ROANOKE, Va – Rivers rose rapidly around the Region due to a very saturated ground and deep tropical moisture courtesy of Tropical Storm Michael.
During the height of Michael, rainfall rates of 1-2" per hour were common. Some more extreme rainfall rates were present on a more isolated scale. Due to the wet nature of the ground, most of that water went right back into the Rivers.
The Roanoke River crested a little more than 16 ft Thursday making it the 8th highest crest in recorded history. The flood of record is of course the Flood of '85.
During the Election Day Floods, the Roanoke River jumped to 23.4 ft, putting much of downtown under water. Flood of 1985
The ground this time around was able to handle a little more water than in 1985 and most of the rain fell in the Roanoke Valley and points south.
In 1985, most of the rain was focused along the Roanoke Valley and points north toward the Highlands. All of that rain then had to drain into the Roanoke River causing that catastrophic flooding. It also helped that many places picked up 5-12 inches of rain back in '85.
While the rain was intense over the 72 hours leading up to and during Michael, the duration wasn't close to that of the Flood of '85. Here are some of the rainfall amounts that lead to the flash and river flooding across the region.