(Bloomberg) -- Subtropical Storm Alberto had a burst of strength as it closes on Florida’s Panhandle, where it should come ashore early Monday, and is spreading heavy rains across the U.S. South, potentially causing more than $1 billion in economic losses.
Alberto’s top winds jumped to 65 miles (105 kilometers) per hour, which will probably be as strong as it gets, wrote Richard Pasch, a meteorologist at the National Hurricane Center in Miami. Alberto is expected to steadily weaken after landfall and become a tropical depression Monday night or Tuesday.
“Little change in strength is anticipated before landfall,” Pasch said.
Heavy rain has already fallen in southern states, and flood and flash-flood watches span the region, reaching as far north as North Carolina and Tennessee, the National Weather Service said. Parts of Florida, Georgia and Alabama could get from 4 to 8 inches (10 to 20 centimeters) with some areas getting as much as a foot of rain. Governors in Florida, Mississippi and Alabama on Saturday declared states of emergency.
“The main concern from Alberto is flooding; not so much along the immediate coast, but inland, from the heavy rains that are coming on top of over a week of rain across the southeast,” said Chuck Watson, a disaster modeler at Enki Research in Savannah, Georgia. “A secondary concern is that even relatively minimal tropical storm winds can topple trees due to saturated soils and water-heavy limbs.”
Last week, another pulse of tropical moisture that didn’t rise to the level of a storm soaked the South.
Alberto could cause $400 million to $500 million across the region, including damage to cars crushed by toppled trees, wrecked roofs and flooding, Watson said in an interview. On top of that, there could be as much as $600 million in lost holiday spending as Alberto puts a damper on plans during the Memorial Day three-day weekend.
Alberto could come ashore early Monday, said Dan Pydynowski, a meteorologist with AccuWeather Inc. in State College, Pennsylvania. Its moisture could eventually push all the way to Canada.
West of Tampa
“We will be dealing with the rainfall and the moisture for most of the week,” Pydynowski said. “But the winds will die down pretty quickly.”
The storm was about 95 miles south-southwest of Apalachicola, Florida, moving northwest at 9 mph, the hurricane center said in an 11 p.m. New York time advisory.
On Friday, Exxon Mobil Corp. pulled non-essential personnel from its Lena oil production platform and Royal Dutch Shell Plc shut in its Ram Powell hub, but most other energy companies are leaving offshore crews in place while they watch 2018’s first Atlantic storm.
Chevron Corp. also shut oil production and evacuated personnel from its Blind Faith and Petronius platforms Saturday.
Alberto formed several days ahead of the official start of the six-month Atlantic hurricane season on June 1. In the end, it might not be wind and disruption to energy production that the storm is best known for.
Storms in the Gulf are closely watched because 5 percent of U.S. natural gas and 17 percent of crude-oil production comes out of the region, according to the Energy Information Administration. Onshore areas along the coast also account for about 45 percent of U.S. refining capacity and 51 percent of gas processing.
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