Hurricane Erin has reintensified into a Category 4 storm on Aug. 18, according to the National Hurricane Center. See where Erin is headed.

Some fluctuations in intensity are expected over the next couple of days due to inner-core structural changes.

The Saffir-Simpson Hurricane Wind Scale is a rating from one to five based only on a hurricane's maximum sustained wind speed. It does not take into account other hazards, including storm surge, ...