An unprecedented problem could worsen the damage inflicted on New Orleans by Tropical Storm Barry, which is likely to become a hurricane as it hits Louisiana.
The outer bands of the storm began to hit Louisiana on Friday, prompting evacuations, and bringing flooding, rain, and what the National Hurricane Center warned is “life-threatening storm surge.”
But the conditions brought by the storm could end up being worse for the city than what would typically be expected in these conditions because the Mississippi River is higher than normal: it currently has a water level of 16 feet.
CNN quoted Jeffrey Graschel, a hydrologist with the National Weather Service’s Lower Mississippi River Forecast Center, as saying that the issue is unprecedented.
“This is the first time we’ve had a tropical system with water levels on the river this high,” he said.
The storm is expected to test the city’s levees, potentially more than the deadly 2005 Hurricane Katrina did. That hurricane killed more than 1,800 people after levees failed.
The levees are only 20 feet high in some places — and the flooding from Barry could potentially exceed that level, the National Weather Centre warned.
The NWS warned that “flooding is expected to be the most significant threat” to the city.
Louisiana Gov. John Bel Edward said that he does not expect the river to rise over the levees, but that changes in the storm’s strength or path could change that prediction, The Associated Press reported.
LaToya Cantrell, the mayor of New Orleans, warned that the city’s water pumping system could not drain the amount of water that is expected to fall on the city, the AP reported: “We cannot pump our way out of the water levels … that are expected to hit the city of New Orleans.”
Barry is expected to make landfall on Saturday morning, and could do so as a hurricane.
“Some strengthening is expected during the next day or so, and Barry could become a hurricane tonight or early Saturday when the center is near the Louisiana coast,” the NWS said on Friday morning.
The storm is expected to bring “flash flooding and river flooding,” according the NWS, which has issued a hurricane warning, which means hurricane conditions are expected in the area, for Intercoastal City to Grand Isle.
The storm is slow moving, which the NWS said meant more rain and a larger flood threat than a faster hurricane that spends less time in one place.
The service predicted on Friday morning that the storm will bring between 10 and 20 inches of rain over southeast Louisiana and southwest Mississippi, with a maximum of 25 inches.
The NWS said that hurricane conditions were likely to begin on Friday night or Saturday morning along parts of the coast.
Evacuation orders have been issued for thousands of people, but not in New Orleans, where the storm is not expected to directly hit.
Storm surge and the tide will cause “normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline,” the NWS said.
As of 4 a.m. CDT on Friday, the storm was around 95 miles (155 kilometers) southwest of the mouth of the Mississippi River with maximum sustained winds of 50 miles per hour (85 kilometers per hour).
US President Donald Trump declared a state of emergency for the state on Thursday night, allowing federal agencies to coordinate disaster relief efforts.
