MIAMI, Florida (CNN) -- Tropical Storm Dolly intensified early Tuesday in the western Gulf of Mexico, forecasters with the National Hurricane Center said.
Tropical Storm Dolly was headed toward Texas and Mexico at 8:45 p.m. ET on Monday.
A flurry of warnings were issued along the coasts of Texas and Mexico overnight. The center's tracking map shows the storm coming ashore as a hurricane on Wednesday, around the Texas-Mexico border.
Hurricane warnings were in effect along about 200 miles of coastline from Rio San Fernando in Mexico northward to Port O'Connor, Texas. A hurricane warning means that hurricane conditions are expected within the warning area within the next 24 hours.
Tropical storm warnings stretched south of Rio San Fernando to La Pesca, Mexico and north of Port O'Connor to San Luis Pass, Texas.
At 5 a.m., the storm with its 60 mph winds was centered about 295 miles (475 km) southeast of Brownsville, Texas.
The storm's was moving to the west near 15 mph, but was expected to gradually turn toward the northwest by Wednesday. Dolly's forward motion was forecast to slow, giving the storm more time to intensify over the warm gulf waters. iReport.com: Are you ready for hurricane season?
"All odds are now that we're looking at Category 1 hurricane on the Texas coast by midday Wednesday," said Bill Read, director of the hurricane center. hurricane center
A Category 1 hurricane carries sustained winds between 74-95 mph (119-153 km/h.)
Dolly is expected to produce total rain accumulations of 4 to 8 inches, with isolated amounts of 15 inches over much of south Texas and northeastern Mexico over the next few days, forecasters said. Watch as Dolly is expected to strengthen over the Gulf of Mexico »
Meanwhile, Tropical Storm Cristobal paralleled the Atlantic Seaboard as it slowly began losing steam.
At 5 a.m., Cristobal was speeding toward the east-northeast near 21 mph, about 485 miles (780 km) northeast of Cape Hatteras, North Carolina and about 450 miles (720 km) south-southwest of Halifax, Nova Scotia.
The storm was packing 60 mph winds, but is expected to weaken over the next 24 hours.
The Atlantic hurricane season began June 1 and runs through November.