New Weather Model Can Forecast Small But Long-Lasting Floods
By LIDA TUNESI
When it comes to flooding, almost all weather models are designed to predict the big and fast ones. But smaller, long-duration floods can wreak havoc too.
In a new study in Climate and Atmospheric Science, researchers from The City College of New York asked what causes these long-duration floods—defined as more than three weeks in duration. They developed a weather model to forecast these small, long-lasting floods before they hit. The authors include Professor Naresh Devineni and Nasser Najibi, a Ph.D. graduate.
“There’s a lot of industrial impact with these floods,” Devineni said. “Reservoirs get full but opening the dams creates downstream floods.” In 2011, Devineni said, Thailand experienced many days of flooding and eventually opened dams to prevent them from breaking. Manufacturing companies in the area were submerged and this created an international ripple effect. U.S. car manufacturers as well as hard drive prices were affected.
When storm tracks get blocked in the atmosphere by a cell of high and low-pressure regions, they release their rainfall, Devineni explained. When these tracks are trapped repeatedly, it can rain for many days. First the water will saturate the soil and fill the rivers, then inundate the land.
By using satellite data, the new model will be able to predict such long-duration floods between one week and 15 days ahead of time. It will also help local governments decide which reservoirs to focus on and how to operate their dams.
This new model is based on 50 years of data in the Missouri River Basin. The scientists are now fine-tuning it, and hope to expand their methods to create models for the rest of the U.S.