Tropical Storm Barbara is strengthening off Mexico’s Pacific coast and could become a hurricane by Monday, according to the U.S. National Hurricane Center.

Centered southwest of Zihuatanejo, the storm has 65 mph winds and is moving west-northwest.

While it’s expected to stay at sea, heavy rain may cause flooding and mudslides in parts of western Mexico, the Associated Press has reported.

Coastal areas may also face dangerous surf and rip currents.

Written by B.C. Begley