Fire and Rain: The Legacy of Hurricane Lane in Hawaiʻi

Abstract

AbstractHurricane Lane (2018) was an impactful event for the Hawaiian Islands and provided a textbook example of the compounding hazards that can be produced from a single storm. Over a 4-day period, the island of Hawaiʻi received an island-wide average of 424 mm (17 in.) of rainfall, with a 4-day single-station maximum of 1,444 mm (57 in.), making Hurricane Lane the wettest tropical cyclone ever recorded in Hawaiʻi (based on all available quantitative records). Simultaneously, fires on the islands of nearby Maui and Oʻahu burned 1,043 ha (2,577 ac) and 162 ha (400 ac), respectively. Land-use characteristics and antecedent moisture conditions exacerbated fire hazard, and both fire and rain severity were influenced by the storm environment and local topographical features. Broadscale subsidence around the storm periphery and downslope winds resulted in dry and windy conditions conducive to fire, while in a different region of the same storm, preexisting convection, incredibly moist atmospheric conditions, and upslope flow brought intense, long-duration rainfall. The simultaneous occurrence of rain-driven flooding and landslides, high-intensity winds, and multiple fires complicated emergency response. The compounding nature of the hazards produced during the Hurricane Lane event highlights the need to improve anticipation of complex feedback mechanisms among climate- and weather-related phenomena.