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| Mid-Atlantic Hurricanes: A Closer Examination (2010) |
Welcome to Mid-Atlantic Hurricanes: A Closer Examination. This is a monthly
column based on the book, Hurricanes and the Middle Atlantic States. It examines
tropical cyclones from a historical Mid-Atlantic perspective.
column based on the book, Hurricanes and the Middle Atlantic States. It examines
tropical cyclones from a historical Mid-Atlantic perspective.
and Virginia coastline from November 11 to 14. Gales, rainfall of 5 to 10 inches, and erosive,
flooding, surf will be remembered in that area. In fact, the entire Mid-Atlantic shore, as well as
some interior sections, took a modest beating.
The storm, a marriage of tropical energy and non-tropical elements, provided a late surprise
to what had been a remarkably quiet hurricane season. And it suggests the possibility of a
stormier future. Indeed, from December 18-20 sections of the Mid-Atlantic region were
slammed by an epic nor'easter, a memorable snowstorm.
The following are historical notes on Ida or, more accurately, "nor'Ida":
- Rainfall in North Carolina, Virginia, Maryland and Delaware was the heaviest from a
tropical cyclone-related weather system this late in the year since the passage of
Hurricane Kate through southeastern North Carolina on November 22, 1985.
- Nor'Ida provided the most significant Mid-Atlantic coastal flooding from a tropical
cyclone or related weather system since the passage of Hurricane Isabel in September
2003.
- The combination of wind, rain and flooding in tidal sections of the Mid-Atlantic
region was the most severe from a tropical cyclone or related weather system since the
passage of a tropical storm through eastern North Carolina and off the Virginia coast on
December 2-3, 1925. (However, the remnants of Hurricane Ida had little to compare to
as very few tropical weather systems have affected the region after the first week of
November.)
The weather drama off the Mid-Atlantic coast likely concludes the 2009 hurricane season.
Once again, no hurricane made landfall along the East Coast. The current lull in this traditional
part of the hurricane belt isn't likely to continue much longer. Consider the following:
The last hurricane to make landfall on the Eastern Seaboard north of Florida was Gaston in
2004. More than 75 tropical cyclones have formed in the North Atlantic basin since then,
including an incredible 28 in 2005. Meanwhile...
A total of 10 hurricanes struck the Gulf Coast from 2004 to 2008. Two tropical storms, Ida
and Claudette, came ashore in 2009.
Fran in 1996 was the last major hurricane (Saffir-Simpson Category 3 or higher) to slam
the East Coast north of Florida. Hurricane Hugo in 1989 was the last Category 4 to strike the
area. No known Category 5 has visited the coastline from Georgia to Maine. During active
hurricane cycles, major hurricanes typically arrive in this section about two or three times each
decade.
Even powerful nor'easters have been rare. Nor'Ida might indicate a change. For much of
the Mid-Atlantic coast, it was the most destructive nor'easter since February 1998. Yet, by
historical standards, it wasn't close to the worst.
Coastal communities would do well to repair beach erosion, particularly any losses to
protective dunes. They may soon face additional assaults from Mother Nature.
Hurricane Ida May Signal A Stormy Change |
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The Saffir-Simpson Hurricane Scale is a 1 to 5 rating based on a hurricane's present
intensity. This is used to give an estimate of the potential property damage and flooding
expected from a hurricane landfall.
Wind is the determining factor in the scale as storm surge values are highly dependent on
the slope of the continental shelf and the shape of the coastline in the landfall region. Note
that all winds are using the U.S. one-minute average.
Wind damage in the Mid-Atlantic region will likely be more severe than those described by
the conventional scale. (The described wind effects in the Middle Atlantic region -- contained
in parentheses and rated through Category 2 -- are based on hurricane history and the
author's observations and opinion. Category 2 is the highest known hurricane-related wind
speed to affect the Middle Atlantic states, from Virginia on north, other than in isolated
locations.)
Category One Hurricane:
Winds 74-95 mph (64-82 kt ). No significant damage to building structures. Damage
primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly
constructed signs.
(Considerable damage to awnings, windows, shingles and chimneys. Moderate roof
damage to total loss for some homes. Widespread uprooting of trees. Many tree-shaded
streets made impassable. In the countryside: many fences flattened, weaker outbuildings and
barns severely damaged or loss, much crop loss. Large-scale power outages throughout
urban and rural areas. Numerous boats damaged or destroyed at anchorage.)
Category Two Hurricane:
Winds 96-110 mph (83-95 kt). Some roofing material, door, and window damage of
buildings. Considerable damage to shrubbery and trees, with some trees blown down.
Considerable damage to mobile homes, poorly constructed signs, and piers.
(Widespread damage to windows, chimneys and shingles. Many roofs damaged or carried
away. Scattered serious structural losses, with some flawed or weaker buildings blown down.
Catastrophic loss of trees. Most tree-shaded streets impassable. Many power lines and signs
blown down. In the countryside: fences, barns, weaker outbuildings flattened; severe crop
damage. Power outages lasting several days and longer throughout urban and rural areas.
Most boats damaged or destroyed at anchorage in highest wind areas.)
Category Three Hurricane:
Winds 111-130 mph (96-113 kt ). Some structural damage to small residences and utility
buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with
foliage blown off trees and large trees blown down. Mobile homes and poorly constructed
signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival
of the center of the hurricane. Flooding near the coast destroys smaller structures with larger
structures damaged by battering from floating debris. Terrain continuously lower than 5 ft.
above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying
residences with several blocks of the shoreline may be required. Hurricanes Jeanne and Ivan
of 2004 were Category 3 hurricanes when they made landfall in Florida and in Alabama,
respectively.
Category Four Hurricane:
Winds 131-155 mph (114-135 kt ). More extensive curtainwall failures with some complete
roof structure failures on small residences. Shrubs, trees, and all signs are blown down.
Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying
escape routes may be cut by rising water 3-5 hours before arrival of the center of the
hurricane. Major damage to lower floors of structures near the shore.Terrain lower than 10 ft.
above sea level may be flooded requiring massive evacuation of residential areas as far
inland as 6 miles (10 km). Hurricane Charley of 2004 was a Category 4 hurricane that made
landfall in Charlotte County, Florida, with winds of 150 mph.
Category Five Hurricane
Winds greater than 155 mph (135 kt). Complete roof failure on many residences and
industrial buildings. Some complete building failures with small utility buildings blown over or
away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe
and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5
hours before arrival of the center of the hurricane. Major damage to lower floors of all
structures located less than 15 feet above sea level and within 500 yards of the shoreline.
Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the
shoreline may be required. Only three Category 5 hurricanes have made landfall in the United
States since records began: The Labor Day Hurricane of 1935, Hurricane Camille (1969), and
Hurricane Andrew in August 1992. The 1935 Labor Day Hurricane struck the Florida Keys
with a minimum pressure of 892 mb--the lowest pressure ever observed in the United States.
Hurricane Camille struck the Mississippi Gulf Coast causing a 25-foot storm surge, which
inundated Pass Christian.
| The Saffir-Simpson Hurricane Scale (with suggested revisions by Rick Schwartz) |
| To learn more, order Hurricanes and the Middle Atlantic States. Send a check or money order for $25.95, postpaid. (Internet special-- The regular price is $32.95.) Virginia residents add $1.00 sales tax. Make checks payable to Blue Diamond Books. Mail to: 6516 China Grove Ct., Alexandria, VA 22310 Or pay by credit card through the convenience of PayPal (see Home Page). |