Coastal Flood and High Wind in Delaware, October 2 to 4, 2015

Name: Coastal Flood and High Wind in Delaware, October 2 to 4, 2015
Start: 2015-10-02T09:00
End: 2015-10-04T10:00
Location: Delaware

October 2 to 4, 2015 · NWS PHI · 7 events in 4 counties and zones

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: $25,000
Crop damage: None recorded
Events: 7

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PHI wrote it up.

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.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Oct 2, 3:10 AM EST, 5 hours 50 minutes earlier.

Area forecast discussion, Oct 2, 3:10 AM EST, 5 hours 50 minutes before

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Hazardous weather outlook, Oct 2, 4:08 AM EST, 4 hours 52 minutes before

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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 coastal flood, 3 strong wind, 1 high wind. Local standard time, as filed.

Coastal Flood, Delaware Beaches

When: October 2, 9:00 AM EST to October 3, 3:00 PM EST
Where: Delaware Beaches forecast zone
Property damage: $10,000
Reported by: WLON
Coordinates: 38.683, -75.339 (the zone’s center; the record gives no point)

Coastal Flood, Inland Sussex

When: October 2, 9:00 AM EST to October 3, 3:00 PM EST
Where: Inland Sussex forecast zone
Property damage: $1,000
Reported by: WLON
Coordinates: 38.683, -75.339 (the zone’s center; the record gives no point)

Coastal Flood, Kent

When: October 2, 9:00 AM EST to October 3, 3:00 PM EST
Where: Kent forecast zone
Property damage: $1,000
Reported by: WLON
Coordinates: 39.096, -75.505 (the zone’s center; the record gives no point)

Strong Wind, Inland Sussex

When: October 2, 3:00 PM EST to October 4, 10:00 AM EST
Where: Inland Sussex forecast zone
Measured: 43 kt (49 mph) estimated gust
Property damage: $1,000
Reported by: Mesonet
Coordinates: 38.683, -75.339 (the zone’s center; the record gives no point)

Strong Wind, Kent

When: October 2, 4:00 PM EST to October 4, 1:00 AM EST
Where: Kent forecast zone
Measured: 40 kt (46 mph) estimated gust
Property damage: $1,000
Reported by: Mesonet
Coordinates: 39.096, -75.505 (the zone’s center; the record gives no point)

Strong Wind, New Castle

When: October 2, 4:00 PM EST to October 3, 5:00 PM EST
Where: New Castle forecast zone
Measured: 40 kt (46 mph) estimated gust
Property damage: $1,000
Reported by: Mesonet
Coordinates: 39.578, -75.639 (the zone’s center; the record gives no point)

High Wind, Delaware Beaches

When: October 2, 8:00 PM EST to October 3, 12:00 AM EST
Where: Delaware Beaches forecast zone
Measured: 54 kt (62 mph) measured gust
Property damage: $10,000
Reported by: Buoy
Coordinates: 38.683, -75.339 (the zone’s center; the record gives no point)

What these are

Coastal Flood: Flooding of coastal land by the sea, from storm surge, onshore wind or high tides.
Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Delaware in 2015 Every state in 2015 This day in weather history Warnings in Delaware, October 2015

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 605048, 605049, 605050, 604959, 604960, 604961, 604958.