The key to the severity of impacts in the Leeward Islands and Puerto Rico from strengthening Erin depends on how soon a turn to the northwest occurs with a near-miss versus a direct hit.

Tropical Storm Erin is nearly at hurricane strength Thursday night, its western path putting islands in the far eastern Caribbean under tropical storm watches, according to the National Hurricane

The National Hurricane Center (NHC) has warned that Tropical Storm Erin is expected to strengthen and could become a major hurricane over the weekend as it shifts just north of the northern Leeward Islands,