Light trade winds will produce rather dry conditions over most areas into tonight. Chances for heavy showers will increase during the day on Tuesday as developing low pressure and deep tropical moisture approach the islands from the southwest. The trough, or possibly a weak low, will pass over the island chain Tuesday night through Wednesday night, bringing the threat of heavy flooding rainfall and thunderstorms. The trough will weaken Thursday and Friday, though humid conditions with a chance of heavy showers may linger. Trade winds may briefly redevelop Saturday, followed by stronger northeast winds Sunday.
Issued at 345 PM HST Mon Oct 26 2026
A gentle trade wind pattern will continue this evening and become more light and variable tonight with localized land breezes developing across many areas. An area of moisture lingering around the Big Island will bring some showers throughout this evening with periods of MVFR conditions possible mainly over windward Big Island. Otherwise, VFR conditions should prevail through the night tonight.
A band of deep tropical moisture will arrive from the southwest Tuesday and will likely bring periods heavy rain and isolated thunderstorms. MVFR to IFR conditions should be expected at many areas across the state starting as early as Tuesday afternoon and persisting into Wednesday. The heaviest rain bands will likely arrive Tuesday night into Wednesday, where periods of LIFR conditions will be possible under the heavier rain bands.
No AIRMETs in effect, but we will need AIRMET SIERRA for mountain obscuration over majority of the state as the tropical moisture arrives.
AIRMET ZULU for moderate icing will also be possible at roughly between FL180 to FL270 on Tuesday.
This evening, a surface low remains nearly 800 nm northeast of the main Hawaiian Islands, while the remnants of Tropical Storm Olana are located a little over 1000 nm to the southwest. A trough, also to the southwest, is forecast to approach the offshore waters by late tonight and reach the local coastal waters on Tuesday. This feature will bring heavy showers with embedded thunderstorms over the next several days. Relatively weak prevailing wind flow will persist through the forecast period, except within any thunderstorms that develop.
The current medium to long period northwest swell that has elevated surf along north-facing shores today will continue to build and bring surf to near advisory levels along north and exposed west-facing shores Tuesday, then will gradually decline. An additional small north-northeast reinforcement should arrive by mid-week.
Overlapping south-southwest swells will keep surf along south-facing shores above average through Tuesday. A slightly larger south swell may bring an additional bump to the surf Thursday and Friday.
Surf along most east-facing shores will be small through the first half of the week, but areas exposed to wrapping northerly swells will experience periods of moderate surf. East-facing shores should also see a bump in surf if the north-northeast swell materializes during the latter half of this week.
Flood Watch from 6 AM HST Tuesday through late Wednesday night for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Central Oahu-East Honolulu-Ewa Plain-Haleakala Summit-Honolulu Metro- Kahoolawe-Kauai East-Kauai Mountains-Kauai North-Kauai South- Kauai Southwest-Kipahulu-Kohala-Kona-Koolau Leeward-Koolau Windward-Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward- Maui Central Valley North-Maui Central Valley South-Maui Leeward West-Maui Windward West-Molokai Leeward South-Molokai North- Molokai Southeast-Molokai West-Molokai Windward-Niihau-Oahu North Shore-Olomana-South Haleakala-South Maui/Upcountry-Waianae Coast-Waianae Mountains-Windward Haleakala.
Wind Advisory until 6 AM HST Tuesday for Big Island Summits.
