Messaging Extreme Winds associated with Major Hurricanes

Landfalling tropical cyclones pose considerable risk to many coastal communities. Associated hazards such as high winds, storm surge, flooding rain, and tornadoes can cause significant impacts upon societies. These impacts are accentuated during landfalling major hurricanes when core winds greater than 110 mph (177 km/h) devastate coastal communities, including those situated just inland before appreciable wind decay can be realized. Extreme hurricane winds can handicap affected populations and municipal infrastructures for months, if not years. Despite the improved accuracy in tropical cyclone forecasts, projecting the strike area for extreme winds remains difficult several days in advance, even though certain critical decisions for enhanced preparations may need to be made at that time range. Preparedness strategies for evacuations, relocations, and shelter options are often implemented according to tropical watches and warnings, but modulated knowing that the core winds could strike any place within the defined alert area. Modulation is exercised as the cyclone draws nearer and potential outcomes are narrowed. The remaining few hours before landfall is the time when confidence is highest and coincident with the last chance to protect lives against extreme hurricane winds. Using examples from Hurricane Andrew (1992) through Hurricane Matthew (2016), this presentation chronicles iterative improvements in messaging extreme winds to threatened populations, as well as circumstances in which messages can become shrouded or confused. Recommendations for continued improvement of threat/impact messaging to community decision-makers, along with the provision of safety instruction to the public, is also presented.