Lane (2018)

A tropical depression formed from a tropical wave on 15 August 2018 about 935 nautical miles southwest of the southern tip of the Baja California Peninsula. The system strengthened to Tropical Storm Lane the same day and moved generally west to west‑northwest across the eastern and central Pacific. Lane rapidly intensified beginning late on 16 August, became a hurricane on 17 August, and reached major hurricane strength the next day. It remained a major hurricane for about six days as it crossed into the central Pacific, then weakened as it approached the Hawaiian Islands, became a tropical storm by 25 August, and degenerated to a remnant low that dissipated by 29 August.

Lane did not make a direct landfall on the main Hawaiian Islands. Its closest approach to the state was within about 120–130 nautical miles of most islands on 24–25 August. The storm passed near the islands while at hurricane strength earlier in its life, but when it neared Hawaii the system had weakened to a tropical storm and then a tropical depression; there were no recorded hurricane‑strength landfalls on the main islands.

The hurricane’s peak estimated intensity was 140 knots (about 161 mph) with a minimum central pressure of 926 millibars at 0600 UTC 22 August, making it a Category 5 on the Saffir‑Simpson scale at peak. That peak occurred while Lane was in the central Pacific and made Lane only the fifth Category 5 on record in the central Pacific basin. Peak wind estimates were based on multiple aircraft measurements (flight‑level winds, SFMR surface winds, and dropwindsondes) and carry some uncertainty due to differing instrument values.

Although Lane did not strike the islands directly, it produced extreme rainfall and some storm surge and high tides. The heaviest rain fell on the Island of Hawaii, where the Kahuna Falls station recorded 58.00 inches of rain — a new Hawai‘i state record for tropical cyclone storm total rainfall and the second highest tropical cyclone total in U.S. records after Hurricane Harvey. Other totals on Hawaii Island included many sites exceeding 25–48 inches (for example, Mountain View 52.82 in, Waiakea Uka 49.48 in, Saddle Road Quarry 48.52 in). Kauai and Oahu saw localized storm totals over 9 inches in some places, and one Kauai site measured more than 36 inches. A NOAA buoy (51002) in Lane’s path reported sustained winds to 72 kt and gusts to 93 kt before being damaged. Reported storm tide and surge measurements were relatively modest onshore compared with the rainfall impacts; localized coastal flooding and high tides occurred but the report emphasizes rainfall and freshwater flooding as the primary hazard.

Lane caused one direct death in Hawaii: on 28 August a man drowned after entering a rain‑swollen stream on Kauai. The Island of Hawaii experienced the most severe flooding and damage: more than 100 structures were affected and public infrastructure damage was at least $20 million. Maui suffered infrastructure damage estimated initially above $2 million, and western Maui experienced three wildfires on 23 August that burned about 2,000 acres, destroyed 21 homes, and caused over $4 million in reported damage; the fires were fanned by gusty winds while parts of western Maui were in moderate drought.

Noteworthy aspects include Lane’s long duration as a major hurricane and its peak Category 5 intensity in the central Pacific — a rare occurrence — and that it was the most aircraft‑reconnoitered central Pacific tropical cyclone in history. Forecasts and warnings generally performed well: NHC track forecasts were better than average and intensity forecasts were strong at short range, though forecasters did not anticipate a brief re‑intensification in the central Pacific. The storm set the Hawai‘i tropical cyclone rainfall record and produced unusual, record‑breaking flooding on the Big Island.