Cristobal to become tropical depression by Thursday, says NHC

Tropical Storm Cristobal is causing heavy rainfall and life-threatening flooding in parts of Mexico, but could weaken to a tropical depression by Thursday evening, the U.S. National Hurricane Center (NHC) said.

Cristobal was about 20 miles (35 km) south of Ciudad Del Carmen, Mexico, packing maximum sustained winds of 45 mph (75 kph), the Miami-based weather forecaster said in an advisory on Wednesday.

"Some re-strengthening is expected to begin on Friday," NHC added.