NWS Support to South Carolina during Hurricanes Matthew, Irma, and Florence

The National Weather Service (NWS) provides Impact-Based Decision Support Services (IDSS) to a wide-range of core partners, such as emergency managers and public safety officials. The NWS works closely with these key decision-makers to ensure they have the most accurate, reliable and trustworthy weather, water and climate information by providing forecast advice and interpretative services.

The NWS Weather Forecast Office in Columbia, South Carolina has developed a deep relationship with the South Carolina Emergency Management Division (SCEMD) as the NWS state liaison office for South Carolina. During Hurricanes Matthew (2016) and Irma (2017), staff at NWS Columbia provided on-site IDSS at the South Carolina Emergency Operations Center (SEOC), briefing SCEMD, other state agencies and the Governor to support critical decisions involving evacuations and resource allocation.

Each hurricane provided its own unique challenge. Hurricane Matthew was the first hurricane to make landfall along the South Carolina coast since 2004, and resulted in extensive wind damage, significant freshwater flooding inland and storm surge flooding along the coast. Since the track was just off of the Florida east coast, minor deviations in track would have had a major influence in the expected impacts to South Carolina. Hurricane Irma was at one time forecast to be a major hurricane making landfall along/near the South Carolina coast. However, messaging had to be adjusted on the fly as the forecast track of Irma shifted westward to the west coast of Florida. Despite the shift westward, significant storm surge, wind and tornado impacts were still expected due to the size and strength of the hurricane.

The NWS Weather Forecast Offices serving the state of South Carolina developed tools and strategies to effectively coordinate messaging and serve the critical decision needs of state partners. One-pagers and an internal chat room on NWSChat were created as a means for each NWS office to collaborate significant impacts and key messages with those staff members deployed to the SEOC, the National Hurricane Center and FEMA Region IV. SCEMD and the NWS offices serving SC also coordinated to develop a scenario-based forecast using probabilities rather than presenting a large array of possibilities that were meteorologically viable. This allowed for better planning for possible impacts based on the most likely scenarios.

Through these efforts, the critical partnership between the NWS, SCEMD and other state agencies was strengthened. These shared experiences allowed the NWS to improve its service by adjusting decision support methods as needed to better meet the needs of a core partner at the time of a high impact event.