Why Did Rainfall Totals Not Live Up To Projections?
Barry is a tropical depression in Arkansas today after dumping several inches of rain, knocking out power and producing some flooding along the coast. But Barry didn’t live up to projections of major flooding of 15 to 20 inches of rain. State Climatologist Barry Keim says you can thank wind shear that the models didn’t take into account.
“And the shear did not allow the storm to develop the classic symmetrical cloud pattern you see in a normal hurricane, in this case, all of the convection and rain was taking place south of the storm,” said Keim.
Keim says forecasters use multiple models in order to come up with a rainfall prediction, but in this case, they were not accurate.
“As such the models really produced loose guidance on what’s possible, but they don’t produce exact predictions, they just really forecast with certain probabilities and occasionally you roll snake eyes,” said Keim.
But Keim says you have to forgive forecasters for using the information available and predicting a Category One hurricane would make landfall in southwest Louisiana four days before it actually happened.
“That I thought was really mind-blowing and represents a real breakthrough in forecasting,” said Keim. “I don’t ever remember us being that accurate with something that small and seemingly insignificant before this event.”