Ike's location in a region with little wind shear allowed the storm to intensify rapidly despite unfavorable upper-level winds to the north, reaching major hurricane status six hours after it was designated as a hurricane. The National Hurricane Center (NHC) estimates that if not for the presence of this wind pattern, Ike would have strengthened further and reached catastrophic strength by the time it made landfall. Ike is believed to be the strongest hurricane on record to make landfall in Texas. It swept across the state as a Category 4 storm with 125 mph (205 kph) winds before moving into Louisiana where it caused more damage as an extratropical storm. Ike formed on September 6 over the far eastern Atlantic Ocean as a tropical depression. Little activity was noted until it began gaining strength several days later when it reached tropical storm status on the 9th. Rapid intensification followed, and by 12:00 PM EDT on the 6th, Ike had intensified into a hurricane. By this time, it had already begun moving toward the west-northwest at 17 mph (28 km/h), so it didn't threaten any land masses but remained a powerful hurricane as it moved over warm waters. By the morning of the 7th, the center of Ike passed over Ireland, causing heavy rainfall and strong winds that destroyed many trees and power lines.