A high pressure system far northwest of the Hawaiian Islands will slowly drift from west to east over the next few days. This passing system will increase easterly trade winds into the moderate to breezy range lasting into the middle of next week. Brief pulses of enhanced showers are forecast with three passing easterly waves during this time period. Increasing shower trends will favor the windward mountain areas in the overnight to early morning hours starting Friday night and lingering into Tuesday morning. The strongest of these three waves will pass through the islands from late Sunday through late Monday.
A high pressure system far north of the Hawaiian Islands will drift slowly eastward over the next few days, increasing easterly trade wind speeds. An easterly wave riding into the islands on the easterly trade winds will bring increasing showers spreading from east to west across the islands from Friday afternoon near the Big Island into Saturday across the state. Periods of MVFR conditions and showers will develop over windward mountain areas.
AIRMET Sierra remains in effect for tempo mountain obscuration abv 020 for north and east sections of the Big Island.
AIRMET Tango is in effect for moderate low level turbulence downwind of island terrain.
Issued at 301 PM HST Thu Oct 15 2026
Surface high pressure far north of the islands will build as it shifts northeast of Hawaii through Saturday. As a result, trade winds will gradually increase to fresh to locally strong levels over the next couple of days. A Small Craft Advisory (SCA) is in effect for the typically windy waters around Big Island and Maui through Saturday and may need to be expanded in area as the high builds to the north. Elevated trade winds will persist into early next week.
The current small bump in the northwest swell will fade tonight before a moderate north-northwest swell arrives Friday. Surf along north and west-facing shores should top out near or slightly above seasonal average during the peak of the swell Friday afternoon and Saturday, then slowly decline late Saturday and Sunday as the dropping swell shifts more northerly and a smaller overlapping northwest swell arrives. Both swells will fade early next week.
A new long-periond south swell will gradually build this evening and may push surf along south-facing shores back above seasonal average into Friday. This swell will slowly decline Saturday through early next week.
Surf along east-facing shores will gradually increase tonight into Friday as trade winds strengthen over the region. Expect some wrap from the moderate north-northwest swell Friday afternoon into Saturday. This swell along with developing rough trade wind swell will produce east shore surf above seasonal average Saturday
Small Craft Advisory until 6 PM HST Saturday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
