Hurricane Isabel

Hurricane Isabel was a large and powerful Category 5 Atlantic hurricane that struck the east coast of the United States in September 2003. The ninth named storm, fifth hurricane, and second major hurricane of the season, Isabel formed in the eastern Atlantic Ocean on September 6 from a tropical wave. It moved northwestward through an area with light wind shear and warm waters, resulting in strengthening. Isabel reached peak winds of on September 11. After fluctuating in intensity for four days, Isabel gradually weakened and made landfall on the Outer Banks of North Carolina, with winds of on September 18, or a Category 2 on the Saffir-Simpson scale. Isabel quickly weakened over land and became extratropical over western Pennsylvania on the next day. On September 20, the extratropical remnants of Isabel were absorbed into another system over Eastern Canada.

In North Carolina, the storm surge from Isabel washed out a portion of Hatteras Island to form what was unofficially known as Isabel Inlet. Damage was greatest along the Outer Banks, where thousands of homes were damaged or even destroyed. The worst of the effects of Isabel occurred in Virginia, especially in the Hampton Roads area and along the shores of rivers as far west and north as Richmond and Baltimore. Virginia reported the most deaths and damage from the hurricane. About 64% of the damage and 69% of the deaths occurred in North Carolina and Virginia. Electric service was disrupted in areas of Virginia for several days, some more rural areas were without electricity for weeks, and local flooding caused thousands of dollars in damage.

Moderate to severe damage extended up the Atlantic coastline and as far inland as West Virginia. Roughly six million people were left without electric service in the eastern United States from the strong winds of Isabel. Rainfall from the storm extended from South Carolina to Maine, and westward to Michigan. Throughout the path of Isabel, damage totaled about $3.6 billion (2003 USD). 16 deaths in seven U.S. states were directly related to the hurricane, with 35 deaths in six states and one Canadian province indirectly related to the hurricane.

Meteorological history

A tropical wave moved off the western coast of Africa on September 1, and continued westward. The system gradually became better organized, and Dvorak classifications began early on September 5. Based on the development of a closed surface circulation, it is estimated the system developed into Tropical Depression Thirteen early on September 6. Hours later, it intensified into Tropical Storm Isabel, Located within an area of light wind shear and warm waters, Isabel gradually organized as curved bands developed around a circular area of deep convection near the center. It steadily strengthened as it moved to the west-northwest, developing a large ragged eye located near the deepest convection. On September 7, Isabel strengthened into a hurricane, the fifth hurricane of the season.

The eye, overall convective pattern, and outflow steadily improved in organization, and deep convection quickly surrounded the -wide eye. Isabel intensified on September 8 to reach major hurricane status, or Category 3 status, while located east-northeast of Barbuda; this made it the second major hurricane of the season. As a result, Isabel weakened slightly to a Category 3 hurricane. The hurricane turned more to the west due to the influence of the Bermuda-Azores High. The hurricane continued to intensify, and Isabel reached its peak intensity of and a minimum central pressure of 915 mbar (hPa; 27.02 inHg) on September 11, a Category 5 hurricane on the Saffir–Simpson Hurricane Scale. As Isabel underwent another eyewall replacement cycle, outflow degraded in appearance and convection around the eye weakened. Early on September 13, Isabel weakened to a strong Category 4 hurricane. and late on September 13, Isabel re-attained Category 5 status. During this time, Isabel attained annular characteristics, becoming highly symmetrical in shape and sporting a wide eye. A NOAA Hurricane Hunter Reconnaissance Aircraft flying into the hurricane launched a dropsonde which measured an instantaneous wind speed of , the strongest instantaneous wind speed recorded in an Atlantic hurricane. Cloud tops warmed again shortly thereafter, and Isabel weakened to a strong Category 4 hurricane early on September 14. Later that day, it re-organized, and for the third time, Isabel attained Category 5 status while located north of San Juan, Puerto Rico. By that time, the track had shifted more to the west-northwest. Increasing vertical wind shear contributed in weakening the hurricane further, and Isabel weakened to a Category 2 hurricane on September 16, while located southeast of Cape Hatteras, North Carolina. and Isabel remained a Category 2 hurricane for two days, until it made landfall between Cape Lookout and Ocracoke Island on September 18, with winds of . Isabel was a large hurricane at landfall, with a windfield of . The system weakened after it made landfall, though due to its fast forward motion, Isabel remained a hurricane until it reached western Virginia, early on September 19. After passing through West Virginia as a tropical storm, Isabel became extratropical over Western Pennsylvania, near Pittsburgh. The system continued turned northward, and crossed Lake Erie into Canada. Early on September 20, the extratropical remnant of Isabel was absorbed by a larger extratropical storm, over the Cochrane District of Ontario. Officials declared mandatory evacuations for 24 counties in North Carolina, Virginia, and Maryland. Roughly half of the Outer Banks left. Hundreds of thousands of people, while more than 12,000 people stayed in emergency shelters.

19 major airports along the East Coast of the United States were closed, with more than 1,500 flights canceled. The Washington Metro and Metrobus system closed prior to the arrival of the storm, and Amtrak canceled nearly all trains south of the nation's capital. Schools and businesses throughout its path closed prior to Isabel's arrival to allow time to prepare; hardware and home improvement stores reported brisk business of plywood, flashlights, batteries, and portable generators, as residents prepared for the storm's potential impact. The federal government was closed excluding emergency staff members.

A contingency plan was established at the Tomb of the Unknowns at Arlington National Cemetery that, should the winds exceed , the guards could take positions in the trophy room (above the Tomb Plaza and providing continual sight of the Tomb) but the plan was never implemented. However, it spawned an urban legend that the Third Infantry sent orders to seek shelter, orders that were deliberately disobeyed.

Delaware governor Ruth Ann Minner activated the state National Guard. The Cape May-Lewes Ferry closed for several days in anticipation of the storm. Many residents prepared their houses by boarding windows and purchasing emergency supplies. The Sussex County chapter of the American Red Cross advised local high schools to be on stand-by as potential shelters in the event evacuation occurred. Emergency coordinators in several counties were on alert, though none issued evacuations. In preparation for anticipated power outages, the Jersey Central Power and Light company arranged to receive more electrical crews from its parent company, FirstEnergy. Several flights in and out of the state were delayed or canceled, and the Cape May-Lewes Ferry canceled travel across the Delaware Bay during the duration of Isabel. In Atlantic City, casino workers prepared for coastal flooding by placing sandbags at boardwalk entrances. FEMA mobilized and dispatched an Urban Search and Rescue Task Force of 28 people to the state for possible rescue duty. Days before the storm made landfall, the Salvation Army prepared food and aid for potentially affected citizens.

The threat of the hurricane canceled some flights in and out Pennsylvania. To compensate, Delta Air Lines allowed those flying to or from Philadelphia, Allentown, and Harrisburg to reschedule to a later date. American Airlines offered a similar option. United Airlines and United Express opted to waive charging fees for travelers in and out of the state. The Pennsylvania Emergency Management Agency activated a support team to assist Urban Search and Rescue operations as part of the threat from the storm. The state's National Guard placed 2,990 guardsmen on Emergency Condition 5 status to be deployed anywhere in the state for emergency support, with other guardsmen readying equipment such as generators, heavy trucks, water trailers, and engineer equipment for deployment. State police officers were readied for deployment, while the state health department contacted hospitals to ensure generators were in working condition. The state Environmental Protection Agency prepared for the storm by monitoring the status of all dams, water treatment facilities, and nuclear plants. In addition, the Pennsylvania Turnpike Commission stationed extra workers to patrol the highways in poor drainage areas, with extra equipment prepared for quick response for potential road blockage. Prior to the arrival of the storm, officials from PECO Energy prepared its largest workforce in its history with 1,500 workers, including employees from Commonwealth Edison in Illinois and Detroit Edison.

In New York, Governor George Pataki urged residents to purchase emergency supplies and to fill cars with gasoline. The State Emergency Management Office began preparing for the hurricane about a week before it moved ashore. The office also issued a Level 1 emergency activation, with a planning unit readying contingency plans and in coordinating the efforts of other state offices. The state's National Guard began preliminary preparations for possible support efforts by reviewing the list of personnel able to be mobilized in the event of an emergency. Army and Air National Guard officials identified needed equipment in the event of an emergency, such as helicopters, generators, high-axle vehicles, and communications equipment. State police officers established contingency plans for personnel and equipment to assist as needed. The State Office of Parks, Recreation and Historic Preservation ensured needed equipment were operational, and also secured buildings with sandbags to prevent flooding.

On September 18, the Canadian Hurricane Centre issued heavy rainfall and wind warnings for portions of southern Ontario. A gale warning was also issued for Lake Ontario, eastern Lake Erie, the Saint Lawrence River and Georgian Bay. A news report on September 14 warned conditions could be similar to the disaster caused by Hurricane Hazel 49 years prior, resulting in widespread media coverage on the hurricane. Researchers on a Convair 580 flight studied the structure of Isabel transitioning into an extratropical storm, after two similar studies for Hurricane Michael in 2000 and Tropical Storm Karen in 2001. While flying in a thunderstorm, ice accumulation forced the plane to descend.

Impact

{|class="wikitable" style="float:right;margin:0 0 0.5em 1em"

|+Deaths and damage by region

!rowspan=2|Region

!colspan=2|Deaths

!rowspan=2|Damage<br />(2003 USD)

! Direct||Indirect

| Florida||1||0||0

| North Carolina||1||2||$450 million

| Virginia||10||22||>$1.85 billion

| West Virginia||0||0||$20 million

| Washington, D.C.||0||1||$125 million

| Maryland||1||6||$820 million

| Delaware||0||0||$40 million

| Pennsylvania||0||2||$160 million

| New Jersey||2||1||$50 million

| New York||1||0||$90 million

| Rhode Island||1||0||0

| Ontario||0||1||Unknown

! Total||17||35||$3.6 billion

Strong winds from Isabel extended from North Carolina to New England and westward to West Virginia. The winds, combined with previous rainfall which moistened the soil, downed many trees and power lines across its path, leaving about 6 million electricity customers without power at some point. Parts of coastal Virginia, especially in the Hampton Roads and Northeast North Carolina areas, were without electricity for almost a month. Coastal areas suffered from waves and its powerful storm surge, with areas in eastern North Carolina and southeast Virginia reporting severe damage from both winds and the storm surge. Throughout its path, Isabel resulted in $5.5 billion in damage (2003 USD) and 51 deaths, of which 17 were directly related to the storm's effects. The governors of Pennsylvania, West Virginia, Maryland, New Jersey, and Delaware declared states of emergency.

Caribbean and Southeast United States

thumb|left|Rainfall totals from Hurricane Isabel|alt=Map showing the total rainfall from Hurricane Isabel from September 17–21, 2003. Orange colors, found in Ohio, Pennsylvania, and Delaware, represent lighter rainfall amounts while the red, purple, and blue colors, found primarily in North Carolina and Virginia, represent higher rainfall amounts.

Powerful surf affected the northern coastlines of the islands in the Greater Antilles. Strong swells also lashed the Bahamas. During most hurricanes, the location of the Bahamas prevents powerful swells of Atlantic hurricanes from striking southeast Florida. However, the combination of the location, forward speed, and strength of Isabel produced strong swells through the Providence Channel onto a narrow stretch of the southeastern Florida coastline; wave heights peaked at at Delray Beach. In the northern portion of the state, waves reached up to in height at Flagler Beach, causing the Flagler Beach Pier to be closed due to damaged boards from the waves. Rip currents from Isabel killed a surfer at an unguarded beach in Nassau County, with an additional six people requiring rescue from the currents.

In northeastern South Carolina, the outer rainbands produced moderate winds reaching at Myrtle Beach. Rainfall was light, peaking at in Loris.

North Carolina

Isabel produced moderate to heavy damage across eastern North Carolina, totaling $450 million (2003 USD). The storm surge produced a wide inlet on Hatteras Island, unofficially known as Isabel Inlet, isolating Hatteras by road for two months. Strong winds downed hundreds of trees of across the state, leaving up to 700,000 residents without power. Most areas with power outages had power restored within a few days.

Mid-Atlantic

About 1.24 million people lost power throughout Maryland and Washington, D.C. The worst of Isabel's effects came from its storm surge, which inundated areas along the coast and resulted in severe beach erosion. In Eastern Maryland, hundreds of buildings were damaged by the storm surge and related tidal flooding. The most severe flooding occurred in the southern portions of Dorchester and Somerset counties and on Kent Island in Queen Anne's County. Thousands of houses were affected in Central Maryland, with severe storm surge flooding reported in Baltimore and Annapolis. Washington, D.C. sustained moderate damage, primarily from the winds. Throughout Maryland and Washington, damage totaled about $945 million (2003 USD), with only one direct fatality due to flooding.

The effects of the hurricane in Delaware were compounded by flooding caused by the remnants of Tropical Storm Henri days before. Winds reached in Lewes. leaving at least 15,300 without power. Along the coast, the storm surge reached at Reedy Point. High tides and waves caused beach erosion and coastal flooding, which closed 62 roads statewide, inundating a portion of Delaware Route 1.

thumb|Hurricane Isabel's extratropical remnant over the [[Northeastern United States on September 19|alt=Satellite image of Hurricane Isabel's remnants located over the Northeasten United States on September 19]]

The passage of Isabel through Pennsylvania resulted in two deaths and about $160 million in damage. The other death occurred when a tree struck a motorist in Lancaster. Wind gusts reached in Forks Township, and in Philadelphia. The winds knocked down trees and power lines, leaving 1.4 million customers across the state without power. Dozens of trees and houses were also damaged by the fallen trees, and roads were closed.

Although well to the east of Isabel's center, New Jersey experienced gale-force winds, with gusts to recorded in Cape May. The hurricane killed two people in the state. A tree struck and killed a motorist in Independence Township, and high waves killed a swimmer off Wildwood Crest. In North Jersey, the high winds caused three injuries, one due to a fallen tree, and the others due to broken glass. In Union County, storm debris forced the cancelation of schools.

In New York, one person drowned while surfing off Long Beach. Statewide, the hurricane left at least $45 million in damage. The hurricane brought unusual birds to the western portion of the state, including petrels and shearwaters normally found in salt-water regions or over the open ocean. Most of the birds died within a few days due to the sudden change in habitat. In Cayuga County, downed power lines lit one building on fire.

Virginia

thumb|Flood waters at [[Langley AFB, Hampton, Virginia as a result of Hurricane Isabel|alt=Photo of flooded roadways at Langley AFB in Hampton, Virginia, due to Isabel.]]

The storm surge assailed much of southeastern Virginia causing the worst flooding seen in the area since the 1933 Chesapeake–Potomac hurricane, peaking at an estimated in Richmond along the James River. The surge caused significant damage to homes along river ways, The strong storm surge surpassed the floodgate to the Midtown Tunnel while workers attempted to close the gate; about of water flooded the tunnel entirely in just 40 minutes, with the workers barely able to escape. The damage to the electrical grid and flooding kept Old Dominion University, Norfolk State University, Virginia Commonwealth University, University of Richmond, The College of William & Mary and many of the region's other major educational institutions closed for almost a week. Further inland, heavy rainfall was reported, peaking at in Sherando, Virginia, damage in the state totaled over $1.85 billion (2003 USD), among the costliest tropical cyclones in Virginia history. In Vermont, wind gusts reached in Starksboro. The winds knocked down a few trees and power lines, some of which fell onto vehicles.

Isabel dropped light to moderate precipitation across the eastern half of Ohio, with isolated locations reporting over .

Swells from Isabel produced moderate surf along the Atlantic coast of Nova Scotia, particularly in the Gulf of Maine. The strong pressure gradient between Isabel and a high pressure system over eastern Canada produced strong easterly winds across lakes Ontario and Erie. and gusts reached as strong as at Port Colborne, Ontario. By about four months after the passage of the hurricane, disaster aid totaled about $516 million (2004 USD), primarily in North Carolina and Virginia. Over 166,000 residents applied for individual assistance, with about $117 million (2004 USD) approved for residents to assist with temporary housing and home repairs. About 50,000 business owners applied for Small Business Administration loans, with about $178 million (2004 USD) approved for the assistance loans. About 40,000 people visited local disaster recovery centers, designed to provide additional information regarding the aftermath of the hurricane.

In North Carolina, hundreds of residents were stranded in Hatteras following the formation of Isabel Inlet. People who were not residents were not allowed to be on the Outer Banks for two weeks after the hurricane due to damaged road conditions. When visitors were allowed to return, many ventured to see the new inlet, despite a 1-mile (1.6-km) walk from the nearest road. Dredging operations began on October 17, about a month after the hurricane struck. The United States Geological Survey used sand from the ferry channel to the southwest of Hatteras Island, a choice made to minimize the impact to submerged aquatic vegetation and due to the channel being filled somewhat during the hurricane. On November 22, about two months after the hurricane struck, North Carolina Highway 12 and Hatteras Island were reopened to public access. On the same day, the ferry between Hatteras and Ocracoke was reopened. with 85% restored by two nights. with all outages restored by a week after the hurricane. Allegheny Power restored power to about 20% of its customers by two days after the storm. Power workers throughout Canada assisted the severely affected power companies from Maryland to North Carolina. Hydro-Québec sent 25 teams to the New York City area to assist in power outages. Officials in Connecticut sent a tractor trailer truck with water and ice to help residents in North Carolina.

In the Chesapeake Bay, the passage of the hurricane caused an algal bloom of phytoplankton, which was the largest bloom in the fall ever observed in the body of water. By two weeks after Isabel, the water returned to normal levels. The hurricane also disrupted the flight pattern of several bird species, leading to unusual birds being spotted across upstate New York and Vermont.

Retirement

Because of widespread property damage and extensive death toll, the World Meteorological Organization retired the name Isabel in the spring of 2004, and it will never again be used for a North Atlantic tropical cyclone. It was replaced with Ida for the 2009 season.

References

External links

National Hurricane Center advisory archive for Hurricane Isabel
National Weather Service Assessment
Category 5 Hurricane Isabel eye vortices java loop, Interpretation of
Hurricane Isabel in Perspective: Proceedings of a Conference