A hurricane watch has been issued for parts of the Texas and Mexico coasts ahead of Tropical Storm Dolly.

Forecasters say Dolly has entered the Gulf of Mexico, moving at about 18 miles per hour. The storm has maximum sustained winds near 50 miles per hour.

The National Hurricane Center says the watch in Texas extends from Brownsville to Port O'Connor. The government of Mexico says its hurricane watch goes from Rio San Fernando north to the U.S. border.

A tropical storm watch is also in effect on the Texas coast from north of Port O'Connor to San Luis Pass and from La Pesca, Mexico, to Rio San Fernando.