A persistent onshore flow caused periods of heavy rain, strong winds, beach erosion and widespread minor tidal flooding to occur across Delaware from the 9th through the 13th. Strong winds and minor tidal flooding started with the daytime high tide cycle on the 9th. The winds and minor tidal flooding both peaked on the 10th, with very slow improvement in conditions through Sunday the 13th on Columbus Day weekend and not so coincidentally the last day that minor tidal flooding occurred.
In Sussex County, minor tidal flooding affected roadways in the Long Neck area. Roadway tidal flooding occurred in and around Angola and Oak Orchard. Water was over some bulkheads. In Milton, minor tidal flooding closed Prime Hook Road through the Back Bay Cove. The roadway remained closed for a couple of days. It was reopened after debris was removed from it. The Delaware Department of Transportation provided residents of Prime Hook Road access to their homes. The high tides reached the support pilings of homes at Primehook Beach. Broadkill Road (Delaware State Route 16) was also flooded.
In Kent County, minor tidal flooding affected Bowers Beach. A dune breach occurred. A parking lot off of Murderkill Avenue was flooded. Scattered street flooding and street closings occurred along Delaware Bay between Dover and Milford. This included Port Mahon Road. The Delaware State University cancelled some outdoor activities scheduled for the 11th and 12th. In New Castle County, The strong winds caused wave action to lap over a sea wall in Bay View Beach south of Port Penn.
While minor tidal flooding occurred during the daytime high tide cycles from the 9th through the 13th in Kent and Sussex Counties, the highest tides occurred during the daytime high tide cycle on the 10th. The high tide at Lewes (Breakwater Harbor) reached 6.77 feet above mean lower low water. Minor tidal flooding starts at 6.0 feet above mean lower low water. This also coincided with the strongest winds to affect the area as most of the peak wind gusts occurred during the first half of the day on the 10th and included 50 mph at Dewey Beach (Sussex County), 49 mph in Lewes (Sussex County) and 39 mph in Indian River (Sussex County). The strong winds blew sand into the left lane of northbound Delaware State Route 1 near the Indian River Inlet Bridge.
The tidal flooding and strong winds were caused by the pressure gradient (difference) between a high pressure system over New England and a low pressure system along the Atlantic seaboard. This low initially formed on a cold front in the Gulf of Mexico on the 7th. Some of the moisture associated with Tropical Storm Karen was ingested into this system. This low pressure system moved to the Georgia coast on the morning of the 8th and the North Carolina coast on the morning of the 9th. This low pressure system remained near the Outer Banks of North Carolina into the morning of the 10th (when the pressure difference between it and the high pressure system over New England peaked) before slowly weakening and drifting north to the Delmarva coastal waters on the 11th and 12th. A new high pressure system building into New England on the 13th then started shoving the weakening low pressure system southward later in the day on the 13th and into the 14th.