Hurricane Dolly churned into a Category 2 storm as its eye neared the Texas-Mexico border Wednesday, bringing fierce winds and heavy rains that blew down signs, damaged an apartment complex, and knocked out electricity to thousands.

Forecasters warned of up to 15 inches of rain that could produce flooding and breach levees in the heavily populated Rio Grande Valley. Thunderstorms were attributed to Dolly as far away as Houston, 400 miles up the Texas coastline.

In Mexico, fields were filling with water, palm trees were bent over in the wind, and beaches were closed to the public.

Dolly, pictured at 1:20 p.m., July 23.

Cities and counties in the Rio Grande Valley were bracing for massive flooding and levee breaks. Tornado watches were in effect for coastal counties between Corpus Christi and Houston until Wednesday afternoon.

The U.S. Census Bureau said that based on Dolly's projected path, about 1.5 million Texans could feel the storm's effects.

Gov. Rick Perry declared 14 south Texas counties disaster areas, allowing state resources to be used to send equipment and emergency workers to areas in the storm's path.