Between 4 and 5 pm on September 16, 1999, the center of Hurricane Floyd passed directly over an automated coastal monitoring station located on the beach in Avalon, New Jersey.  The monitoring station is part of the New Jersey Coastal Monitoring Network operated by Stevens Institute of Technology.  Tropical Depression Floyd formed on September 7th in the western Atlantic. By September 10, Floyd reached hurricane strength and its center of circulation was located approximately 200 miles east-northeast of Barbuda in the northern Leeward Islands. Over the next two days Floyd moved west-northwest, strengthening to a category 4 hurricane. On the morning of September 15th, Floyd was located about 300 miles south of Wilmington, North Carolina. Floyd took a turn to the north during the day on the 15th and decreased in intensity to a category 2 hurricane. At 3 am EDT Floyd made landfall at Cape Fear, North Carolina.
 
 

After landfall, hurricane turned to the north-northeast and increased in forward speed to between 20 and 25 mph. By 11 am the center of Floyd moved northeastward off of the Norfolk Va. coastline back into the Atlantic Ocean. The hurricane traveled up the Maryland-Delaware coast and by 5 pm EDT the center of Floyd was located over Atlantic City, NJ (25 miles northeast of the Avalon Coastal Monitoring Station).
 
 

The data recorded by the Avalon Coastal Monitoring Station is presented below as time histories (Sept. 15 to Sept. 18) of barometric pressure, wind speed, wind gusts, wind direction, water depth above the wave/tide gauge, wave height and wave period. The wave/tide gauge is located approximately 1/4-mile offshore in an average water depth of 13.1 ft MLLW.
 
 

As Floyd was making landfall at Cape Fear during the early morning hours of the 16th, the wind flow over southern New Jersey was from the northeast at 20 knots gusting to 30 knots. As the morning progressed, the barometric pressure began to decrease from 1010 mb down to 992 mb by twelve noon. Sustained wind speeds increased to 30 knots with gusts to 40 knots from the east-southeast as the storm moved northeastward up the coast. In response to the increase in the local wind field, the wave heights along the coast increased from 4 to 6 ft with dominant wave periods of between 5 to 7 seconds.

By 2 pm, the center of Floyd was less than 100 nautical miles southwest of the Avalon monitoring station. Sustained winds of greater than 30 knots out of the southwest produced a prolonged high tide (the predicted high tide was to occur at 12:46 pm EDT at Atlantic City, see below) and waves of up to 6.5 ft in height.

After 2 pm, the barometric pressure began to drop rapidly, falling 4 mb per hour. The center of Hurricane Floyd passed over Avalon between 4 and 5 pm EDT. In the center of the eye, the barometric pressure bottomed out at 978.3 mb and the winds decreased to below 10 knots.
 
 

After the passage of the eye, the barometric pressure increased as rapidly as it fell and the winds clocked around from the east-southeast to the west-southwest. In response to this 180 degree wind shift, the local wind sea decreased 3 ft over the next 6 hours and the dominant wave period increased from 8 to 14 seconds, indicating that swell generated from the southern quadrants of the hurricane had replaced the local sea. The easterly directed wind field persisted for over 24 hours after the passage of Floyd, generating a significant set-down in the local sea surface elevation along the coast.
 
 

The predicted tidal elevation relative to MLLW at Atlantic City and the measured tidal elevations from Atlantic City and Avalon are plotted below.

From the tidal plot it is clear that the westerly directed wind field began to elevate the sea surface elevation along the coast well in advance of the Hurricane. By mid-day on the 15th, the tides were running approximately 0.5 ft above predicted levels. By mid-night on the 15th, the sea surface elevation was running 1 ft. above predicted tide levels. As Floyd moved northeastward along the coast during the day on the 16th, a tidal surge of approximately 2 ft. proceeded the storm. After the passage of the eye, a rapid set-down in sea surface elevation occurred that persisted for 36 hours. Tides averaged approximately 1 ft. below the predicted tidal elevation during the period.
 
 

The most damaging aspect of Hurricane Floyd was not felt along the New Jersey coast. Hurricane Floyd caused rainfall ranging from 5 to 14 inches through the State on September 16-17. The heaviest rainfall was in a band from Trenton northeast through Bergen County. The Raritan River at Bound Brook crested higher than any flood since at least 1800 and probably since the area was settled. Over 35 new peaks of records were set, mostly in the Hackensack, Saddle, Elizabeth, Rahway and Raritan River basins (see USGS). The satellite image above shows how the moisture associated with Hurricane Floyd (the center of circulation is approximately over Norfolk Va. in the image) interacted with the moisture located to the east of a cold front situated over the eastern Great Lakes to produce extremely heavy rainfall over central New Jersey. Below is a bar graph showing the peak stage recorded on the Raritan River at Bound Brook. The River crested approximately 15 ft above flood stage and 4.66 ft above the previously recorded maximum stage. This resulted in severe flooding and property damage in the communities of Bound Brook, Manville, and many more communities along the bank of the Raritan River.