The "atmospheric brick wall" brought Hurricane Florence to the east coast of the United States.

The probability of hurricane Florence reaching tropical storm wind (magenta is the highest probability). Forecasters report that Hurricane Florence is moving rapidly in the southeastern United States because of the so-called "atmospheric brick wall". If the hurricane lands, this brick wall is likely to play the villain again; The brick wall is expected to weaken, which means it will not help to lead Florence to the sea. Michael Bell, an associate professor of atmospheric science at Colorado State University, said that instead, Florence is expected to move inland, where there may be at least one foot (0.3 meter) of rainfall.

However, Florence is not expected to land until Thursday (September 13). Bell told Life Science magazine: "There are still many uncertainties about the results of this study." . [Hurricane Season 20 18: Duration and Expectation]

In the typical Atlantic hurricane season, most hurricanes are controlled by the high-pressure system around Bermuda. In an interview with Life Science magazine, Bell said: "Most storms from Africa usually move from east to west, then bypass the high-pressure system and move north, and hopefully enter the Atlantic Ocean." Therefore, this high pressure is currently pushing Florence to the east coast. "。 As Florence approaches the coast, the weather forecast will become stronger. According to the data of the National Hurricane Center (September 1 1), the current wind speed in Florence is 130 miles (2 15 kilometers), which is a category 4 hurricane of safire-Simpson scale. He said that the combination of these factors sometimes helps to transfer (hurricanes). . Without the guidance of the high-pressure system, Florence may stay and have a lot of rain, as Hurricane Harvey did in Houston last year.

"Harvey had a large high-pressure system in the northwest and northeast, which caused it to stagnate and stayed in Texas for nearly a week," Bell said. Fortunately, it seems-at least there are early signs-that we won't see it for such a long time, but even a few days of hurricanes can bring very serious rainfall, which is what we are worried about now.

However, as we all know, hurricanes are unpredictable. Bell said, first of all, the National Hurricane Center has mapped another meteorological disturbance in the Caribbean, and it is not clear whether and how this disturbance interacts with Florence. In addition, the rainfall in the interior of Florence will depend on the exact time and place of landing, he said.

Even the intensity of a hurricane will affect its direction, because "the atmosphere has different winds at different heights, so the winds at the upper level may be different from those at the lower level." Bell says it's not just a cork in a stream. There are many interactions between storms and the environment. I think this is a difficult problem to solve, but it is also an important problem to be studied.