(CNN) -- Tropical Depression Alex was expected to continue drenching states across Mexico even as it dissipated early Friday morning, forecasters said.
Forecasters downgraded Alex from a tropical storm to a tropical depression as it lost steam passing over mountains in central Mexico on Thursday, the National Hurricane Center said. Late in the day, sustained winds were only 30 mph (45 kph).
But states in northern Mexico could continue to see record-setting torrential downpours and flooding, Mexico's National Meteorologic Center said late Thursday. Even as it weakened, the storm caused significant damage in parts of Mexico.
Mexico's official Notimex news agency reported Thursday that the storm killed at least two people in the state of Nuevo Leon. Families in rural areas of the state were stranded on their rooftops as floodwaters rose, Notimex said, and rushing waters from the overflowing Santa Catarina river washed out major roads in the city of Monterrey.
Nuevo Leon Gov. Rodrigo Medina de la Cruz asked federal authorities to declare the state a disaster area Thursday after more than 27 inches (700 mm) of rain fell in 12 hours, the agency said.
"This is an extraordinary phenomenon that has never been seen before, that is going to leave serious consequences in highway and road infrastructure," he said, according to Notimex.
Alex dumped more rain on Mexico than the previous record-holder, Hurricane Gilbert, did in 1988, the National Water Commission said.
The Mexican navy said that it rescued seven people Wednesday from a fishing boat stranded by the storm about 112 nautical miles off the Yucatan peninsula.
At 11 p.m. CT Thursday (midnight ET Friday), Alex was centered about 34 miles (55 kilometers) northeast of Zacatecas, Mexico, moving westward at 11 mph (18 kph), Mexico's weather service said.
The season's first named storm was downgraded earlier Thursday from hurricane status after making landfall Wednesday night as a Category 2 hurricane in the Mexican municipality of Soto la Marina, the National Hurricane Center said.
Even though Alex was centered more than 600 miles from the massive BP oil disaster, officials said the storm could affect cleanup efforts for days because it stirred up heavy seas across the Gulf of Mexico.
