A tropical depression took aim at the Pacific coast of Mexico on Saturday, threatening heavy rains in a broad swath of western Mexico near the same area where other storms have caused major flooding over the past couple of months.
Tropical depression Eighteen-E was churning over the Pacific Ocean 360 miles (580 km) south of the resort city of Los Cabos at the southern tip of the Baja California peninsula and could become a tropical storm by Saturday night or Sunday, the Miami-based U.S. National Hurricane Center said.
The weather system was traveling west-northwest at 6 miles per hour (9 kph) with maximum sustained winds of 35 mph (55 kph), the NHC said in an advisory.
If the system becomes a tropical storm - with sustained winds of at least 39 mph (63 kph) - it will be called Sonia.
Mexico's government issued a tropical storm watch for a stretch of the coast from the port of Topolobampo south to the town of La Cruz, both in Sinaloa state.
The slow-moving tropical depression could unleash heavy rainfall in the western states of Colima, Michoacan, Nayarit and Jalisco, Mexico's national water commission said on Saturday.
The NHC said the center of the system will pass near Los Cabos by Sunday night, and then approach the mainland on Monday.
All of Mexico's major Pacific ports remained open, according to the country's Communications and Transportation Ministry.
In September, Mexico suffered its worst flooding since records began when storms Manuel and Ingrid converged from the Pacific and the Gulf of Mexico, killing more than 150 people and causing damage estimated at around $6 billion.
Last month, Hurricane Raymond caused some flooding as it approached the Pacific resort cities of Acapulco and Zihuantanejo, but no deaths or major damage was reported.