High pressure far north of the Hawaiian islands will begin to weaken, allowing winds to decrease to moderate levels for the remainder of the week. Passing showers will be carried in on the trade wind flow over the next several days, with an increase in shower activity this weekend.
Vfr. Moderate trades will hang in through Wednesday morning and then gradually weaken through the day. Widely scattered showers with only brief MVFR conditions possible within more organized showers.
AIRMET Tango is in effect for tempo moderate turbulence downwind of terrain below flight level 090.
Issued at 332 PM HST Tue Oct 20 2026
High pressure far north of Hawaii will maintain fresh to strong trade winds through tonight, and a Small Craft Advisory (SCA) remains in effect for all waters except windward Big Island through tonight. Trades will steadily decrease early Wednesday as the high weakens and is displaced eastward by an approaching low far northwest of the islands. The SCA will likely be trimmed back to the typically windy waters around Big Island and Maui at that time. Trade winds will lower to gentle strength, or may become disrupted entirely, as the low passes to the north Thursday and Friday. Trades could then turn more northeasterly this weekend. By next week, model discrepancies exist regarding a low pressure system moving in from the southwest which could affect wind speeds and direction.
Small surf for north facing shores is expected through tomorrow before a small northwest swell arrives giving a small bump Thursday afternoon and Friday. This will then be followed by a slightly larger mid period north- northwest swell this weekend. A potential storm force low in the process of developing north of Japan could send a larger long period west- northwest swell early next week. This swell is still uncertain and will depend on the evolution of the developing low.
Small background south swells will keep relatively small surf for south facing shores through much of the week. A moderate south- southwest swell is expected this weekend, and could bring surf heights above seasonal averages.
Rough trade wind swell will gradually decline later tomorrow morning as trade winds decrease, leading to smaller surf through the remainder of the week. A small medium period east swell is possible Thursday into the weekend.
Small Craft Advisory until 6 AM HST Wednesday for most Hawaiian coastal waters and channels.
