HURRICANE ISABEL

Hurricane Isabel Improving Emergency Response Plans



Hurricane Isabel Improving Emergency Response Plan

Introduction

Hurricane Isabel is described as a storm that hits once in a century. The impact of it caused was devastating. Hurricane Isabel made landfall in the Outer Banks of North Carolina at 18 September 2003 as a category 2 hurricane (Lawrence et al. 2005). It was directly responsible for 17 fatalities, of which 10 were due to drowning, and 7 were due to falling trees. The storm caused widespread property damage from riverside flooding, storm surge flooding, and wind. The economic losses exceeded $3.3 billion, and approximately 6 million customers affected by power outages (NOAA 2004) (Bailey, 1975).

Isabel produced heavy rainfall and flooding in the central Appalachian mountain region along the track of the storm. Interaction of the tropical cyclone circulation with the intricate terrain of the central Appalachians played an important role in flooding from Isabel and, in the flood hydrology of the central Appalachians (Sturdevant-Rees et al. 2001; Atallah and Bosart 2003; Hart and Evans 2001; Villarmi and Smith 2010). Extreme short-term rainfall rates from outer rain bands are important flood agents in urban watersheds of the eastern United States (Bailey et al. 1975) (Bailey, 1975).

Wind damage from Hurricane Isabel extended far inland from the point of landfall. Damages were largely due to falling trees and power outages in the major urban areas of the mid-Atlantic (NOAA 2004). Wind damage attributed partially to the wet antecedent soil moisture during the period preceding the storm and drought conditions in preceding seasons, which weakened the tree stock (NOAA 2004). Wind damage not restricted to the region close to the track of the storm, but also associated with secondary wind maxima in hurricane rain bands. Wind damage is an important component of the multiple hazards of tropical cyclones in the northeastern United States.

Isabel produced record wave and surge conditions near the Outer Banks of North Carolina. A significant wave height of 8.1 m, a record for 27 yr of monitoring, was measured by the U.S. Army's Field Research Facility at a wave rider buoy in 20 m of water [U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center]. Storm surges were 2-2.5 m above normal tide levels near the point of landfall along the Atlantic coast of North Carolina and 1-2 m in the North Carolina estuaries of the Pamlico and Albemarle Sounds (Lawrence et al. 2005). The surge and waves created a new inlet, unofficially named Isabel Inlet, by washing out a portion of Halteras Island between Halteras and Frisco; the inlet destroyed a portion of North Carolina Highway 12 and all utility connections to Halteras Village (NOAA 2004) (Colle, 2008).

Extensive storm surge flooding also occurred in Chesapeake Bay and the associated estuaries of the Potomac and James Rivers. Isabel was the worst hurricane to affect the Chesapeake Bay region since 1 933; storm surges of 2-2.5 m above normal levels occurred in the upper Chesapeake Bay (Lawrence et ...