Tropical Storm Erin has begun strengthening as it streaks west across the Atlantic and is on track to reach hurricane status as soon as Friday, prompting tropical storm watches in the northern Leeward Islands.

Officials in the northern Caribbean are warning of heavy rains and dangerous swells as Tropical Storm Erin approaches the region.

Tropical Storm Erin is on the cusp of strengthening into a hurricane, which it is expected to become later this Friday, as it bears down on the northern Caribbean islands.