Hurricane Erin formed in the Atlantic Aug. 15 and rapidly strengthened to a catastrophic Category 5 storm with 160 mph winds on Saturday, Aug. 16, according to the latest advisory from the National Hurricane Center.

5 p.m. Update: Erin is now organizing and strengthening over the Central Atlantic. Erin is expected to become at least a Catgory 3 hurricane but missing Puerto Rico to the north and staying well east of Florida. It is expected to reach Jacksonville’s latitude about early Wednesday, resulting in some rough seas and surf at area beaches next week.

Hurricane season spans from June 1 to November 30. Here’s what you should know before Erin or any future storm approaches land.