Hurricane Harvey Will Hit Houston

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On Friday evening, hours after making landfall in Texas, Hurricane Harvey intensified into a Category 4 storm. Officials have warned of catastrophic flooding throughout the state, and several cities and counties are under mandatory evacuation orders. Hurricane Harvey will hit Houston as it makes its way across the coast, and the city's residents and officials are planning accordingly.

Although Monday was supposed to be the first day of school in Houston, class has been canceled in light of the hurricane, CNN reports. Coldplay has canceled a concert that was supposed to take place Friday, and the Houston Dynamo soccer team scrapped a game scheduled for the weekend.

The National Hurricane Service had already warned of "catastrophic and life-threatening flooding," and Houston is at a particularly high risk of floods due to its topography. Harrison County has declared a state of disaster in Houston, and flash flood warnings are in place in both Houston and nearby Galveston.

"It's possible that some spots could get up to 30 inches of rain -- it won't be everywhere -- but it will be in spots and so those spots that get that much rain, clearly, they will have a very significant flood threat," KHOU 11 meteorologist David Paul said on Friday afternoon.

There are several reasons why Harvey is expected to cause catastrophic flooding, both in Houston and elsewhere in the state. In addition to the fact that it's a Category 4 storm, it will be accompanied by severe storm surge, which is when a hurricane "pushes" the water between itself and land onto the shores, causing floods. On top of that, the hurricane is predicted to hover over Texas for several days before dissipating; it will be raining heavily during that time, and that rain will exacerbate the existing flooding.

Many cities and counties along the Texas coast are currently under mandatory evacuation orders. However, no such orders have been issued in Houston yet. In a Friday tweet, Houston Mayor Sylvester Turner asked his city's residents to "please think twice before trying to leave Houston en masse."

In 2001, Houston was devastated by flooding brought on by Tropical Storm Allison. Although wind speeds topped out at 60 miles per hour, the rainfall caused catastrophic flooding, claiming 22 lives in Harris County and causing roughly $5 billion in damages. TheWashington Post reported that around half of those who died were in automobiles at the time, and warned those in Harvey's path not to drive on roads, bridges or freeways if they appear to be completely covered by water.