textproduct: Honolulu

SYNOPSIS

A band of showers currently over Oahu this morning will expand towards Maui County during the day today and over the Big Island on Saturday. Our moderate to locally breezy northeasterly trade winds will focus the showers over windward and mauka areas with brief downpours possible. A drier airmass will return over the western half of the state by Saturday afternoon, while showery conditions could persist over the windward areas of the eastern half of the state. Our north-northeast to northeast trade winds will strengthen this weekend and become locally strong by Saturday evening. Gusty winds are expected over leeward areas this weekend.

SHORT TERM UPDATE

Issued at 841 AM HST Fri Mar 27 2026

No changes were made. Previous forecast remains on track.

PREV DISCUSSION

Issued at 400 AM HST Fri Mar 27 2026

This mornings satellite imagery shows an increase of showers across the state especially over windward areas. 12Z Lihue and Hilo soundings show a strong inversion located at around 6000 to 7000 feet with precipitable water values of around an inch. While moisture values remain lower than normal, a gradual increase is expected today especially over Oahu and Maui County. Our north- northeast to northeast trade winds will also strengthen today into Saturday, which should increase orographic lift over windward mountain slopes and allow for some moderate showers. While heavy showers are not expected due to the strong trade wind inversion, brief downpours will be possible at times and we could see some showers anchoring along windward mountains through Saturday morning. A few inches of rain will be possible over the windward slopes during this time especially over the windward mountains of Maui County tonight.

On Saturday, a dying front will pass through parts of the state with a strong high building behind the front. A drier air mass with dewpoints down into the 50s will fill in behind the front over the western half of the state by Saturday afternoon. Our north-northeast to northeast trade winds will strengthen to locally strong speeds and will likely produce gusty winds across leeward areas through Sunday. Wind gusts of 40 mph will be possible with gusts up to 50 mph not out of the question. Depending on how strong the wind gusts become during the day Saturday, a Wind Advisory may be needed over select leeward areas for Saturday evening into Sunday. Meanwhile, moisture will likely linger over the eastern half of the state this weekend especially the Big Island. Some steady periods of light to moderate showers will be possible over windward Big Island especially Saturday through Sunday morning.

For the first half of next week, trade winds will gradually weaken to our more typical breezy speeds and shift more easterly as the high to our north drifts further east. A subtle increase of moisture will likely bring the return of scattered showers across the state primarily over windward and mauka areas.

AVIATION

Issued at 400 AM HST Fri Mar 27 2026

Light to moderate trade winds are expected to prevail across the islands, however a system to the northeast will push some moisture across the islands today, making for periodic windward showers and even some lee side showers at times today, mainly during the first half of the period. VFR is generally expected to prevail, however localized MVFR conditions are possible under showers.

AIRMET Tango remains in effect across the islands for moderate turbulence between FL270 and FL350. These conditions are expected to improve throughout the day today.

AIRMET Sierra is in effect for windward Kauai and Oahu due to shower activity. Conditions are expected to improve later today, however other islands may need to be considered for expansion depending on where moisture from the aforementioned system tracks.

MARINE

Issued at 400 AM HST Fri Mar 27 2026

A low pressure system northeast of the islands and a high pressure system to the far northwest of the Hawaii region will keep northeasterly trade winds in the forecast through early next week. Wind speeds for much of the coastal waters will be moderate to fresh this morning, though strong winds in the vicinity of Kauai have necessitated the issuance of a Small Craft Advisory (SCA) for the Leeward and Northwest Waters of Kauai, as well as the Kauai Channel. By this afternoon, a tightening pressure gradient across the islands is expected to spread Small Craft winds to the majority of the leeward waters and channels, with the exception of the Big Island. Winds are likely to increase to fresh to strong speeds and become more widespread by Saturday afternoon as a cold front sweeps southward across the islands. SCA criteria are likely to be sustained into early next week as high pressure builds to the north of the islands.

A small bump in surf is forecast today as another small medium- period northwest swell arrives. The bump in surf sustains through Saturday before gradually fading through the rest of the weekend.

For east facing shores, short-period wind wave energy from northeasterly trade winds will fade today, then build back in this weekend. A large short- to medium-period north-northeast (010-020 degrees) swell will build into the region Saturday night through Monday, likely bringing advisory-level surf to north- and east-facing shores late this weekend into early next week.

Along south-facing shores, small background pulses will keep surf heights above flat conditions through early next week.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 PM HST Saturday for Kauai Channel- Kauai Leeward Waters-Kauai Northwest Waters.

Small Craft Advisory from noon today to 6 PM HST Saturday for Alenuihaha Channel-Kaiwi Channel-Maalaea Bay-Maui County Leeward Waters-Oahu Leeward Waters-Pailolo Channel.