Typhoon Choi-wan was a powerful typhoon Catastrophe that became Becoming the first Category 5 equivalent-super typhoon to form during the 2009 Pacific typhoon season .

By September 12 , the depression intensified Cause_change_of_strength into a tropical storm , at which time it was given Giving the name Choi-wan .

Choi-wan attained Getting its peak intensity on September 15 , as it moved Motion through the Northern Mariana Islands with the Japan Meteorological Agency reporting Reporting peak windspeeds of 195 km/h ( 120 mph ) .

By September 19 , Choi-wan rapidly weakened Cause_change_of_strength as strong wind shear caused Causation convection to diminish .

Despite the intensity of Choi-wan when it passed Motion_directional through the Northern Mariana Islands , no casualties were reported Reporting .