 |
Meteorologists are not entirely sure what causes the somewhat rare weather event called a heat burst, but anyone who has experienced one can tell you they are quite bizarre. In most cases, the air temperature can increase 20°F or more in a matter of minutes, causing ferocious and damaging winds. What’s even more bizarre is that they almost always occur late at night or in the very early morning hours, which usually catches people by surprise. |
While the cause of a heat burst isn’t fully understood, it’s believed that a specific set of weather events must all be in place at the right moment. To begin with, the rain from a decaying thunderstorm must fall through a layer of very dry air. This in itself is uncommon, because in order to make thunderstorms, there needs to be moisture. Second, as the rain falls through the drier air, it evaporates and rapidly cools. This creates a pocket of very dense cool air that is much heavier than its surroundings. Because the air is heavier than it’s surroundings, it rapidly descends. As the air descends, it compresses, thus causing it to warm and at the same time gains downward momentum. This momentum causes it to overshoot its atmospheric equilibrium which further increases compression and warming. If the descending air has enough momentum, it will crash into the ground spreading out like a pancake. Those nearby will feel a substantial increase in temperature and a decrease in humidity until the atmosphere stabilizes, which can take up to an hour.
