By CHRISTINA CARON
Catastrophic flooding is expected in Texas as Hurricane Harvey slowly moves across the state, stalling over the southeast and producing a “multiday rainfall disaster” over the next five to six days, according to the National Hurricane Center.
Forecasters are expecting 15 to 30 inches of rain and isolated amounts as high as 40 inches, said Michael Brennan, acting chief of the center’s Hurricane Specialist Unit.
The greater Houston area has already gotten more than 5 inches of rain, Brennan said. Areas in far South Texas, the Texas Hill Country and southwest and central Louisiana could see 5 to 15 inches of rain.
A storm surge warning is in effect from Port Aransas to High Island, Texas, the National Hurricane Center said, which means a dangerous amount of rising water is expected to move inland.
Jamie Rhome, who runs the Storm Surge Unit at the National Hurricane Center, said the winds were still pushing toward the coastline, which is keeping the saltwater elevated, but “inland flooding is the primary threat from here on out.”
Tornadoes are also possible Saturday near the middle and upper Texas coast into far southwest Louisiana.
Harvey came ashore Friday night northeast of Corpus Christi, Texas, making landfall as a Category 4 storm with 130-mph winds. It made landfall again later on the northeastern shore of Copano Bay.
The storm was downgraded to Category 1 on Saturday morning, and maximum sustained winds have decreased to about 75 mph near the center of the hurricane. Harvey is likely to become a tropical storm Saturday afternoon, the National Hurricane Center said.
Coastal areas from Baffin Bay to High Island are at risk for tropical storm conditions, while hurricane warnings continue for inland areas.
During tropical cyclones, “wind tends to get all the attention,” but “water is what kills most people,” Brennan said.
As the storm weakens, the rainfall threat will not change, Brennan said, and it can lead to flash flooding that occurs with little warning, as well as river flooding.
“Rainfall doesn’t care how strong the storm is,” he added.
A recent study by the American Meteorological Society showed that storm surges and rainfall were responsible for about 76 percent of the fatalities from Atlantic tropical cyclones in the United States from 1963-2012.
The extent of surge-related flooding depends on how high the tide is when the surge occurs. If peak surge happens during high tide, areas from Port Aransas to Sargent could see as much as 7 feet of water above ground.