Officials on Maui planned to sound warning sirens, alerting residents to shelter in place or take refuge at one of seven shelters around the island.
A Hurricane Warning is in effect for O'ahu, Kaua'i County (including the islands of Kaua'i and Ni'ihau), and Maui County (including the islands of Maui, Lana'i, Moloka'i, and Kaho'olawe).
US President Donald Trump issued an emergency warning for Hawaii due to the storm, designating federal aid in addition to state and local respondents.
A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 18 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case within the next 36 to 48 hours. Maui and the Big Island are also under tropical storm warnings.
SURF: Large swells generated by Douglas will affect the Hawaiian Islands tonight, producing life-threatening and potentially damaging surf along exposed shores.
STORM SURGE: The combination of higher than predicted water levels, risky storm surge, and large breaking waves will raise water levels by as much as 3 feet above normal tides near the center of Douglas.
Maui is being pelted by heavy rain with strong wind gusts, and forecasters expect Kauai to see the worst of the storm Sunday night, The Associated Press reports. Total rain accumulations of 3 to 6 inches with locally higher amounts are possible, with the greatest rainfall in elevated terrain.
Since Douglas is a fairly small tropical cyclone, small shifts in its track or intensity fluctuations can mean major differences for the islands in its projected path. Haleakala on Maui rises to over 10,000 feet while the volcanic mountains of Mauna Kea and Mauna Loa rise to over 13,000 feet on Hawaii's Big Island. The Island of Hawaii was spared, but the storm will have an imminent impact on Maui, Oahu, and overnight on the Island of Kauai. There is little change in the forecast track, which passes just north of the Big Island shortly after sunrise, and Maui later this morning, then near or moving over the rest of the main Hawaiian Islands through the rest of today and tonight.
Hurricane Douglas did not weaken as expected.
Latest forecast cone on Hurricane Douglas. Due to the steep terrain of the islands, localized strong wind gusts are expected.
Forecast rainfall as Douglas passes Hawaii.
The mid-level ridge will continue to drive Douglas toward the west-northwest, with the current motion vector estimated to be 285/14 kt.
Douglas gained some strength as it spun past Hawaii and headed west-northwest into the Pacific Ocean at 20 miles per hour, the Central Pacific Hurricane Center said in its 2 p.m. Monday report.
Rounding the base of a large high pressure area to its north, Douglas is moving quickly toward Hawaii.