'Atmospheric brick wall' leads Hurricane Florence to US East Coast

Probability of Hurricane Florence reaching tropical storm winds (magenta is the highest probability). (National Weather Service) Forecasters report that Hurricane Florence

is moving rapidly toward the southeastern United States due to a so-called "atmospheric brick wall." The brick wall is likely to play the villain again if a hurricane makes landfall; Brick expects the wall to weaken, meaning it won't help guide Florence toward the sea. Instead, Florence is expected to linger inland, where it could dump at least a foot (0.3 meters) of rain, said Michael Bell, associate professor of atmospheric sciences at Colorado State University. "There's a lot of uncertainty about the results of this study," Bell told Live Science. [Hurricane Season 2018: Duration and Expectations]

During a typical Atlantic hurricane season, most hurricanes are controlled by high-pressure systems around Bermuda, Bell said in an interview with Live Science: "Most come from Storms in Africa typically move from east to west, and then they curve around the high-pressure system to move north and hopefully into the Atlantic. "So, this high pressure is pushing Florence toward the east coast right now." ". As Florence approaches the coast, the weather forecast will become stronger. According to the U.S. National Hurricane Center today (September 11), Florence's wind speed is currently 130 miles (215 kilometers) per hour, and Hurricane Saffir-Simpson A Category 4 hurricane on the wind scale is "very good," he said. The combination of factors sometimes helps steer [hurricanes] away and sometimes steers them toward land, Bell said. "The steering flow that's driving (Florence) right now will stop or cease. ". Without a high-pressure system to guide it, Florence could linger and dump heavy rainfall, much like Hurricane Harvey did over Houston last year.

"Harvey is both northwest and northeast of "A large high-pressure system that caused it to stall and linger over the Texas area for almost a week," Bell said. Fortunately, it looks like - at least there are early indications - we won't see that for quite a while ( rainfall), but even a few days of rainfall from a hurricane can be very severe, and that's what we're worried about right now

However, hurricanes are notoriously unpredictable, Bell said. The National Hurricane Center has mapped another weather disturbance in the Caribbean, and it's unclear if and how this one will interact with Florence. Additionally, how much rainfall will fall inland will depend on the exact time and location of landfall.

Even the intensity of a hurricane can affect the direction it takes, he said, because "the atmosphere has different winds at different heights, so the winds at higher levels may be different than those at lower levels. wind. ” Bell said it wasn’t just a cork in the stream.

There are a lot of interactions between storms and the environment, and I think this is a difficult problem to solve, but an important one to study