Climate Matters: Messaging for flooding in a warming climate
Flooding is already the most frequent, costliest, and deadliest weather disaster, and it will likely get worse as the climate warms.
Warmer air can hold more moisture, increasing the likelihood of heavier rainfall events in the future. Climate Central reports that rainfall intensity has risen by over 20% in the last 50 years in St. Louis.
Knowing exactly when and where flooding will strike is still tricky, even with today's science. Jon Carney, a meteorologist at the National Weather Service in Saint Louis, says their flood alerts are based on guidance from river forecasters. "So, we have what's known as flash flood guidance that's issued to us from river forecast centers, and that flash flood guidance tells us how much rain can fall in a certain period of time," Jon says.
This guidance is usually structured over one-hour, three-hour, and six-hour periods. "Let's say our one-hour flash flood guidance is two inches, when we start seeing that much rainfall come up here, to the flash flood guidance, that's what is supposed to put our creeks and streams at bank full," Jon explains, "So when it starts to go over that flash flood guidance, usually we start looking for about 120 to 150% over flash flood guidance. That's when we start issuing products."
Flood alerts can be easy to ignore, but they can save your life. "If we put out a watch or a warning, pay attention to it. If your phone goes off in the middle of the night, and it says flash flood warning, and you're in an area that is prone to flooding, it's time to take action," Jon says.
He also cautions against driving into flood waters. "'Well, I've driven through this low water crossing all my life a thousand times.'" Jon mimes, "Well, it's the 1,001st that gets you." The frequency of flood-related deaths on roads has given rise to the popular adage 'turn around, don't drown.'
It's always best to have a NOAA weather radio as a backup during severe weather and flooding, in case you lose cell service.
