After briefly weakening, Hurricane Erin has re-intensified into a Category 4 hurricane with sustained winds of 130 mph, according to the National Hurricane Center.

It’s a busy time in the tropics! Major Hurricane Erin and a new disturbance moving off of Africa will need to be watched.

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.

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.

Hurricane Erin is heading for the United States and so, too, could some massive waves, reaching more than 100 feet in height. The major storm, which is currently a Category 3 hurricane, is weakening as it approaches the United States. Still, it could have serious impact on much of the East Coast. ...

Charley roared ashore near Cayo Costa, Florida, or west of Fort Myers, packing maximum sustained winds of 150 mph on the afternoon of Aug. 13, 2004. The intensification of Charley prior to landfall was a worst-case scenario since nearly eight hours earlier over the eastern Gulf, it was a Category 2 with 110 mph winds.