Simplify the following text for a Grade 7 native English-speaking person.
Original: Later that day , the storm reached hurricane status ; shortly thereafter , it rapidly strengthening into a 140 mph ( 220 km\/h ) category 4 hurricane .
Simplified: It reached hurricane status on August 30 and reach category 4 strength on September 2 . The next day Luis reached it 's highest winds of 140 mph making it a Category 4 .