MANAGUA, Nicaragua—Tropical Storm Alma slammed into northwest Nicaragua Thursday as the first such storm of the eastern Pacific season, forcing evacuations and flooding low-lying areas along Central America’s coastline.

The storm hit land near the colonial city of Leon, where houses were destroyed and power was knocked out.

Nicaragua’s Radio Ya reported that a 30-year-old man was electrocuted in Trasbayo, 40 miles southeast of Managua, after a power line snapped under high winds.

The storm was expected to weaken before hitting Guatemala or Belize late today or Saturday.