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.

Tropical Storm Erin's path puts some homeowners at heightened risk, as the storm starts building into a hurricane tracked by meteorologists.

Erin briefly became a Category 5 hurricane over the weekend and weakened to Category 3 status as it moved north and west of Puerto Rico this weekend. It is now a Category 4 storm and will be moving more north in the next few days.

Tropical Storm and Storm Surge Watches have been issued for portions of North Carolina’s Outer Banks as extremely dangerous Hurricane Erin continues to barrel across the Atlantic as a major Category 4 hurricane.

The NWS Newport/Morehead City NC issued a tropical storm watch at 4:50 p.m. on Monday in effect until Tuesday at 2 a.m. for Hatteras Island.

A tropical storm watch was issued by the NWS Newport/Morehead City NC on Monday at 4:50 p.m. in effect until Tuesday at 2 a.m. for Ocracoke Island.

The chances that the storm will make landfall in the U.S. have increased slightly after the path shifted south.

A hurricane's category only measures wind speed, not how far those winds extend from the center. The size of a storm's wind field is crucial for predicting storm surge and overall reach.