Simplify the following text for a Grade 10 native English-speaking person.
Original: After peaking in intensity , Tip weakened to a 230 km\/h ( 145 mph ) typhoon and remained at that intensity for several days as it continued west-northwestward .
Simplified: After hitting its peak strength , Tip weakened to a 230 km\/h ( 145 mph ) typhoon and stayed at that intensity for several days as it moved west-northwest .