textproduct: Honolulu

SYNOPSIS

Breezy trades become moderate late this week through the weekend. Scattered showers focus windward and mauka into next week.

SHORT TERM UPDATE

No amendments have been made to the current forecast as it remains on track. Broad area of high pressure remains anchored north of the islands, maintaining breezy trades across the islands, bringing periods of showers to windward and mauka locations. Model guidance continues to show an upper-level low and associated trough moving into the vicinity of the islands from the west, which is expected to gradually disrupt the trade wind pattern through the weekend and into the early part of next week.

PREV DISCUSSION

Issued at 318 PM HST Wed May 27 2026 High stability remains firmly entrenched over the state. Breezy trades are delivering showers to windward and mauka sections of the islands this morning beneath the resident 8kft trade inversion. No change in the large scale pattern is anticipated for the next several days as the islands reside under or equatorward of the subtropical jet placing the region beneath a broad swath of large scale subsidence in maintenance of existing stability. Sensible weather will be largely modulated by periodic fluctuations in the trades which will weaken in concert with periodic height falls across the Central/North Pacific. The first such instance will be a gradual weakening of trades during the latter half of this week in response to a rapidly weakening 1040mb high migrating toward 35N and weakening considerably as it does so. It is certainly plausible that trades are briefly lost altogether early next week setting the stage for a period of land/sea breezes. Given the high stability environment in place, would expect little in the way of interior showers should that pattern develop. Otherwise, scattered showers will focus windward and mauka for the balance of the forecast period.

AVIATION

Trades will continue to gradually trend downward over the course of the week as a stable weather pattern remains in place over the islands. Isolated showers cannot be ruled out for windward sites, however VFR conditions are widely anticipated.

AIRMET Sierra remains in effect for mountain obscuration over Kauai, however conditions are gradually improving this evening, so this may be cancelled by or even before next issuance.

AIRMET Tango remains in effect across all islands down mountain for moderate turbulence due to breezy trades, however as winds scale back in intensity, its possible that this AIRMET may be scaled back or even discontinued within the next 24-48 hours.

MARINE

Issued at 318 PM HST Wed May 27 2026 A surface ridge north of the state will maintain breezy to strong trade winds across the Hawaiian coastal waters through this afternoon before a weakness developing in the ridge allows trade wind speeds to ease slightly during the latter part of the week into the weekend. With the ASCAT pass from earlier today showing wind speeds already starting weaken, the Small Craft Advisory has been scaled back to the typically windier waters around the Big Island and Maui County. A more significant weakening of the trade winds is likely this weekend into early next week as a large North Pacific low pressure system far north of the islands breaks the ridge down even further.

A small, long-period northwest swell is peaking as it fills in down the island chain this afternoon. North- and west-facing shores are experiencing near- to above-seasonal-average surf that will hold through the evening before gradually subsiding into the weekend.

A series of medium-period south swells will continue to bring small surf to south facing shores through Thursday. A more significant long-period south swell is expected to begin filling in Thursday night and will likely bring above-advisory-level surf to south-facing shores through the weekend. This swell originated from a storm-force low that passed south and east of New Zealand over the weekend, generating seas of 35 to 40 feet or greater within Hawaiis swell window, though the peak of the energy may pass just east of the state. The buoys near American Samoa picked up a portion of this swell today, seeming to peak around 5 feet 16 seconds, with the peak of the swell also likely passing to their east. Elevated surf along south-facing shores will likely continue into the first week of June due to a continued active weather pattern near New Zealand sending swells toward Hawaii.

Rough surf along east-facing shores will gradually lower Thursday through the weekend as trade winds ease.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 PM HST Thursday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.