Sea breezes this morning will begin to transition back to trades and persist through the remainder of the week under a deep, upper-level ridge building well north of the islands. By Friday night, a weak, isolated frontal band will briefly enhance trade wind showers. Noticeably cooler and drier conditions will follow thereafter beginning this weekend.
Remnants of a front will linger just northwest of the Kauai producing little to no precipitation across the Garden Isle. sea breeze-drive winds continue today, producing only limited shower activity statewide. Latest ECMWF and GFS model guidance remain in strong agreement, showcasing a deep upper-level ridge building well north of the islands. An associated surface high is forecast to move over the islands midweek, signaling the transition back to a trade wind regime.
Trades will prevail through much of the outlook period, gradually strengthening throughout the week. These winds will play a key role in dispersing firework smoke from the highly anticipated New Year's Eve celebrations statewide.Overall, stability will dominate, with shower activity confined to windward and mauka areas. Toward the latter part of the week, guidance hints at a weak, isolated frontal band advancing southward across the islands, briefly enhancing trades and associated shower activity, predominately over windward and mauka locations, with potential for isolated showers spilling into leeward and interior areas.
Thereafter, a noticeably cooler and drier air mass in the wake of the aforementioned front will succumb the state, resulting in dewpoints falling into the upper-50s and lower-60s for most beginning this weekend. Needless to say, cooler and drier conditions are in the foreseeable future for the first few days of 2026.
Gentle east southeast winds will gradually strengthen to moderate to breezy speeds today and become more easterly. Expect mostly VFR conditions today with brief MVFR conditions occurring due to CLD and SHRA along exposed east and southeast slopes, as well a few sheltered leeward areas this afternoon where sea breezes will develop.
There are currently no AIRMETs in effect, but AIRMET Sierra for mountain obscurations could be possible over windward areas from Big Island to Oahu late tonight into early Tuesday morning with the upstream clouds and showers.
The remnants of a frontal boundary are located northwest of Kauai early this morning. This boundary will continue to weaken and drift to the west over the next couple of days. Moderate to fresh east to southeast winds will prevail over the area today, but a transition back to locally breezy trade winds will occur by midweek as high pressure builds back into the region.
A large, medium period northwest (330-340 degree) swell will arrive this morning and spread down the island chain today. Observations from offshore buoy 51001 show that wave heights reached over 12 feet yesterday evening, which was a bit above guidance. Based on these observations, the surf forecast for most north and west facing shores has been bumped up slightly from previous forecasts for today, and a High Surf Advisory (HSA) has been issued for north and west facing shores of Niihau, Kauai, Oahu, Molokai, and north facing shores of Maui. Additionally, an overlapping long period north-northwest swell will build tonight and will likely push surf to slightly higher HSA heights by Tuesday. Seas near 10 feet remain possible across exposed waters during the peak of the swell. This swell will gradually decline through the remainder of the week.
A slight increase in choppy east shore surf is expected tonight though mid-week as trade winds rebuild. Surf along south facing shores will remain tiny to small through the forecast period.
High Surf Advisory until 6 AM HST Wednesday for Niihau-Kauai Leeward-Waianae Coast-Oahu North Shore-Maui Windward West-Kauai North-Molokai Windward-Molokai North-Molokai West-Maui Central Valley North-Windward Haleakala.
