Drought Continues in Alabama

Dr. Sagy Cohen predicts drought using hydrology map

Using the global hydrology model that he helped develop to study rivers and floods, Dr. Sagy Cohen says he was able to predict the drought before it happened

From the January 2017 Desktop NewsAccording to Dr. Sagy Cohen, an assistant professor in the Department of Geography, drought doesn’t end at the first sign of rain or even heavy downpour.

“When we got that downpour the first week of December, people thought the drought was over,” Cohen said. “But that’s not true.”

In fact, though the National Weather Service predicted a wetter-than-average December in the Southeast, there has not been enough rain to make up for the deficit of precipitation that began in June and lasted through late November.

“The damage has already been done,” Cohen said. “One of the big concerns that was raised at the start of the drought was the lack of hay for cattle. If people don’t grow enough hay, then they need to buy it, and because everyone is buying in the region, it becomes very expensive. Also, depending on what crop famers were growing, they may have already lost the entire season.”

According to the National Weather Service Forecast Office, Tuscaloosa usually receives 52.60 inches of rain each year, but by Dec. 31, 2016, the area was 15.09 inches below that average.

That means Lake Tuscaloosa, which covers roughly nine square miles, is more than 2 feet shallower than normal.

“Lake Tuscaloosa is very large, so in this area, we are not in danger of running out of water any time soon,” Cohen said. “However, two feet on a lake of that size is a lot of water.”

In part, Cohen says that the drought may have been triggered or enhanced by atmospheric processes associated with the strong El Nino event that occurred this summer, and he suggests that the current La Nina, though weak, will potentially slow drought recovery because La Nina events typically lead to dry winters in the Southeast.

Using the global hydrology model that he helped develop to study rivers and floods, Cohen says he was able to predict the drought before it happened, and using the same model, he suggests that southern Alabama will likely recuperate before northern Alabama, which may not recover from its deficit until the end of winter. Still, Cohen says that weather is unpredictable, and that even these models may not predict the future.

The good news is, the slow recovery is already underway. While 100 percent of the state was in some state of drought from Oct. 11 to Dec. 13, current data from the United States Drought Monitor suggests that only 77 percent of the state is still in partial to severe drought.

For up-to-date information on the drought, visit droughtmonitor.unl.edu and w2.weather.gov.