A firefighter directs traffic away from deep water at an intersection Thursday in San Antonio.

Houston ? 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.

In the Atlantic, Dean’s top sustained winds at 4 p.m. CDT 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 about 23 mph, and its center should approach the Lesser Antilles today.