MEXICO CITY (AP) — A likely tropical storm headed for a slog across Central America on Friday and potential development into a hurricane after reemerging in the Pacific.

The U.S. National Hurricane Center said that Potential Tropical Cyclone Two was finally on the cusp of becoming a tropical storm on a track for the general Nicaragua-Costa Rica border region. It was expected to cause significant flooding, with rains of up to 8 inches (about 200 millimeters), and even more in isolated places.

It had maximum sustained winds of 40 mph (65 kph) and was centered about 315 miles (505 kilometers) east of Bluefields on Nicaragua’s Atlantic coast, while moving to the west at 18 mph (30 kph).

A tropical storm warning was in effect for Colombia’s San Andres Island and from Cablo Blanco in Costa Rica northward to Puerto Sandino in Nicaragua.

The Hurricane Center said it was projected to emerge over the Pacific on Saturday and gain force while moving over the Pacific roughly parallel to the coast over the following days.

The fast-moving disturbance has been drenching parts of the Caribbean region since Monday without ever meeting the criteria for a named tropical storm.