Labelled the "perfect storm" by the National Weather
Service, the storm sank the swordfishing boat Andrea Gail,
whose story became the basis for the currently best-selling novel
"The Perfect Storm" by Sebastian Junger. A little-known
and bizarre ending came to this monster, which came to be known as
the Halloween Storm. To tell this incredible story in its entirety,
I've included some Satellite Eye Imagery and explicit storm detail
for those who would like to know more about the storm including its
heading, damage report, and a step by step progress of the storm as
it wreaks havok among the coastal cities on the North East section
of the U.S. Special
thanks to The
National Climatic Data Center
For a more concise and less detailed overview on the storm,
check out USA
TODAY's article that ran in the paper at the time of the storm.
"The
Perfect Storm"
Conditions at the Time of the Image
The color-enhanced
infrared image of 1200 UTC October 30, 1991 depicts a monster storm
off the Eastern Seaboard, which was described by the National
Weather Service as the "perfect storm." In this image, the
storm was at its peak intensity. The storm became subtropical thirty
hours later, just before the inner core of the storm developed into
a topical storm and later an unnamed hurricane.
History of the
Storm
Late October and
November are months with weather in rapid transition in the eastern
U.S. To the west, large fresh cold air masses from Canada begin to
envelope the Midwest on a regular basis. To the east, the Atlantic
Ocean is slower to lose its stored summer heat than the continent,
and hurricanes sometimes form over the warm waters. The contrast
between two very dissimilar air masses often results in massive
storms just offshore of North America. These tempests, called
"Nor'easters" in the Atlantic states, have sunk many ocean
vessels, and this storm lived up to the reputation of being severe.
On October 28,
1991, a extratropical cyclone developed along a cold front which had
moved off the Northeast coast of the U.S. By 1800 UTC, this low was
located a few hundred miles east of the coast of Nova Scotia. With
strong upper air support, the low rapidly deepened and became the
dominant weather feature in the Western Atlantic. Hurricane Grace,
which had formed on October 27 from a pre-existing subtropical storm
and was initially moving northwestward, made a hairpin turn to the
east in response to the strong, westerly deep-layer mean flow on the
southern flank of the developing extratropical low. Grace was a
large system and it was already generating large swells ranging in
size from about 15 feet offshore of North Carolina to about 10 feet
near the Florida coastline.
As the low pressure
continued to deepen on October 29, Grace became only a secondary
contributor to the phenomenal sea conditions which developed over
the Western Atlantic during the next few days. At 1800 UTC on the
29th, the vigorous cold front from the extratropical low undercut
and quickly destroyed Grace's low level circulation east of Bermuda
(Note the red and yellow area east of Charleston, SC in Figure 1).
The remnant mid- and upper-level moisture from Grace became caught
up in the outer part of the extratropical storm center's
circulation, far from the storm's center. By the next day these
remnants had become indistinguishable. The center of the
extratropical low drifted southeastward and then southwestward,
deepening all the time. It reached peak intensity of 972 mb and
maximum sustained winds of 60 knots at 1200 UTC on October 30, when
it was located about 340 n mi south of Halifax, Nova Scotia (See
Event Discussion image above). After reaching peak intensity on
October 30, the low retrograded southwestward on October 31 (Note
swirl off Delmarva Peninsula in Figure 2 below), and then southward
as the central pressure rose to about 998 mb by 0000 UTC on November
1.
65 Knot Winds/ 39 Foot Wave Heights
During the early
phase of the storm's history, a strong high pressure center extended
from the Gulf of Mexico northeastward along the Appalachians into
Greenland. Strong winds were generated from the tight pressure
gradient between a strong high pressure center in eastern Canada
(1043 mb) and the surface low. Phenomenal seas and strong winds and
waves along the eastern U.S. coastline occurred at this time.
Several vessels passed close to the extratropical storm center on
October 30 and reported winds of 50-60 knots. NOAA buoy 44011
located at 41.1 degrees N, 66.6 degrees W reported maximum sustained
winds of 49 kt with gusts to 65 kt and a significant wave height of
39 feet near 1500 UTC. Buoy 44008 located at 40.5 degrees N, 69.5
degrees W reported maximum sustained winds of 53 kt with gusts to
63kt and a significant wave height of 31 feet near 0000 UTC on
October 31. Other unsubstantiated observations reported winds and
waves considerably higher.
North Carolina's
coast was lashed with occasional winds of 35 to 45 mph for five
consecutive days. In New England on October 30-31, wind gusts of
above hurricane force pounded the Massachusetts coastline.
Representative peak gusts included: 78 mph at Chatham NWS, 74 mph at
Thatcher Island, 68 mph at Marblehead, 64 mph at Blue Hill
Observatory (all in Massachusetts) and 63 mph at Newport, RI. Even
more damaging were the heavy surf and coastal flooding caused by the
tremendous seas and high tides caused by the long overwater fetch
length and duration of the storm. Waves 10 to 30 feet high were
common from North Carolina to Nova Scotia. High tides pushed to from
three to seven feet above normal. In New Jersey, the greatest tidal
departures of winter storms of record occurred during this event,
with tide heights exceeded only by the Great Atlantic Hurricane of
1944. In Delaware, Maryland, and Virginia, the highest water levels
were comparable to those of the nor'easter of March, 1962. A record
high tide of 7.8 feet occurred at Ocean City, MD on the 30th, which
eclipsed the old record of 7.5 feet recorded during the March 1962
storm. In Massachusetts, 25-foot waves reached the shoreline atop
high tides already 4 feet above normal. At Boston, the tide reached
14.1 feet above mean low water or about 1 foot less than the tides
associated with the "Blizzard of 1978." Elsewhere
treacherous swells, surf, and associated coastal flooding occurred
along portions of the Atlantic shoreline extending from Puerto Rico
and the Dominican Republic, to the Bahamas, along the U.S. and
Canada and in Bermuda.
Widespread
Extensive Damage
A state
by state damage summary reveals the widespread and extensive
damage caused by the storm and accompanying seas. Beach erosion and
coastal flooding was severe and widespread, even causing damage to
lighthouses. Hundreds of homes and businesses were either knocked
from their foundations or simply disappeared. Sea walls, boardwalks,
bulkheads, and piers were reduced to rubble over a wide area.
Numerous small boats were sunk at their berths and thousands of
lobster traps were destroyed. Flooding was extensive invading homes
and closing roads and airports. Former President Bush's home in
Kennebunkport, ME suffered damage as windows were blown out, water
flooded the building, and some structural damage also occurred. Even
inland areas suffered major damage. The Hudson, Hackensack, and
Passaic Rivers all experienced tidal flooding, and high winds
brought down utility poles, lines, tree limbs, and signs in several
states.
The
most extensive damage occurred in New England where federal disaster
areas were declared for seven counties in Massachusetts, five in
Maine, and one in New Hampshire. Off Staten Island, two men were
drowned when their boat capsized. Other fatalities occurred when a
man fishing from a bridge was either blown or swept off in New York
and a fisherman was swept off the rocks at Narrangansett, RI by
heavy surf. Offshore, six lives were lost when the Andrea Gail, a
swordfishing boat, sank. Total damage in the Halloween Storm, as it
came to be known because of its date, was in the hundreds of
millions of dollars.
Bizarre End to
the Halloween Storm
The southward
motion of the cyclone on October 31 had brought the storm over a
section of the Gulfstream with sea surface temperatures near 26
degrees C (80 degrees F). Convection began increasing in bands near
the center and it is estimated that subtropical characteristics were
acquired at 1800 UTC on October 31, setting the stage for a bizarre
ending to this storm (See Figure 3).
By 0600 UT on
November 1, central convection had increased to the point where a
tropical cyclone (estimated to be of tropical storm intensity) could
be identified within the central area of the low (See Figure 4).
Later it became a true hurricane in every sense of the word. Images
of the hurricane phase and a discussion as to why this storm will be
remembered in history as the "Unnamed
Hurricane" can be found in the Hurricane
Gallery of the Satellite's Eye Art Gallery.
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