Climate Matters: Climate change brings heavier flooding but also more drought

Missouri has been under a near-constant drought alert for years costing the state hundreds of millions from losses in agriculture and livestock. But in a sharp turnaround, recent weeks have brought heavy rainfall and extensive flooding. This seesaw between extremes is a symptom that climatologists have been expecting from a shifting and warming climate.

Drought is popularly associated with climate change as a global increase in temperatures is expected to drive longer stretches of dry and hot weather. In between though, the heaviest rain events are dumping more rain in shorter periods of time. While the wettest days are getting wetter, the stretches of drought in between are also getting longer. This cycle of extremes can be especially vicious as long droughts can increase the impacts of flash floods.

When a region suffers under drought for an extended time the ground becomes more compacted and less absorbent. This can increase runoff during heavy rain events as the soil will initially repel water before it can percolate below the surface.

The current drought alert across Missouri has been running since May 2023 (following another stretch of drought from July 2022 to March 2023). This all changed in the past few weeks as central Missouri began experiencing record amounts of rainfall in a typically dry time of year. Columbia has already seen its wettest July on record and is still expecting more rain in the coming weeks.