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.
At 0200 UTC, a weather station in Virac recorded sustained winds of 120 km/h (75 mph) and 941.4 mbar (hPa; 27.80 inHg) pressure.