Simplify the following text for a Grade 12 native English-speaking person.
Original: The depression quickly strengthened and reached hurricane strength on September 11 , peaked as a Category 2 hurricane on September 12 as it made a half circle , weakened to a Category 1 on September 16 and bounced back the way it came .
Simplified: The depression quickly strengthened and reached hurricane strength on September 11 ; Earl reached its strongest point on September 12 , as a Category 2 hurricane as it traveled in a half circle .