmer air due to the dry ground over time can actually help to strengthen the upper ridge of high pressure that is causing the heat wave to begin with. This is that positive feedback I was referring to. This is why when we get into a pattern like this in the summer time in the Carolinas it can be so hard to break out of it. The good news is usually by the end of the summer the pattern breaks on its own.