McALLEN, Texas — Dolly spun into a hurricane Tuesday, heading toward the U.S.-Mexico border and the heavily populated Rio Grande Valley, where officials feared heavy rains could cause massive flooding and levee breaks.
Dolly was upgraded from a tropical storm Tuesday afternoon with sustained winds near 75 mph, and some strengthening of the Category 1 storm was forecast before it makes landfall today. At 11 p.m., the storm's center was about 110 miles east-southeast of Brownsville, moving northwest at about 9 mph.
A hurricane warning is in effect for the coast of Texas from Brownsville to Corpus Christi and in Mexico from Rio San Fernando northward.
In Mexico, Tamaulipas Gov. Eugenio Hernandez said officials planned to evacuate 23,000 people to government shelters in Matamoros, Soto La Marina and San Fernando.
Texas officials urged residents to move away from the Rio Grande levees because if Dolly continues to follow the same path as 1967's Hurricane Beulah, "the levees are not going to hold that much water," said Cameron County emergency management coordinator Johnny Cavazos.
Forecasters predicted Dolly would dump 15 to 20 inches of rain and bring coastal storm surge flooding of 4 to 6 feet above normal high tide levels.
Gov. Rick Perry declared 14 South Texas counties disasters, allowing state resources to be used to send equipment and workers to areas.
The storm and the levees that have deteriorated in the 41 years since Beulah swept up the Rio Grande pose a major flooding threat to low-lying counties along the border. Beulah spawned more than 100 tornadoes and dumped 36 inches of rain in some areas, killing 58 people and causing more than $1-billion damage.
The International Boundary and Water Commission, which operates a series of levees, dams and floodways in the lower Rio Grande Valley, put its personnel on standby alert.
The Navy began flying 104 of its aircraft out of Naval Air Station Corpus Christi to bases inland. Other aircraft will be sheltered on base in hangars and no evacuation was planned.
Maj. Jose Rivera of the Texas Army National Guard said troops were preparing in Houston, Austin and San Antonio, after Perry called up 1,200 Guard members.
Immigration and Customs Enforcement was evacuating its Port Isabel Detention Center, said spokeswoman Nina Pruneda. Fewer than 1,000 people were being sent to other detention centers in Texas.
In the Gulf of Mexico, Shell Oil evacuated workers from oil rigs, but said it didn't expect production to be affected.