Edouard originated from a tropical wave
that was already well-marked by a spiral-shaped mass of convective
clouds
while moving across
western Africa on 17-18 August. The wave crossed the west coast of
Africa
early on the 19th,
accompanied by a 45-knot mid-tropospheric jet seen in rawinsonde data.
Observations from Dakar and
nearby stations showed thunderstorms and squalls, along with 24-hour
surface
pressure
falls on the order of 3 to 4 mb as the wave passed. Soon after entering
the
eastern
tropical Atlantic, ship reports showed the presence of a large surface
circulation. It is
estimated that a tropical depression
formed around 1800 UTC on 19 August, centered about 300 n mi southeast
of
the Cape Verde Islands. This was the first in a series of four tropical
cyclones that would form over the eastern Atlantic from waves that moved
off
the west
coast of Africa during a two-week span in late August and early September
of 1996.
Three of these systems, Edouard, Fran, and Hortense eventually became
category
three (or stronger) hurricanes.
Initially, it appeared that the westward-moving tropical cyclone would
soon take a
northwestward turn in response to a weakness in the subtropical ridge
over
the eastern
Atlantic. However, the subtropical ridge remained strong enough to the
north of the
system to keep it on a generally westward track into the central
tropical
Atlantic.
Higher-level winds favored intensification of the cyclone, as an
upper-tropospheric anticyclone became well established over the area.
The
system became Tropical Storm Edouard
early on 22 August, and strengthened into a hurricane around 1200 UTC
the
following day,
when a banding-type eye
was noted in satellite pictures.
When the hurricane neared 45W longitude on the 24th, a deep-layer cyclone
to the
east of Bermuda began to create a weakness in the subtropical ridge. In
response to
this, Edouard's direction of motion changed from westward to
west-northwestward.
Meanwhile, intensification continued, and Edouard's winds strengthened
to
100 knots
on the 24th and to 125 knots on the 25th, making it a category four
hurricane. The
latter wind speed was the maximum intensity, and a similar wind speed is
estimated on
the 26th and also around 0000 UTC on the 28th. From the 26th to the
28th, some
fluctuations in intensity were noted, apparently as the result of
eyewall
replacement
cycles and occasional doses of stronger vertical shear over the area.
Nonetheless,
Edouard maintained 115 knot or greater winds throughout the above period
.
The final
deepening episode in Edouard was observed late on 29-30 August. During
that event,
three concentric eyewalls were indicated by aerial reconnaissance
observations.
Overall, Edouard remained a powerful, 100-knot or stronger hurricane for
a
very long
time - from 24 August until early on 1 September.
Edouard moved relentlessly towards the west-northwest, at around 12
knots, until
the 29th of August. This track kept the hurricane well to the northeast
and
north of the
islands of the northeastern Caribbean Sea. On the 29th, a
mid-tropospheric trough
became established near the U.S. east coast, creating a more northward
steering
component for Edouard. Slowing its forward speed slightly, the hurricane
turned
northwestward, and then northward, while gradually weakening. The
cyclone passed
about midway between Cape Hatteras and Bermuda on 1 September, and then
started
moving slightly east of north. Late on the 1st, the hurricane wobbled
toward the north,
in the general direction of southeastern New England. However, early on
the 2nd,
Edouard veered sharply toward the northeast, and the center of the
hurricane passed
about 75 n mi southeast of Nantucket island around 0900 UTC, the closest
point of
approach to the United States. Maximum winds had diminished to near 70
knots by
that time.
Edouard weakened to a tropical storm near 0000 UTC on the 3rd, and
became
extratropical shortly thereafter.
The storm's motion became east-northeastward, keeping the center south
of
Nova Scotia,
and, later, well offshore of Newfoundland. Edouard's remnant low was
drawn
around and
into the circulation of a larger extratropical cyclone on the 6th, and
was
absorbed by
this bigger system by 0000 UTC 7 September.
Most of the aircraft reconnaissance flights into Edouard were
accomplished
by the "Hurricane Hunters" of the U.S. Air Force Reserves.
The Hurricane Hunters flew 15 missions, and made 66 center fixes.
NOAA aircraft provided four additional fixes.
The highest wind speed reported was 140 knots (at 700 mb) at 0003 UTC 28
August.
Lowest central pressure reported was 934 mb at 1727 UTC 30 August.
However, the
highest wind reported by aircraft around that time was 134 knots.
Subjective and
objective Dvorak intensity estimates indicate that Edouard was stronger
on 25-26
August, and also at 0000 UTC 28 August, than it was at the time of the
minimum
aircraft-reported pressure. At the latter time, the hurricane appeared
considerably less
well-organized on satellite images than on the earlier days.
Since Edouard crossed over the New York shipping channels, there was a large
number of encounters by vessels at sea with this hurricane.
The hurricane came close enough to New England to produce sustained winds of
tropical storm force at Nantucket Island and the Cape Cod area. Wind
gusts to
hurricane force were reported at Nantucket. In addition, there were
unofficial
reports of wind gusts to 90 mph at Nantucket, 80 mph at Martha's
Vineyard, and 77
mph on Cape Cod.
Large swells, minor beach erosion, and some coastal flooding, presumably
minor
as well, occurred along the coast from North Carolina northward through
Maine.
Two deaths have been directly attributed to Edouard. A 71-year old man died when his boat capsized in heavy surf in Great Egg Harbor Inlet, south of Atlantic City, New Jersey. A 28-year old man drowned while surfing at Lavallette, northeast of Tom's River, New Jersey. Additionally, a 44-year old man suffered a broken neck (but survived) while surfing near Atlantic City. Overall, the effects of Edouard on land were apparently minor. Most of the damage was to boats at Martha's Vineyard and Nantucket.