Tropical Storm Dalila has formed in the Pacific off southwest Mexico and authorities have issued a tropical storm warning for a swath of that country's coastline.
The U.S. National Hurricane Center in Miami said the fourth tropical storm of the season formed Sunday about 260 miles (420 kilometers) southwest of Acapulco, Mexico, and is moving northward at 10 mph (17 kph). The storm has top sustained winds of 40 mph (65 kph).
Mexico's government issued a tropical storm warning for its Pacific coast region from Punta San Telmo to Manzanillo. The Miami center says the storm is expected to strengthen in the next 48 hours.
Forecasters say tropical storm conditions are expected to first reach the coast early Monday with 1 to 3 inches of rain expected over some areas.