textproduct: Honolulu

SYNOPSIS

Moisture will decrease through the weekend with light to moderate trades returning. Showers will impact windward and mauka locations, as well as leeward Big Island. A brief increase in showers expected Monday night on the Big Island before a return to relatively dry trades through the end of next week.

SHORT TERM UPDATE

Latest satellite and radar imagery shows that clouds and showers have persisted across the Kona side of the Big Island (along the coast of the North Kona, South Kona, and Kau Districts) in what has turned into an unusually cloudy and showery morning there. Essentially all hires and short term probabilistic guidance (HREF, REFS, HRRR- HI, FV3, ARW, NBM, etc.) suggests that these clouds and showers will stick around throughout the day today. Not anticipating anything particularly heavy or concerning, but based on observations and guidance, an update was pushed out this morning to increase shower chances and QPF for today along the leeward Big Island coast. Kauai is also likely to see some continued passing showers today, so short-term shower chances were trended upward there as well from the previous forecast.

Other than these updates in the short term, the rest of the forecast remains on track.

PREV DISCUSSION

Issued at 323 AM HST Sat Oct 10 2026

Currently at 3 AM HST, satellite and radar imagery showed scattered clouds and showers moving along mostly windward and mauka locations across the state.

The upper level low that brought rain to the area this week will weaken and move away to the northeast over the next few days. A surface high pressure system to our northeast will strengthen and bring easterly trades back to the region. Apart from a brief increase in moisture mainly for the Big Island Monday, the next several days will be dominated by relatively dry trades. Isolated to scattered showers windward and mauka will be most frequent at night. Otherwise, expect light to moderate winds and rather typical October conditions.

AVIATION

Light to moderate southeast winds will continue to bring showers to east and south facing coasts and slopes of Kauai for a few more hours this morning before moderate easterly trade winds fill in across the island chain later today. Showers are also persisting across the coastal areas and lower slopes of the Kona Districts of the Big Island, and are expected to impact PHKO for the next couple of hours. MVFR conditions are expected in and around these showers. Otherwise, VFR conditions are expected to prevail as drier air filters in on the trades.

AIRMET Sierra is in effect for mountain obscuration along the east and south facing coasts and slopes of Kauai, along with the stretch of lower slopes from South Point to Kailua-Kona on the Big Island this morning. This shower activity is expected to slowly taper off by the afternoon.

MARINE

Moderate to fresh trade winds will prevail this weekend, though weaker winds will remain in place over the western waters as a trough continues to linger west of the area. Trade winds then decrease this upcoming week into the light to moderate range through much of the week with slight day to day fluctuations. Strengthening trades are then possible towards the end of the week as high pressure builds north of the area.

The current moderate, long period south swell will fade gradually through the weekend, but a new long-period reinforcement is set to arrive on today, then peak Sunday into Monday. This will maintain elevated surf along south and west- facing shores, but it will remain below advisory levels. South shore surf will decline slightly by the middle of next week, but will be followed by a new long period swell Wednesday night or Thursday.

A medium-period northwest swell declines through the weekend as the source low pressure northwest of the Hawaiian Islands continues to weaken through Monday. This will cause small surf along north-facing shores to begin to fade today. A smaller long- period northwest swell is also forecast to move through the islands this weekend, which could prolong small surf through Sunday, but will fade by the beginning of next week. A small, long-period northwest swell is forecast to arrive on Monday and peak Tuesday, boosting north shore surf back to moderate levels.

Surf along east-facing shores will remain small as local winds remain fairly weak with only slight variations each day. Small, moderate-period west and east swells generated by multiple Pacific tropical cyclones are also moving through the islands this weekend.

FIRE WEATHER

Issued at 323 AM HST Sat Oct 10 2026

Light to moderate trades expected. Moisture will decrease Saturday night into Sunday, bringing RH values down to near dangerous fire conditions Monday on part of the Big Island, including near Kona. Inversion heights are around 5500-6500 feet.

HFO WATCHES/WARNINGS/ADVISORIES

None.