Hurricane Bertha, July 5-14, 1996. Service Assessment

摘要

Hurricane Bertha was an early season Category 2 storm when it made landfall on the coast of North Carolina on July 12, 1996. Twelve deaths have been directly attributed to Bertha with United States damages estimated at $270 million. Extensive evacuations of vulnerable areas occurred in advance of Bertha, including 250,000 in North Carolina, 80,000 in South Carolina and 20,000 in Georgia. Revenue losses to the tourist industry approached $40 million. Bertha closely paralleled the southeast U.S. coast at a distance from 170 to 200 miles. This created multiple state involvement with almost all of the U.S. east coast involved with some watch or warning. The NHCs track forecast was very accurate with average forecast track errors 15 percent lower than the 10-year official track averages. Where the storm came ashore in North Carolina, watches and warnings were posted 65 hours and 47 hours before landfall, respectively, which far exceeds the NHC stated goals of 36 and 24 hours. Nevertheless, the coordination between NHC and emergency managers, regarding the issuances of watches and warnings, was frustrated by efforts to reconcile the meteorology of the event with state and local response requirements. Berthas anticipated turn from a northwest direction to north-northwest as it approached the southeast coast was agonizingly slow. This put a great deal of pressure on the elected officials and Emergency Management Centers (EMCs) of Florida, South Carolina and North Carolina concerning what actions to take. This was also the first time the HLT had been fully deployed at the NHC. A Service Assessment Team was dispatched to the NHC as well as the impacted states to investigate these issues and to evaluate the HLT. Issues Berthas slow northward turn off the Florida coast caused the state of Florida to urge NHC to issue watches when NHC felt they were unnecessary. The major concern was that if the storm continued to move differently than forecast, sufficient response time would not be available if watches or warnings were issued at short notice. Similarly, South Carolina expressed the need for early release of the official forecast track before NHC had completed the internal NWS coordination process. Several recommendations have been made in this report to help resolve these issues.