After reaching hurricane status , Ivan began to rapidly intensify with continued favorable conditions , and in an 18 hour period the pressure dropped 39 mbar ( 1.15 inHg ) as the winds increased by 60 mph ( 95 km\/h ) ; early on September 6 Ivan attained an initial peak intensity of 135 mph ( 215 km\/h ) while located about 825 miles ( 1330 km ) east of the island of Tobago in the southern Lesser Antilles .
After reaching hurricane status , Ivan began to rapidly intensify with continued favorable conditions , and in an 18 hour period the pressure dropped 39 mbar ( 1.15 inHg ) as the winds increased by 60 mph ( 95 km\/h ) ; early on September 6 Ivan reached its first peak intensity of 135 mph ( 215 km\/h ) while about 825 miles ( 1330 km ) east of the island of Tobago in the southern Lesser Antilles .