Hurricane Michael weakens to a tropical storm while churning through Georgia

Hurricane Michael weakened to a tropical storm early Thursday morning while churning across central Georgia with maximum sustained winds of about 60 mph. Hours earlier, it made landfall as a Category 4 hurricane near Mexico Beach, Florida.

Storm flooding leveled off along the Gulf Coast as of 2 a.m. ET, the National Hurricane Center said. Tropical storm conditions were being felt in parts of central and southeastern Georgia.

The storm is expected to fan out over portions of eastern Georgia and the southernmost portion of South Carolina later Thursday morning.

Officials reported at least one storm-related fatality, a man in Greensboro, Florida, was killed when a tree fell on top of his home, a spokesperson for the Gadsden County sheriff said. An 11-year-old child was killed in Seminole County, Georgia, while the storm moved through the state Wednesday night, WTOC reported citing the Emergency Management Agency director Travis Brooks.

Hundreds of thousands of electricity customers were without power as of 6 p.m. Eastern time on Wednesday night. The US Energy Information Administration said about 388,000 customers in Florida, 46,000 customers in Georgia, and 45,000 customers in Alabama were in the dark as the storm moved inland.

The St. Marks River overflows into the city of St. Marks, Fla., Wednesday, Oct. 10, 2018.
AP Photo/Brendan Farrington

Gov. Kay Ivey of Alabama issued a state-wide state of emergency on Monday “in anticipation of wide-spread power outages, wind damage, and debris produced by high winds and heavy rain associated with Hurricane Michael.”

Gov. Nathan Deal of Georgia issued an emergency declaration for 92 counties in the southern part of that state. “The emergency declaration is effective for seven days and makes all state resources available to local governments and entities within the impacted area of the hurricane,” his office said.

Michael is likely to dump heavy rain over Florida, Alabama, Virginia, Georgia, and the Carolinas. Some of those areas are still working to recover from Hurricane Florence.

Tropical Storm Michael’s predicted path.
National Hurricane Center

A National Weather Service map shows when winds are likely to arrive in various states:

Hurricane Michael wind probabilities
National Weather Service

Forecasters said storm-force winds are possible in areas of southeast Virginia, northeast North Carolina and the Delmarva Peninsula when Michael moves off the mid-Atlantic coast late Thursday or early Friday.

The storm had picked up steam as it sped across the Gulf of Mexico toward the Florida Panhandle. When its eye hit Florida’s Gulf Coast on Wednesday afternoon, the storm had sustained winds of 155 mph, according to the National Hurricane Center, putting it just shy of a Category 5 hurricane.

Michael’s minimum central pressure — a key measure of hurricane strength — was measured at 919 millibars when it made landfall. That makes Michael the third-strongest hurricane to ever hit the US and the strongest in nearly 50 years.

Central pressure is the measure of how much the atmosphere in the middle of a storm weighs. Lower central pressure indicates a stronger storm. Michael’s measurement indicates it’s more intense than Hurricane Andrew, which hit Florida in 1992 with a pressure of 922 millibars, and Hurricane Katrina, which devastated New Orleans in 2005 when it hit with a pressure of 920 millibars.

Normal air pressure is about 1,010 millibars; when central pressure is significantly lower than that, things become more turbulent, with more air movement and wind kicking up.

Though wind speed is the basis for hurricane categories, central pressure is actually a better measure of damage that a hurricane will cause, a study published last year in the journal Nature Communications found.

Samantha Lee/Business Insider

Michael was a monster storm by wind speed around the time it made landfall. It had sustained winds of 155 mph, meaning it wasn’t from a Category 5 storm — a Category 4 hurricane has sustained winds of up to 156 mph, and Category 5 is 157 mph and above.

There has been only one storm with higher sustained wind speeds this far north in the Gulf of Mexico: Hurricane Camille in 1969.

As the Tallahassee office of the National Weather Service said on Twitter earlier Wednesday: “If you’re not sheltered in place now, you need to be!”