Moisture provides “hidden” heat for strong storms

Spring storms are expected for Thursday night, but the end of April has already experienced an early taste of summer due to the heat and humidity.

This late-April heat is particularly notable because of the high humidity levels. While Mid-MO has already recorded several sweltering days in the 90s as far back as March, the dew points forecast to reach the low 60s before storms move in late Thursday night are a significant factor. When dew points reach the 60s, the heat index will rise several degrees above air temperatures, making the heat feel more intense.

Although we are still weeks away from dew points in the 70s, at that point, people typically start to feel uncomfortable and describe a muggy sensation. By the mid-70s or higher, the air begins to feel tropical.

Dew points are also a valuable metric for predicting severe weather. Meteorology textbooks generally consider dew points of 55 degrees or higher as conducive to storm development. Higher dew points increase the likelihood of stronger storms.

Moisture is crucial for storm development; without it, clouds would not form. Even less obvious, water vapor in the air also stores energy for storms. When water vapor condenses into clouds or precipitation, it releases vast amounts of energy into the atmosphere.

Humid air is also more buoyant, another important concept in meteorology. Saturated air is actually lighter than dry air, which allows moisture to be carried up from the surface. This is because water molecules are lighter than oxygen and nitrogen.

Dew points in the 60s are common in the summer, but these numbers are significant during this time of year. The combination of heat and humidity has led the Storm Prediction Center to issue a 2/5 risk for severe storms in western Missouri overnight.