textproduct: Honolulu

SYNOPSIS

A ridge of high pressure will remain anchored in place north of the Hawaiian Islands for the foreseeable future. Easterly trade winds will continue to blow across the region through the end of this week. Shower activity will remain limited with brief increasing trends on Tuesday, and stronger trends from Thursday through Friday as a weak easterly wave moves from east to west across the state. Any showers will that develop in this trade wind pattern will favor windward mountain slopes of each island during the overnight to early morning hours.

SHORT TERM UPDATE

Forecast looks on track for this morning. No anticipated update.

PREV DISCUSSION

Issued at 303 AM HST Sun Jul 5 2026 The satellite imagery this morning shows a weak easterly wave near 150W longitude riding the easterly trade winds towards the Big Island. This weak trough will bring a brief period of increasing shower trends to the state on Tuesday. Another stronger trough currently near 130W longitude, associated with the remnants of former tropical cyclone Douglas, will ride the trade winds into Hawaii from Thursday to Friday producing another round of showers spreading east to west across the state. Rainfall amounts with this first system will be limited due to the stable ridge aloft, the second trough will bring significant increases to humidity levels and the potential for higher rainfall amounts favoring island mountain slopes.

Otherwise, easterly trade winds will continue through the end of this week as the subtropical ridge remains locked in place north of Hawaii. Subtle day to day changes to the trade wind speeds should be expected. Mostly stable weather conditions are forecast for the next seven days with slight increases in shower activity on Tuesday, and stronger rainfall trends from Thursday through Friday as two easterly waves drift through the island chain. Rainfall amounts over the next seven days will remain limited due to large scale stability, with the highest amounts forecast during the Thursday to Friday time period.

AVIATION

Issued at 303 AM HST Sun Jul 5 2026 Moderate to locally breezy trades will continue through the holiday weekend, with a slight uptick in speed expected this afternoon. Low clouds and showers may continue to impact windward and mountain areas at times throughout the period, with some spillover showers into leeward sites possible as well, however VFR conditions are broadly expected, with localized MVFR possible mainly for windward sites.

AIRMET Tango remains in effect for moderate low level turbulence over and downwind of terrain for all islands. This AIRMET will likely continue through the weekend.

MARINE

Issued at 303 AM HST Sun Jul 5 2026 A high pressure ridge north of the Hawaiian Islands will remain nearly stationary this week and help drive moderate to strong trades across the local waters. A Small Craft Advisory (SCA), currently in effect for the typical windy waters and channels around Maui and the Big Island will be expanded by mid morning to cover all local Hawaiian waters. Moderate to locally strong trades and accompanying SCAs will continue through the week.

A new long period south-southwest swell, already being reported at the near shore buoys, will continue to fill in today. This will boost south shore surf heights to just shy of High Surf Advisory (HSA) levels through Monday. If this swell comes in much above guidance, a HSA will need to be issued. This swell will remain the primary south swell during the rest of next week as it gradually fades beginning on Tuesday.

Surf along east facing shores will remain rough and choppy through the forecast period as moderate to locally strong trades hold. Surf along north facing shores remains flat to tiny through much of this week.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 PM HST Monday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.