textproduct: Honolulu

SYNOPSIS

Drier air will move into the region today from west to east as the southern end of a cold front brings northeast trade winds back to the state. Breezy to strong trades will be with us through the coming week, along with the typical showers occurring mainly in windward and mauka regions.

UPDATE

Breezy to strong north-northeast to northeast trades will steadily fill in today into tonight from west to east across the state as a front pushes through. With abundant low level moisture ahead of the front and some marginal instability, we did increase the POPs for areas of Maui and the Big Island for this afternoon, especially windward areas. Some locally heavy showers will be possible this afternoon, capable of producing minor flooding. The 12Z HREF shows the heaviest precipitation over windward and southeast Big Island this afternoon, where a few inches of rain would be possible.

PREV DISCUSSION

Issued at 340 AM HST Sun Nov 1 2026 A significant area of strong and often persistent showers that moved over Kauai yesterday has diminished overnight. Flooding occurred on Kauai, including water over Kuhio Highway near Hanalei. As of 3:30 AM HST, radar shows an area of light to moderate showers mainly south of Oahu, with additional scattered showers extending from around Kona to near Upolu on the Big Island.

A weak front will bring drier air to the state today, moving in from west to east. The strongest part of the front will remain well north of the area, but a change to northeast trade winds will occur, and dewpoints will fall from the lower 70s in the mid 60s (at lower elevations). The Big Island will be the last island to experience the drier air, and showers will continue there into this afternoon. Additional light trade wind showers, mainly windward and mauka, will continue even after the drier air reaches the state.

A surface high will move east to a position around 500 miles to our north Monday and generally remain there through Wednesday. Later this week, this high will be replaced by a new high centered to our northwest moving in from the west, keeping the trades going. By this time, moisture will have increased somewhat, but not nearly as high as what we have experienced the past few days. Light trade wind showers will be with us, but heavy rain is not in the forecast.

Final note, some model runs show a tropical system forming to our southeast late this coming week. The models that do show this have the potential system moving west and staying to our south. NHC has a 50% chance of formation within 7 days. We will continue to watch for any increase in model consistency, and of course for guidance from NHC, through the coming days.

AVIATION

A weakening frontal boundary will push through the state today. Scattered light to moderate showers are embedded within the flow. Isolated locally heavy showers are possible as well, particularly over the eastern half of the state. Expect more frequent MVFR conditions statewide, with IFR conditions possible in heavier downpours. Winds will begin to strengthen today out of the NE, particularly in the wake of the front. Drier conditions are expected to settle in for most of the state tonight, with the exception being windward Big Island.

AIRMET Sierra is in effect for mountain obscurations across the state today. This AIRMET will be modified as the front passes and conditions potentially improve. However, lingering moisture may still allow mountain obscurations to occur after the front passes.

MARINE

A trough to the northwest of Kauai will sink southward across the island chain today and tonight, with high pressure to the north, behind the trough, causing fresh to strong northeast winds to overspread the region. A Small Craft Advisory (SCA) is in effect for all coastal waters as a result. Waves will also exceed 10 feet for exposed waters with the arrival of a north-northwest (330 degree) swell. This swell also brings high surf to north and west facing shores of Kauai and Oahu, as well as north facing shores of Maui and Molokai, for which a High Surf Advisory is in effect. Moderate to locally strong northeast trades are expected to continue through much of the week.

Surf along north facing shores will continue to build this morning well into High Surf Advisory levels as this swell peaks this afternoon into the evening hours before slowly declining Monday. However,advisory level surf is expected to linger through at least Monday morning before falling to more moderate levels by Monday evening. Another advisory level northwest swell is possible Thursday into Friday, and moderate to large surf action appears to continue into the weekend.

The current moderate, medium period south swell will hold today near seasonal average before declining on Monday. South shore surf will be tiny through much of the week with little southerly background energy reaching the islands. East-facing shores will see an increase in trade wind swell as northeast winds return today. Surf along east- facing shores will increase through Monday night and conditions will stay choppy as trades sustain through much of the week. A north- northeast trade wind swell (around 30 degrees) this week will reach moderate levels, but remains short-period, so the threat of harbor surges appears less likely.

FIRE WEATHER

Issued at 340 AM HST Sun Nov 1 2026 Recent wet weather has lowered fire concern due to wet fuels. Trades with drier air will move into the region today, and wind speeds will increase and remain elevated through at least Wednesday. The temperature inversion from Maui to the Big Island was around 9000 feet this morning and is expected to lower to around 7000 feet by Monday.

HFO WATCHES/WARNINGS/ADVISORIES

High Surf Advisory until 6 PM HST Monday for Kauai East-Kauai North-Kauai Southwest-Koolau Windward-Maui Central Valley North- Maui Windward West-Molokai North-Molokai Windward-Niihau-Oahu North Shore-Waianae Coast-Windward Haleakala.

Small Craft Advisory until 6 PM HST Monday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.