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Catastrophic flooding in Houston from Hurricane Harvey: what we know

“This event is unprecedented and all impacts are unknown and beyond anything experienced.”

Hurricane Harvey Slams Into Texas Gulf Coast
A guage shows the depth of water a an underpass on Interstate 10 which has been inundated with flooding from Hurricane Harvey on August 27, 2017 in Houston, Texas.
Photo by Scott Olson/Getty Images
Brian Resnick is Vox’s science and health editor, and is the co-creator of Unexplainable, Vox's podcast about unanswered questions in science. Previously, Brian was a reporter at Vox and at National Journal.

Catastrophic and life-threatening floods are currently drenching Houston, Texas, America’s fourth-largest metro area. More than 3 feet of rain have fallen in some areas. Feet more are expected. Roads are impassable. Thousands have been rescued from flooding homes, and search efforts are still underway. A total of 12,000 thousand National Guard members have been called into service, and civilians — from in and outside of Texas — have volunteered their boats for search and rescue. More than 30,000 people are going to need temporary shelter, FEMA reported Monday, and estimated that 450,000 people are likely to seek federal disaster aid. At least eight people have died in the storm, authorities report.

And it’s not over yet.

“This event is unprecedented and all impacts are unknown and beyond anything experienced,” the National Weather Center — a government agency known for its sober-minded messaging and avoidance of hyperbole — stated Sunday.

The situation is bad, and it could get worse. The weather service is calling the situation “catastrophic and life-threatening.”

Harvey landed in coastal Texas as a Category 4 hurricane Friday night, and within a day, its winds degraded to tropical storm strength. But now this is a new emergency altogether. Harvey has stalled (as forecast) over the Texas coast, and the flooding may continue for days. On Sunday, as the situation grew dire, the Weather Service advised people to “get on the roof” if the top floor of their home became dangerous.

As of Monday morning, parts of Houston and its surrounding areas had seen 30-to-40 inches of rain total. And so much more is to come. “Harvey is expected to produce additional rainfall accumulations of 15 to 25 inches through Friday [yes, Friday, as in September 1] over the middle and upper Texas coast, including the Houston/Galveston metropolitan area,” the National Hurricane Center reports in its latest forecast. “Isolated storm totals may reach 50 inches in this region.”

Fifty inches of rain is more than many of these cities in coastal Texas see in a year. It could break records for the amount of rain from a single storm. “The breadth and intensity of this rainfall are beyond anything experienced before,” the weather service stated Sunday afternoon.

Mandatory and voluntary evacuation orders were issued Sunday night and Monday for parts of Houston. However, the city was not evacuated prior to the storm hitting.

At a Sunday press conference, according to the Associated Press, Houston Mayor Sylvester Turner defended the position. “If you think the situation right now is bad and you give an order to evacuate, you are creating a nightmare,” Turner said. (As the Washington Post reminds us, Houston issued an evacuation order for 2.5 million people in 2005 for Hurricane Rita. It was chaotic: 100 people died while evacuating. People fleeing while roads quickly flooded could have been a catastrophic disaster in its own right.)

The scenes from Houston are dramatic and scary. Here, a Houston TV weatherman reports on the frightening flooding in his office.

“To get that much rain, over a wide area, and have the coastal areas elevated with storm surge — the waters are going to struggle to drain,” Hal Needham, a coastal flooding expert, said on Friday. And that’s when the forecast was for 35 inches at most. “Some areas are going to flood that haven’t before in recent memory,” he said.

The most recent shot of the flooding on Buffalo Bayou #houston #harvey #hurricane #weather

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Hurricanes are usually steered by upper-level winds in the atmosphere, Needham explains. But here, those winds have dissipated, leaving Harvey to wobble around for a few days. Needham stresses that from here on out, Harvey’s exact center location and wind category don’t matter. This is a wide-reaching disaster.

This storm has already left hundreds of thousands without power along the Texas coast. And there are reports of significant damage to buildings in Rockport, Texas, near where the storm made landfall Friday night. At a press conference Saturday afternoon, Texas Gov. Greg Abbott said it may be “several days before outages can be addressed,” due to continued high winds.

As with any hurricane or tropical storm, one of the greatest, most life-threatening risks comes from flooding. Even 6 inches of fast-moving water can sweep a person off their feet.

August 27, 2017: Tropical Storm Harvey creates epic flooding throughout Houston and Southeast Texas.
Robert Gauthier/Los Angeles Times via Getty Images

“When we look back on this, in historical context,” Needham said in an interview, “I think it will really be the flood that’s the main story.” For context, of the 34 direct deaths from Hurricane Matthew, which pummeled the East Coast from Florida to North Carolina in 2016, more than half were drownings from flooding.

Harvey is the first hurricane to land as Category 4 in Texas since Carla in 1961. The last hurricane to land at Category 3 in the US was Hurricane Wilma in 2005, and that caused $20.6 billion of damage in its path through Florida.

It’s scary any time such a strong storm hits a densely populated area. As meteorologist Eric Holthaus pointed out on Twitter, coastal Texas has grown tremendously over the past 15 years and is home to much of the country’s oil infrastructure. In preparation, Gulf oil refineries and platforms have shut down, and the price of oil has crept upward, anticipating a possible lower supply.

President Donald Trump declared Harvey a federal disaster Friday night before the storm hit, which activates federal money for emergency services and eventual cleanup.

Again, it’s important to reiterate: This storm isn’t over, and the Texas coast is likely to be feeling its effects for a long time.

How to follow Hurricane Harvey

  • Follow the Houston-area office of the National Weather Service on Twitter.
  • The National Hurricane Center has a page updating every few hours with the latest watches and warnings for Harvey. Check it out.
  • Follow the Capital Weather Gang’s Twitter account. These folks tend to live-tweet storm updates.
  • Here’s a Twitter list of weather experts via meteorologist Eric Holthaus. These experts will give you up-to-the second forecasts and warnings.

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