Fig. 3: Ratio of USA hurricane strikes to basin-wide hurricane frequency.
From: Changes in Atlantic major hurricane frequency since the late-19th century
Ratio of the 15-year running count of United States of America (USA) strikes and 15-year running count of basin-wide frequency for hurricanes (a) and major hurricanes (b). Dotted gray line shows the values based on the recorded version 2 of the North Atlantic Hurricane Database (HURDAT2, ref. 33) frequency, while the thick solid line shows the value based on the HURDAT2 recorded USA strikes and the adjusted basin-wide frequencies; blue shading shows the 95% range on the ratio based on a Bootstrap sampling of the adjustment values. Gray background shading is as in Fig. 1, and highlights times where we have reduced confidence in the basin-wide and USA strike frequency estimates even after adjusting for likely missing storms.
