Marine Weather and Tide Forecast for Kahaluu-Keauhou, HI

DISCUSSION

Currently at 3am HST, radar and satellite show cloudy skies with windward and mauka showers occurring across the island chain. A few isolated showers are making it over to leeward areas. Most of these showers are on the lighter side. Showers should continue riding on the trades through the next several days mostly overnight into the early morning hours.

A low pressure to the northeast is meandering off the southern portion of the West Coast, with a high pressure and mid-level ridging to our north. A subtropical jet is anchored just to the south of the islands and will remain in place at least through Friday. As such, expect trades to continue through at least Thursday afternoon. Showers riding on the trades should be confined to windward and mauka locations through this time frame.
Thursday evening and into the weekend with the jet moving to the east and a closed off low overhead expect and increase in showers with some leeward spots getting in on the action.

Looking into early next week the low overheard begins to move northeastward while ridging begins to build back in place for the first half of next week. A few shortwaves riding around a potent low over Alaska could bring some unsettled weather to the islands.
Its too far out to begin to talk about anything impactful as both deterministic and probabilistic guidance shows disagreement in location and strength.

AVIATION

Satellite imagery this morning shows a large band of clouds riding towards the eastern slopes of the Big Island on the trade winds. Expect periods of MVFR conditions over the next few hours for the windward Big Island slopes lasting into the afternoon.
Brief showers remains in the forecast for all islands.

AIRMET Sierra remains in effect for mountain obscuration along north and east slopes of the Big Island.

AIRMET Tango remains in effect for low level moderate turb over and S thru W of island mountains.

MARINE

A surface ridge will remain northeast of the state through the week and continue to bring fresh to locally strong trade winds to all local waters. A Small Craft Advisory (SCA) for the typical windy waters surrounding Maui and the Big Island has been extended through Wednesday evening. The SCA may need to be extended through late week as fresh to locally strong winds persist.

The current moderate period south-southwest swell will slowly decline today into Wednesday. By Thursday, only small background south swell will exist.

Surf along east-facing shores will be rough and choppy the next several days due to the fresh to locally strong trades. A series of small northwest swells will keep small surf in place along north facing shores today with no significant swells in the horizon.

HFO WATCHES/WARNINGS/ADVISORIES
Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters.