Hurricane Isabel

The 20th Anniversary

Satellite image of Hurricane Isabel approaching the coast of North Carolina as it was downgraded to a Category 2

Synopsis

Isabel became a tropical storm on September 6 and quickly strengthened as it tracked to the west-northwest (well north of Puerto Rico/Hispaniola). Isabel became a Category 5 Hurricane on September 11th and maintained that intensity for another day. It then turned to the northwest, taking a track directly toward the local area. Isabel made landfall on September 18th as a Category 2 Hurricane near Ocracoke Inlet in southeast North Carolina. It then crossed the North Carolina coastal plain as a hurricane before tracking across the Virginia Piedmont as a strong tropical storm. By midday on September 19th, Isabel weakened to a tropical depression as it tracked over western Pennsylvania. 

As is often the case with tropical systems in our part of the country, the wind field expanded well to the north of the center due to the gradient between strong high pressure over northern New England/Atlantic Canada to the north and Isabel to the south. As a result, sustained tropical storm force winds were observed over almost the entire Wakefield warning area. Given the strength of Isabel and the fact that our coastal zones were to the right of its track, the storm surge was the worst the area had seen since the 1933 Chesapeake-Potomac hurricane. In some cases, the storm surge on the main stem rivers exceeded the 1933 storm surge. Damage from storm surge was noted as far inland as Colonial Beach, West Point, Tappahannock, and Hopewell, where homes and many boats at local marinas were damaged or destroyed. See the hydrographs section below for detailed water level information from selected points.

Mandatory evacuations were ordered for parts of Currituck County and Hampton Roads. Eight fatalities were attributed to Hurricane Isabel in the NWS Wakefield county warning area. Over 2,000,000 customers of Dominion Virginia Power were without electricity, and local electricity cooperatives reported thousands of additional customers without power. The unusually large wind field uprooted thousands of trees, downed many power lines, damaged hundreds of houses, and snapped thousands of telephone poles. Hundreds of roads (including major highways) were blocked by fallen trees.

Isabel's Path

Zoom in to see the max wind speed and Saffir-Simpson Scale category for each point on the map

Isabel on Radar

The eye of Hurricane Isabel can be clearly seen making landfall just East of the Morehead City radar in North Carolina.

The gif shows the reflectivity and velocity data from the radar in Morehead City, NC of Hurricane Isabel as it made landfall just east of the radar

Radar imagery from Morehead City, NC (KMHX)- Reflectivity on the left, velocity on the right

As Isabel tracked further inland, the eye wall deteriorated and the storm weakened to a tropical storm over central Virginia. This can be seen from the radar in Wakefield, VA.

The gif shows reflectivity and velocity data from the KAKQ radar as Hurricane Isabel moves over northeast NC and through eastern and central VA

Radar imagery from Wakefield, VA (KAKQ)- Reflectivity on the left, velocity on the right

Surface Maps and Observations

12z (8am EDT) surface maps from September 16-19.

Max Wind Gusts

Tropical Storm force conditions were experienced across the forecast area.

Left: Max wind gusts (mph) measured on September 18th by observations sites; Right: Approximate wind speeds based on observations, damage, and reports from weather spotters. This map was created by NWS Wakefield in 2003.

Rainfall

The local area west of the Chesapeake Bay generally saw 3-6" of rain, while the Eastern Shore got 1-2". The Blue Ridge Mountains (located in LWX & RNK forecast areas) saw increased rainfall due to terrain enhancement.

Left: Storm Total Rainfall measurements from local observation sites; Right: Map of estimated Storm Total Rainfall across the Mid-Atlantic with Isabel's track overlaid

Hydrographs

Storm surge varied significantly across the region. At Sewell’s Point, VA, the maximum water level was 7.89 ft MLLW (which is 5 ft MHHW). Water levels of 5 ft MHHW were also seen at Cambridge (MD), Lancaster County (VA), and Mathews County (VA). At Gloucester Point, the water level reached 8.32 ft MLLW, which was 6.4 ft above MHHW. Even higher storm surge values were noted up the rivers in eastern Virginia. Storm surge values of around 9 feet were estimated at West Point, VA (up the York River). These levels were 1.5-2 ft higher than what occurred during the 1933 hurricane! A water mark at Crittenden, VA (in the northern part of Suffolk) was estimated to be 2.6-2.7 ft above the 1933 benchmark.  On the Albemarle Sound, storm surge values around 7 ft occurred at Edenton, with a surge of 5 feet observed on the Pasquotank River in Elizabeth City. Select hydrographs are shown below.

1

Cambridge, MD

2

Lewisetta VA

3

Wachapreague, VA

4

Kiptopeke VA

5

Sewell's Point, VA

6

Money Point, VA

7

Duck, NC

Images

The scope of the damage caused by Hurricane Isabel across North Carolina, Virginia, and Maryland cannot be accurately summarized by just a few pictures. Many homes were destroyed, roads were flooded, trees were knocked down, and much more. Here are just a few pictures of the aftermath.

From top left to bottom right: Damage along the Potomac River in Colonial Beach, VA; a flooded street in Crisfield, MD; an eroded shoreline in Gloucester County, VA; The Hampton Coliseum surrounded by flood water; multiple fallen trees block a roadway; boats tossed around at Jordan Point on the James River; a swath of trees blown down in Lewisetta, VA; a damage assessment map from Dominion Power

Takeaways

The Dangers of Generators and Carbon Monoxide

More homeowners than ever before owned a generator due to the equipment becoming more affordable and accessible. Considering some went without power for days to weeks, the increased accessibility of generators was a benefit for many. However, generators come with the danger of carbon monoxide poisoning if they are not placed in a well ventilated areas. Despite warning labels on the equipment and safety fliers distributed at the point of sale, carbon monoxide poisoning led to 3 fatalities in Virginia in the aftermath of Isabel. Since then, a "call to action" statement about the dangers of carbon monoxide has been developed for cases where extended power outages are possible.

Importance of the NOAA Weather Radio

The NOAA Weather Radio disseminates forecast information across the network 24/7. This becomes incredibly important during critical weather events, as it may be the only way for some to receive alerts. During Isabel, the Heathsville transmitter was compromised and unable to deliver updates about the storm. This left some residents feeling isolated and cut-off from important information. Since then, back-up power sources have been installed to reduce the chances losing signal. Also, a new transmitter will be added in New Kent, VA to increase signal coverage. The estimated installation date is in 2024.

Expansion of the Tide Gage Network

Storm surge along the Chesapeake Bay is a complicated thing to model and forecast due to the intricacies of the topography/bathymetry and the complex relationship between wind driven and astronomical tides. One problem that came to light during Isabel was the single tide gage in Dorchester County, MD that was located on the northern side of the county in Cambridge. It did not accurately measure the impact on the county due to its position. Since 2003, the tide gage network has been expanded. Twelve gages have been added, including a gage for southern Dorchester County in Bishop's Head. Tide forecasting has come a long way since 2003 and continues to improve, and the network continues to expand.

Current Forecasted Tide Gage Network in Eastern Virginia, Northeast North Carolina, and Lower Maryland Eastern Shore

*A tide gage in Duck, NC is used as reference for the Atlantic Coast in Northeast NC, but it is located just outside of NWS Wakefield's service area

Learn More

Credits

Information from this StoryMap was compiled from the Post-Storm Report (PSH) issued by NWS Wakefield in 2003, the Hurricane Isabel Service Assessment, and Tropical Cyclone Report from the NHC.

StoryMap Production

Allison Mitchell, Eswar Iyer

Radar imagery from Morehead City, NC (KMHX)- Reflectivity on the left, velocity on the right

Radar imagery from Wakefield, VA (KAKQ)- Reflectivity on the left, velocity on the right