A persistent onshore flow caused periods of heavy rain, strong to high winds, beach erosion, and moderate tidal flooding to occur across Delaware from the 1st through the 4th. Strong winds and minor tidal flooding started with the daytime high tide cycle on the 1st. The winds and minor to moderate tidal flooding both peaked on the 2nd. Slow improvement in conditions occurred through Sunday the 4th, with only some residual minor tidal flooding occurring on the 5th.
Delaware Governor Jack Markell declared a limited State of Emergency for Sussex County at the onset of the widespread and significant coastal flooding on Friday the 2nd. In Sussex County, Delaware State Route 1 was closed at the Indian River Inlet Bridge due to coastal flooding, and Pilottown Road in Lewes was also closed due to flooding. In Kent County, a portion of Fork Landing Road west of Frederica was closed due to flooding, and the intersection of Old State Road and Old Corbit Road in Middletown was impassable and closed due to flooding. Numerous road closures were also reported around Big Stone Beach in Kent County due to tidal flooding. Significant beach erosion occurred along Delaware's southern coast, with minor to moderate damage to dunes being reported. Meanwhile in New Castle County, saturated ground and gusty winds downed a large tree along Weatherhill Drive in Weatherhill Farms west of Wilmington.
Minor tidal flooding began with the day and night high tide cycles on the 1st in Sussex and Kent Counties, escalating to moderate tidal flooding and the highest tides occurring during the daytime high tide cycle on the 2nd. The high tide at Lewes (Breakwater Harbor) reached 7.57 feet above mean lower low water at 106 p.m. EDT on the 2nd. Moderate tidal flooding starts at 7.0 feet above mean lower low water. Moderate tidal flooding continued at Lewes (Breakwater Harbor) with the next two successive high tide cycles, the early morning and early afternoon of the 3rd. Minor tidal flooding then occurred at Lewes with successive early morning and afternoon high tide cycles from the 4th through the 5th. In addition, minor tidal flooding also occurred along the lower part of the tidal Delaware River at Reedy Island, DE with late afternoon high tide cycles on the 3rd and the 4th, affecting portions of the New Castle County coast.
The peak in tidal flooding, especially from the afternoon of the 2nd through the early morning of the 3rd, also coincided with the strongest winds to affect the area as most of the peak wind gusts occurred during this timeframe. Measured wind gusts to affect Delaware included 62 mph at the Lewes NOS buoy (Sussex County), 48 mph at the Sussex County Airport (Sussex County), 46 mph at Indian River Bay (Sussex County), 45 mph at Rehoboth Beach (Sussex County), 43 mph at the New Castle County Airport (New Castle County), and 40 mph at Dover Air Force Base (Kent County).
The tidal flooding and strong winds were caused by a strengthening pressure gradient (difference) between a strong high pressure system building across southeastern Canada and a lingering frontal boundary offshore of the Northeast and Mid Atlantic seaboard. In addition, some moisture, associated with Hurricane Joaquin passing offshore well to the south, interacted with the stalled frontal boundary, which enhanced rainfall amounts somewhat across the area. Storm total rainfall amounts averaged from 2 to 4.5 inches, especially across Sussex and Kent Counties, with the heaviest amounts being recorded near the coast. The pressure gradient then weakened during the day of the 4th as the high pressure across southeast Canada weakened.

High Wind in DELAWARE BEACHES, DELAWARE
From 02-OCT-15 20:00:00 to 03-OCT-15 00:00:00 (EST-5)
Magnitude: 54.00 MG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Buoy

Strong Wind in INLAND SUSSEX, DELAWARE
From 02-OCT-15 15:00:00 to 04-OCT-15 10:00:00 (EST-5)
Magnitude: 43.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in KENT, DELAWARE
From 02-OCT-15 16:00:00 to 04-OCT-15 01:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in NEW CASTLE, DELAWARE
From 02-OCT-15 16:00:00 to 03-OCT-15 17:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Mesonet

Coastal Flood in DELAWARE BEACHES, DELAWARE
From 02-OCT-15 09:00:00 to 03-OCT-15 15:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: WLON

Coastal Flood in INLAND SUSSEX, DELAWARE
From 02-OCT-15 09:00:00 to 03-OCT-15 15:00:00 (EST-5)
Property damage: 1.00K
Crop damage: 0.00K
Reported by: WLON

Coastal Flood in KENT, DELAWARE
From 02-OCT-15 09:00:00 to 03-OCT-15 15:00:00 (EST-5)
Property damage: 1.00K
Crop damage: 0.00K
Reported by: WLON