An area of low pressure being monitored in the western Gulf developed into a tropical depression Saturday that forecasters said could strengthen into a tropical storm by the time it makes landfall in Mexico.

The depression is expected to strengthen over the next 24 hours, likely to hit the Mexican coastline Monday as Tropical Storm Barry.

A tropical storm warning was in effect Sunday for parts of eastern Mexico due to the system known as Tropical Depression Two that formed in the Gulf. As of 5 a.m., it was about 50 miles north-northeast of Veracruz, Mexico, with maximum sustained winds at 35 mph. If its winds reach 39 or above, it would become Tropical Storm Barry.