Tracking west-northwestward in advance of a trough over the eastern United States, the system did not resemble a typical hurricane on satellite imagery, with a low-level center outside of the deepest convection. The system turned towards the northwest and simultaneously slowed in motion by August 27 as a second mid-latitude trough passed to its north. Though wind shear remained unfavorable initially, it began to lessen on August 28 as an anticyclone developed aloft. At 12:00 UTC, Dennis was upgraded to a Category 2 hurricane on the Saffir–Simpson scale and reached peak winds of 105 mph (165 km/h), though its lowest barometric pressure was recorded until 06:00 UTC on August 30. Despite this intensity, the hurricane's eye was large, up to 30-40 mi (50-65 km) wide, and several fixes from the Hurricane Hunters did not indicate the presence of one at all. The system also became unusually large, with its radius of maximum sustained winds extending up to 70-85 mi (110-130 km) wide. Following peak intensity, Dennis accelerated towards the northeastward in response to the secondary trough, barely missing the Outer Banks. By August 31, steering currents collapsed and the hurricane began to aimlessly drift east of Cape Hatteras, North Carolina.