textproduct: Honolulu

SYNOPSIS

A strong high will build north of the state while remnants of Fausto continues to weaken and shifts far northwest. Breezy easterly trades will strengthen to locally windy levels Friday afternoon and evening then hold into Saturday. A drier and more stable airmass will also settle in over the state that could produce very windy downsloping winds that may warrant a Wind Advisory. Trades will ease back to the usual breezy levels Sunday into early next week as the high weakens. Typical summertime showers are expected for windward and mountain areas.

SHORT TERM UPDATE

This evening's IR satellite imagery loop shows unorganized layered clouds with isolated embedded convection, associated with the remnants of former TC Fausto, several hundred miles northwest of the Hawaiian islands. Closer to state, scattered low level clouds, caught up in the trades, can be seen drifting towards windward locations. Shower activity since noon generally produced only a few hundredths of an inch of rain at select windward locations. The outlier was a gauge just northwest of Waimea, on the Big Island, where a third of an inch of rain was reported. Hi- res models show more of the same tonight with isolated to scattered showers pushing up against the windward slopes in moderate to locally breezy trade flow. In the evening update, the chance of precipitation was lowed slightly for the south Kona slopes on the Big Island, but cloud cover was increased to account for current trends. Otherwise, the rest of the forecast appeared on track.

PREV DISCUSSION

Issued at 347 PM HST Thu Jul 30 2026

A surface high far north of the state is driving breezy easterly trade winds across the state. Satellite and radar show scattered clouds with limited light showers mainly along windward and mauka areas, with minimal rainfall statewide this afternoon. The high will strengthen tonight through Friday as remnant low Fausto weakens far northwest of the state. Expect an increase in clouds and showers mainly along windward and mauka tonight as a low level deck of clouds and showers moves from east to west.

Breezy to locally windy trades are expected Friday afternoon into Saturday under a dry and stable airmass that will lower inversion heights to around 5,000 ft. Under these conditions winds could be accelerated downslope, near mountain tops and ridges, through gaps in the terrain, and in areas typically exposed to the trade winds that may warrant a wind advisory. However, uncertainty remains between the high resolution model guidance running a little stronger and earlier than the global models. With the drier airmass, dewpoints are expected to dip below 70 degrees, offering relief from the recently hot and muggy conditions.

Trades will weaken to moderate to locally breezy levels Sunday into early next week as Hurricane Genevieve tracks far northeast of the state, disrupting the trade wind flow. Another round of hot, muggy conditions could develop by the mid-week as remnant moisture from Genevieve moves over the state.

AVIATION

Moderate to breezy trade wind weather will prevail through the period. Occasional MVFR ceilings and lowered visibilities over windward and mauka areas may occur within brief, heavier showers.

No AIRMETs are currently in effect. Friday's lower level trades may strengthen enough to warrant an AIRMET TANGO across and immediately S through W of high terrain.

MARINE

Trades strengthen into Friday in support of the current Small Craft Advisory (SCA). Further expansion of the SCA may be warranted as strong trades become established this weekend.

The current medium period S swell will fade through the weekend. A mix of small south swells over the next few days will maintain surf along S facing shores slightly below the seasonal average.

An E swell will arrive tonight and persist through the weekend. This swell is a combination of the short period trade wind swell and the medium to long period east swell generated by Hurricane Genevieve in the East Pacific. N shores will see flat to tiny surf through early next week.

FIRE WEATHER

Issued at 347 PM HST Thu Jul 30 2026

Breezy trades will continue to strengthen to locally windy levels across the state by Friday afternoon and evening. A drier and more stable airmass will drop inversion heights to around 5,000 ft Friday afternoon into Saturday that could further accelerate winds downslope, along mountain tops and ridges and through gaps in the terrain. With the low inversion heights, chances of precipitation will be low and limited to windward areas. While KBDI will remain below the critical thresholds this hot, dry and windy pattern could make for some near critical fire weather concerns, especially for areas above the inversion height and in the windier areas. Trades are expected to return to more normal moderate to locally breezy levels Sunday into early next week.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory from 4 AM Friday to 6 AM HST Saturday for Big Island Windward Waters-Kaiwi Channel-Maui County Leeward Waters-Maui County Windward Waters.

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