Hurricane forecasters are tracking two tropical waves in the Atlantic that could be the next areas of concern in the wake of Hurricane Erin. Here’s what the spaghetti models are showing.

Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies. Hurricane Erick, a Pacific storm that made landfall June 19 in Oaxaca, Mexico, also strengthened rapidly, doubling in intensity in less than a day.

Hurricane Erin made a sudden shift in trajectory Wednesday as Category 2 winds raced towards the U.S. East Coast, resulting in closed beaches and a state of emergency being declared in North Carolina.

The National Hurricane Center is monitoring two disturbances in the Atlantic—the first poised to approach the northern Leeward Islands later this week and the second near the Cabo Verde Islands—while Hurricane Erin, now a Category 3, heads away from the Caribbean.

While Erin is expected to take a northward turn in the Atlantic, a new system off the coast of Africa has the National Hurricane Center's attention.

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

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.

It quickly powered up from a tropical storm to a Category 5 in a single day, the National Hurricane Center said.

Forecasters said Erin should begin to slowly weaken as it increased wind shear. However, it's predicted to remain a major hurricane until late next week.

Tropical Storm Erin is forecast to rapidly strengthen into a hurricane this weekend as it nears the northeastern Caribbean and Bahamas, raising concerns for strong winds, heavy rain, and dangerous surf along the islands.

Tropical Storm Erin on Wednesday continued to push west through the Atlantic with it forecast to become the season’s first hurricane, growing to major hurricane strength by the weekend,