At 5 a.m. Wednesday, Hurricane Julia was upgraded to a Category 4 storm, while her brother, Hurricane Igor, maintained his Category 4 status.
In doing so, Julia also became the strongest hurricane on record so far east.
Although the storm was downgraded to a Category 3 at 5 p.m., this 12-hour period marks only the second time in recorded history that two Category 4 hurricanes were active at the same time in the Atlantic.

As Chris Landsea pointed out in his 2007 paper, it has only been fairly recently that we have been able to track hurricanes in the mid-Atlantic.

There is a lot more information available now. Sometimes it is difficult to differentiate increased information from actual changes to the environment