Climate Matters: Rainfall is getting heavier and more extreme
Flooded rivers are finally receding after extreme rainfall drenched states from east Texas to the Ohio Valley. Many areas received over a foot of rain in just a few days, leaving rivers in major flood stages several days after the rain had stopped pouring.
Rain started falling on April 2nd as a front settled across the central part of the country, where it would linger through April 7th, swamping cities and filling rivers to the brim. Flooding aside, this multi-day stretch of severe storms produced at least 127 confirmed tornadoes and over 850 reports of wind, hail, and other storm damage.
The extensive flooding was just as disastrous, though not as extreme as some floods of the past. Steve Runnels, the warning coordination meteorologist at the National Weather Service in Springfield, Missouri, says that while this was a very heavy rainfall event, we've seen others that were much more impactful. "For example, going back to November, just this last fall, we had almost the same amount of rain, but in just a couple of our basins, like the big Piney River," Steve says the same amount of water in a smaller area or basin can have much worse impacts.
Rainfall intensity is rising as the climate changes and temperatures warm, with a 25% increase in rainfall rates in St. Louis over the last half century. More extreme rainfall from climate change means more danger from what is already the costliest and deadliest weather disaster.
The National Weather Service accounts for that in their forecasts. "Each one of those events roughly has a 2% chance of occurring in any given year. About a 50-year flood in some other ways in which to consider this." Steve says, "From an atmospheric setup standpoint, the warmer the air is, the more moisture it can hold and the heavier the rainfall can be." Those are the things that the National Weather Service is looking for ahead of any given storm system.
Steve also draws attention to flooding-related deaths on roadways. "Indeed, we did see two fatalities in the West Plains area where people did drive into these flooded water crossings and cause their cars to be displaced off the road. So, you know, yes, it's historic in terms of the rainfall and the river gauges, but when it comes down to that water getting into people's homes or, unfortunately, people trying to drive across the water go water crossing, that's where the main impact becomes."
