FARGO — When the weather becomes humid, it is intuitive that there is an accompanying increase in thunderstorm activity. Storms do well in humid environments. However, trying to forecast the timing and location of storms during humid weather is often very hard. When the air is sticky with humidity, more water vapor is available to make raindrops, and the evaporation and condensation processes add tremendous amounts of energy to the atmosphere, making storms explosive. But storms also need something to get them started.
Often times during our most humid weather; the fronts, lows and other dynamics of the atmosphere are weak. This leads to forecasts of widely scattered storms, possibly severe, and some with very heavy rain. When people hear the forecast gloss over the qualifying, "widely scattered," they can get the impression that heavy rain is a certainty. In reality, these humid weather patterns often produce a few heavy storms and a lot of fine weather over the rest of the area.