The overall synoptic pattern leading into the flooding event was typical of past significant flooding events in the mid-Atlantic region during the late summer months where a tropical system interacts with a frontal boundary.  As Tropical Storm Ernesto moved across Florida on Wednesday August 30^th producing heavy rain along its track, heavy rain also fell across the Carolinas and Virginia along the frontal boundary.  By September 1^st, Ernesto moved into the Carolinas bringing a second round of heavy rainfall. 

Surface Analysis for 21Z August 30, 2006.  Note the surface front from the Carolinas to the Central Gulf Coast was the primary focus for heavy rain before Ernesto moved Northward on the September 1^st and 2^nd.

Ernesto tracked across Florida before moving out into the Atlantic during the last few days in August. A second landfall in the Carolinas and Virginia occurred early on the 1^st of September.

Figure1                                     Figure 2

Figure1 - Regional radar late in the day on Wednesday August 30^th depicted the large area of heavy rainfall across southern and central Florida associated with Ernesto.  Additional heavy rains fell across the southern Virginia through the Carolinas and across parts of Alabama and Georgia.  The heavy rains in the Carolinas would set the stage for significant flooding given a tropical system.

Figure 2 - Regional radar early Friday September 1^st depicted the widespread heavy rainfall across eastern North Carolina and eastern Virginia associated with Ernesto.  With soils nearly saturated from the past few days rainfall, the additional rainfall from Ernesto lead to efficient runoff and flooding.