National Geographic News
Sergio Alvarez shovels sea weed off a board walk as the lingering effects of Tropical Storm Alex are felt along the Texas coast, Thursday, July 1, 2010 in South Padre Island, Texas.  The Atlantic season's first hurricane largely spared Texas, which had prepared for a possible direct hit. While it brought rain, spawned two tornadoes and caused 1,000 people to evacuate low-lying areas there, state officials reported no injuries or major damage. (AP Photo/Eric Gay)

Sergio Alvarez shovels seaweed on South Padre Island, Texas, as Alex's effects linger Thursday.

Photograph by Eric Gay, Associated Press

Willie Drye

for National Geographic News

Published July 1, 2010

Eventually spawning tornadoes and killing at least three people, a strengthening Hurricane Alex came ashore Wednesday night in northern Mexico.

Hurricane Alex, however, did not push spilled oil from the Deepwater Horizon disaster beyond the coastlines along the Gulf of Mexico, as had been feared. (See "Hurricane Could Push Spilled Gulf Oil Into New Orleans.")

And, once over land, the hurricane rapidly weakened and was downgraded to tropical storm Alex.

Hurricane Alex made landfall around 9 p.m. CT at the village of Soto La Marina, about a hundred miles (160 kilometers) south of Brownsville, Texas. (See Gulf of Mexico map.)

Flash flooding had been reported where the storm came ashore, said William Wagner III, president of Early Alert, a private emergency management consulting firm in Palm City, Florida.

"We got reports that a lot of fishing villages were hit pretty hard," Wagner said.

(Pictures: "Hurricane Alex Pushes Oil on 'Cleaned' Beaches.")

Hurricane Alex Could Have Been Much Stronger

Hurricane Alex's hundred-mile-an-hour (160-kilometer-an-hour) winds made it a Category 2 hurricane at landfall.

But the storm could have easily become much stronger, based on Alex's barometric pressure readings, said Jim Campbell, a meteorologist at the National Weather Service office in Brownsville.

Barometric pressure—the force created by the weight of air—is an indicator of a storm's intensity, because the strong thunderstorms created by tropical storms decrease air pressure around the center of the storm. As the storm strengthens, the barometric pressure becomes lower, and winds accelerate.

Hurricane Katrina, for example, had a barometric pressure reading of 923 millibars when it made landfall in August 2005. Alex's barometric pressure at landfall was 947 millibars—the lowest for a June hurricane since 1957.

Also, radar showed that, just before landfall, Hurricane Alex was starting to gain momentum and intensify over very warm water, which is fuel for hurricanes, Campbell said. But making landfall caused the storm to become disorganized and weaken before its winds could become stronger.

"Just think what could have happened if it had had another hundred miles or so of water before it came ashore," Campbell said.

(See "Hurricane Season May Be 'Extremely Active.'")

Alex Unleashes Tornadoes

Alex spurred several tornadoes in Brownsville, including one that blew a tractor-trailer truck into a mobile home.

Hurricanes making landfall often spawn tornadoes because of the storms' interaction with the ground, according to Brian LaMarre, a meteorologist at the National Weather Service office in Slidell, Louisiana.

A hurricane usually harbors cells of intense thunderstorms. Contact with land can cause the thunderstorms rotate more intensely, and that can produce tornadoes, he said.

LaMarre said Hurricane Alex did not push spilled oil beyond beaches because the storm made landfall about 600 miles (1,000 kilometers) west of the Gulf spill site. (Related: "Hurricane Alex 'So Darn Large,' But Oil-Storm Fears Unfounded?")

But, he added, high waves and winds produced by Alex have temporarily halted work being done by BP to burn the oil and skim it from the Gulf's surface.



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