MIAMI (AP) — Tropical Storm Boris formed Monday and is expected to bring heavy rain, flooding and possible mudslides to parts of southern Mexico’s Pacific coast, the U.S. National Hurricane Center said.

Boris was located about 85 miles (135 kilometers) southeast of Acapulco and 50 miles (80 kilometers) southwest of Punta Maldonado, according to the Miami-based weather center. The storm had maximum sustained winds of 40 mph (65 kph) and was moving northeast at 5 mph (7 kph).

Boris was expected to make a turn to the north, bringing rainfall of 4 to 10 inches (10 to 25 centimeters) to coastal portions of the states of Guerrero and Oaxaca through Monday night.

“This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain,” the center said.

A tropical storm warning was in effect from Laguna de Chacahua in Oaxaca to Tecpan de Galeana in Guerrera, with tropical storm conditions expected in the area within 24 hours.

Boris is the second named storm of the Pacific hurricane season, which started May 15. Tropical Storm Amanda formed June 3 far out to sea, posing no threat to land.

The Atlantic hurricane season began June 1, but no cyclones have formed in that basin yet this year.