textproduct: Honolulu

SYNOPSIS

Breezy trades will continue through Monday, bringing limited showers mainly windward and mauka. An upper level low will help weaken winds and turn them out of the south Wednesday. Chances of showers will increase as moisture increases with the potential for heavy rain across Hawaii.

SHORT TERM UPDATE

An area of scattered low level clouds with embedded light to briefly moderate showers is currently filling in along windward and mauka slopes of Maui County and the Big Island. Isolated clouds with embedded light showers can been seen elsewhere across windward and mauka areas of Kauai and Oahu. Rainfall totals for windward Maui County and the Big Island have been rather minimal with some gauges reporting less than 0.15 inches for the past 3 hours. This trend will continue through the night with showers expected to decrease by late Monday morning and afternoon. Breezy northeast trades will hold through Monday. Remainder of forecast remains on track and unchanged.

PREV DISCUSSION

Issued at 341 PM HST Sun Oct 4 2026 High pressure north of Hawaii and a weak disturbance passing to the south will result in breezy trade winds and stable weather through Monday. Scattered low clouds and isolated showers will move through the trade wind flow and primarily impact windward slopes, but rainfall accumulations will remain light.

Winds will weaken and veer southeasterly by late Tuesday, and south by Wednesday, as a sharp trough approaches from the northwest. A surface low will form along the trough and southerly winds will draw deep tropical moisture over the islands, while a cold pool aloft associated with the upper low will act to destabilize the atmosphere over the state. PW values will increase to around 2 inches and dewpoints will rise to around 70 Thursday and into the lower 70s Friday. As this deeper moisture moves in, heavy rain will become likely. The timing and location of the moisture is depicted slightly different in the long range models, but at this time it appears all the islands will be impacted at some point. Thus, not getting too specific in the forecast details for now, but expect an overall wetter pattern and southerly winds from around late Wednesday through at least Friday, and possibly lingering into next weekend.

AVIATION

Moderate trades will continue into Tuesday with isolated showers across windward and mountain areas where short-lived MVFR conditions are possible. Otherwise, VFR conditions will prevail across the state through Monday.

AIRMET Tango continues for moderate turbulence downwind of mountain terrain. No other AIRMETs are in effect.

MARINE

High pressure north of the Hawaiian Islands will maintain fresh to locally strong trade winds through Monday. The Small Craft Advisory for the windier waters and channels around Maui County and the Big Island remains in effect through Monday afternoon. Thereafter, high pressure to the north weakens and trades will start to diminish. Troughing developing northwest of the islands will likely cause winds to veer out of the southeast around midweek and bring increased shower activity for the latter half of the week.

A new small, long-period south swell will slowly fill in tonight and Monday, with a peak slightly above average Tuesday into Wednesday. Near or slightly below average surf will hold through the rest of the week, maintained by a mix of new, small south swells.

A small, medium-period northwest swell will arrive tonight and peak Monday, producing a small bump in surf through Tuesday. Surf will continue to trend up for north shores as a slightly larger long-period northwest swell peaks Wednesday. Surf may approach moderate levels late in the week as a medium-period northwest swell further increases. Surf along east-facing shores will be elevated and choppy through Monday due to the locally strong trades.

A small, long-period west swell originating from Typhoon Choi-wan is forecast to reach the islands Thursday into the weekend, which may produce moderate surf for west-facing shores of the Big Island.

FIRE WEATHER

Issued at 341 PM HST Sun Oct 4 2026 Breezy trades will continue into Tuesday with RH values just above the critical threshold for fire weather each afternoon through Tuesday. Fire weather risk then diminishes through the remainder of the week as moisture increases, winds decrease, and showers increase in coverage. The inversion should range from 6 kft to 8 kft through Monday.

HFO WATCHES/WARNINGS/ADVISORIES

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