With heat indices expected to rise between 100 and 110 over the next several days, the National Weather Service has issued an Excessive Heat Warning for the entire Miami Valley from 2 PM this evening through 8 PM Saturday.
The upcoming heat will be the result of an area of high pressure located to our south. High pressure can help generate extremely hot temperatures in two ways.
First, in the northern hemisphere, high pressure systems rotate clockwise. This means that, with the high located to our south, the Miami Valley will see predominantly southwest winds. This wind shift helps draw in warm, humid air from the Gulf of Mexico and results in hot temperatures.
Second, high pressure systems are characterized by sinking air. This prevents hot air from rising, keeping the temperature warmer at the surface. Additionally, sinking air inhibits cloud development resulting in more sunshine and fewer rain showers. This also contributes to consistently hot temperatures.
Extremely high heat indices, such as those we’ll see the next few days, can be very dangerous.
A high heat index indicates not only hot temperatures, but also high humidity, which means there’s a high concentration of water vapor in the air. When there is more water vapor in the air around us, it is harder for the sweat on our skin to evaporate. This prevents us from cooling as efficiently as we normally would and increases the chance of experiencing heat exhaustion or even heat stroke.
Click here for more information on how to stay safe during the hot weather: