Still, Iselle emerged over the ocean on the west side of the island as a 50 mph tropical storm (see Figure 2). In fact, although interaction with the island and volcanoes played a role in weakening Iselle, increased wind shear as the storm neared landfall (28 to 35 mph from the northwest) probably contributed just as much to the storm's weakening. While Iselle's circulation was disrupted by its passage over Mauna Loa and Mauna Kea, the Central Pacific Hurricane Center (CPHC) continued tracking the storm afterward, which means that the volcanoes had not completely destroyed the storm. Iselle demonstrated, by way of both meteorological data and damage survey data, that this is not the case. Many people believe that Mauna Loa and Mauna Kea, two nearly 14,000-foot volcanoes on the Big Island, would completely destroy any tropical system that passes overhead. Myth 2: The Big Island's Volcanoes Break Up Storms The article notes that the center of the storm was in the vicinity of Maui, which is east of Oahu and Kauai. One key event was an 1871 storm that was dubbed "the Kohala Cyclone." While we do not have a track, footprint, or parameters for this event, we do have useful information from eyewitness reporters at the Hawaiian Gazette. To supplement this short “official” record, we collected information on earlier tropical cyclones by studying newspaper records and anecdotal evidence. Sixty-five years is not a long record, especially for Hawaii, which is not impacted by hurricanes often.
The official historical database of Central Pacific tropical cyclones maintained by the National Hurricane Center begins in 1949. Track and intensity of Hurricane Iniki (Source: AIR and NHC) Historical Evidence Oahu, Maui, or even the Big Island, are all equally viable targets. The steering current data indicate that sharp right turns in the flow-while not very common-do happen, but don't necessarily always steer storms to Kauai. If we look at Iniki's movement (Figure 1), for example, we can see that the hurricane was well south of Hawaii and moving westward when it made a sharp right turn to directly hit Kauai. Steering currents give us an idea of where storms were likely to have moved at any given time and are especially important for understanding tropical cyclone risk in the Central Pacific basin because of the low frequency of events that impact Hawaii. In fact, the AIR Tropical Cyclone Model for Hawaii assumes equal risk across the islands, a finding that was supported by two professors from the University of Hawaii who peer reviewed the model.įurther evidence that Kauai is not the only island at risk is presented below.ĪIR has analyzed steering currents from 1948–2010 in the North American Regional Reanalysis (NARR) data set. The strongest hurricanes tend to approach Hawaii from the south, given the profile of sea surface temperatures in the vicinity of the islands however, all the islands are at risk from storms approaching from that direction. Because the Hawaiian Islands are small targets in the Pacific and landfalls here are rare, these two storms are largely responsible for the long-held belief-the misconception-that Kauai is the only island at risk from tropical cyclones. Hurricane Iwa bypassed the island in November 1982, and in September 1992-just weeks after Hurricane Andrew hit Florida-Hurricane Iniki struck Kauai as a Category 4 storm, causing extensive damage across the island. The two most recent hurricanes to impact the state of Hawaii both hit the island of Kauai, the westernmost of Hawaii's main islands. In this article, we'll address two common myths about storms in Hawaii: One, they only hit the island of Kauai, and two, the Big Island's tall volcanoes destroy any storms that do pass, effectively protecting the other islands to the west. A subsequent AIR damage survey of the impacted areas revealed some property damage and numerous downed trees. Iselle had sustained winds of 60 mph at landfall, but less than a day before landfall, the storm was still at hurricane strength. It was the first tropical cyclone landfall on the Big Island since an unnamed storm arrived on its shores in 1958. On August 8, 2014, Tropical Storm Iselle made landfall on the Big Island of Hawaii's Kau Coast.