Dora — 2023

A tropical wave that moved from Africa eventually crossed Central America and became Tropical Depression Five-E on 31 July 2023 about 250 nautical miles south of Manzanillo, Mexico. It strengthened to Tropical Storm Dora on 1 August and became a hurricane on 2 August. Dora underwent multiple episodes of rapid intensification, reaching major hurricane strength early on 3 August, and crossed from the eastern into the central Pacific on 6–8 August. The storm tracked generally westward at low latitude, passed about 500–600 n mi south of the Hawaiian Islands on 8 August, crossed the International Date Line on 12 August (becoming a typhoon in the western Pacific), and weakened to a remnant trough east of Japan by 17 August. Dora did not make any direct landfalls as a tropical cyclone. It remained well offshore of Mexico, the Hawaiian Islands, and other land areas throughout its life, with no coastal watches or warnings issued for Dora itself. The hurricane’s maximum estimated sustained winds peaked at 130 knots (150 mph) at 0000 UTC 6 August, with an estimated minimum central pressure of 939 mb; this corresponds to a high-end Category 4 on the Saffir–Simpson scale. In the central Pacific the best-track peak was about 125 kt (0000 UTC 10 August). There were no reported storm-surge observations or reports of significant rainfall from Dora itself at land stations in the eastern or central Pacific in the NHC report; no ship or buoy reported tropical-storm-force winds in those basins. The report does list environmental influences from the larger-scale pattern that produced very dry, gusty trade winds over portions of Maui and Hawai‘i Counties on 7–9 August. No direct deaths or direct property damage were attributed to Dora. However, the synoptic pattern associated with Dora—specifically a strong surface high to the north while Dora was well to the south—contributed indirectly to the extreme wind, dry, and downsloping conditions that helped drive the catastrophic wildfires on Maui on 8 August. Those fires caused 102 confirmed fatalities in Lahaina, Maui County, at least 32 injuries, destruction of more than 2,200 structures, over 2,100 acres burned, and an estimated $5.5 billion in damage. Noteworthy aspects include Dora’s small size and long lifespan crossing all three Pacific tropical cyclone basins; it was only the second hurricane on record to do so (after Hurricane John, 1994). Forecast track guidance and official NHC/CPHC track forecasts were generally skilled and had lower-than-average errors, while intensity forecasts were more challenged because Dora’s small size produced rapid and sometimes difficult-to-predict intensity changes.