The tropical weather season revved up Thursday as the Atlantic's first hurricane formed and quickly strengthened, and as Tropical Storm Erin's remnants soaked rain-weary Texas, snarling rush-hour traffic and killing at least two people.

Even as they fetched dozens of stranded drivers, authorities in Houston and San Antonio looked over their shoulders at Hurricane Dean, a Category 2 storm building in the Atlantic as it neared islands in the eastern Caribbean. Hurricane warnings were issued for some islands, and a tropical storm warning was issued for the U.S. Virgin Islands and Puerto Rico.

The thunderstorms from Erin brought 7 inches of rain to parts of San Antonio and Houston, where one person died and another was injured when the waterlogged roof of a storage unit outside a grocery store collapsed, Fire Chief Omero Longoria said. The National Hurricane Center said 10 inches of rain was possible in some areas.

In San Antonio, a man was swept away after apparently getting out of his vehicle in floodwater, a police spokeswoman said. Three people died in a head-on collision on a rainy highway in Comal County, but Department of Public Safety Trooper Rick Alvarez said the cause of the crash was still under investigation.

The flooding "has been a good training session, if you will," as officials track Dean's progress, said Harris County Judge Ed Emmett, the top elected official in the county that surrounds Houston.

More rain was moving in Thursday from the Gulf - 3 to 6 inches was forecast for Thursday night - which authorities found particularly worrisome because the ground was saturated.

"It's like a wet sponge," Emmett said.

Summer storms have poured record rainfall across Texas and parts of Oklahoma and Kansas, with floods killing at least 18 people since mid-June. One July storm dropped 17 inches of rain in 24 hours and brought Texas out of a more than decade-long drought.

The dangers of a slow-moving storm system are well known in Houston, where Tropical Storm Allison stalled for several days in 2001, soaking the flat, low-lying city. After passing Houston, it returned, dumping about 20 inches of rain in eight hours. About two dozen people died, most of the city was without power and entire neighborhoods were destroyed.

Still, state and local officials said Erin was a relatively calm rehearsal for the hurricane season.

"It was a good dry run. I hope it stays dry," Corpus Christi Mayor Henry Garrett said after Erin had moved ashore as a tropical depression and largely spared the Gulf Coast city.

In the Atlantic, Dean's top sustained winds at 5 p.m. EDT were 100 mph, up from 75 mph earlier in the day. It was a Category 2 storm and centered about 210 miles east-northeast of Barbados. It was moving west at around 23 mph, and its center should approach the Lesser Antilles on Friday.

"It's so far out, but it's not too early to start preparing," said Katherine Cesinger, a spokeswoman for Texas Gov. Rick Perry. "We have more notice than with Erin. We're glad for that especially since (Dean) is projected to bring some strength."

Houston-based Transocean Inc., which operates the largest deepwater drilling rig fleet in U.S. waters in the Gulf of Mexico, said Thursday it had evacuated 11 nonessential workers late Wednesday as a precaution. About 125 people remain on board the moored, semisubmersible rig about 160 miles southeast of New Orleans.

Shell Oil Co. evacuated 188 people this week from offshore facilities in Erin's path and said Thursday it was already monitoring Dean.

The Caribbean islands of Dominica and St. Lucia issued hurricane warnings as Dean approached. Hurricane watches were issued for Martinique and Guadeloupe and its dependencies. About 2 to 5 inches of rain was expected, with mountainous areas getting up to 7 inches.

Tropical storm warnings were issued for Anguilla, Antigua; Barbados; Barbuda; Grenada and its dependencies; Monserrat; Nevis; Saba; St. Eustatius; St. Kitts; St. Vincent and the Grenadines; and St. Maarten. A tropical storm watch was issued for part of the southern coast of the Dominican Republic. A warning means storm conditions are expected within 24 hours, a watch means 36 hours.

Hurricane specialists expect this year's Atlantic hurricane season - June 1 to Nov. 30 - to be busier than average, with as many as 16 tropical storms, nine of them strengthening into hurricanes. Ten tropical storms developed in the Atlantic last year, but only two made landfall in the United States.


Associated Press writers Elizabeth White in Corpus Christi and Monica Rhor in Houston contributed to this report.