Hilo

Tonight: Partly cloudy. Isolated showers after midnight. Lows 60 to 68 near the shore to 49 to 55 at 4000 feet. Light winds becoming west up to 10 mph after midnight. Chance of rain 20 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 77 to 82 near the shore to 64 to 70 at 4000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy with scattered showers. Lows 60 to 68 near the shore to 50 to 56 at 4000 feet. Light winds. Chance of rain 40 percent.

Kona

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 70 near the shore to 44 to 50 near 5000 feet. Light winds. Chance of rain 20 percent.

Saturday: Mostly sunny. Isolated showers in the afternoon. Highs around 84 near the shore to around 68 near 5000 feet. Northwest winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Mostly clear. Lows around 70 near the shore to 44 to 51 near 5000 feet. Light winds.

Waimea

Tonight: Partly cloudy. Lows 60 to 69 near the shore to 51 to 59 near 3000 feet. East winds up to 10 mph in the evening becoming light.

Saturday: Mostly sunny with isolated showers. Highs around 78 near the shore to 68 to 77 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Isolated showers in the evening. Lows 60 to 69 near the shore to 52 to 59 near 3000 feet. Light winds becoming east up to 10 mph after midnight. Chance of rain 20 percent.

Kohala

Tonight: Partly cloudy. Lows 60 to 69 near the shore to 51 to 59 near 3000 feet. East winds up to 10 mph in the evening becoming light.

Saturday: Mostly sunny with isolated showers. Highs around 78 near the shore to 68 to 77 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Isolated showers in the evening. Lows 60 to 69 near the shore to 52 to 59 near 3000 feet. Light winds becoming east up to 10 mph after midnight. Chance of rain 20 percent.

South Big Island

Tonight: Partly cloudy. Lows around 71 near the shore to around 49 near 5000 feet. Northeast winds up to 15 mph.

Saturday: Sunny. Isolated showers in the afternoon. Highs around 84 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Saturday Night: Mostly clear. Lows around 72 near the shore to around 50 near 5000 feet. Light winds becoming northeast around 10 mph after midnight.

Puna

Tonight: Partly cloudy. Isolated showers after midnight. Lows 60 to 68 near the shore to 49 to 55 at 4000 feet. Light winds becoming west up to 10 mph after midnight. Chance of rain 20 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 77 to 82 near the shore to 64 to 70 at 4000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy with scattered showers. Lows 60 to 68 near the shore to 50 to 56 at 4000 feet. Light winds. Chance of rain 40 percent.

Waikoloa

Tonight: Mostly clear. Lows around 70 near the shore to 47 to 52 above 4000 feet. Light winds becoming southeast up to 10 mph after midnight.

Saturday: Sunny. Highs 81 to 86 near the shore to 64 to 71 above 4000 feet. Northwest winds up to 10 mph.

Saturday Night: Mostly clear. Lows 68 to 73 near the shore to 47 to 53 above 4000 feet. Light winds.

Detailed Forecast

Synopsis

Showers will remain focused over the western half of the state in the vicinity of a surface trough through tonight. Light to moderate easterly trades will return for the weekend with showers generally favoring windward and mauka areas. Next week, pockets of moisture will move into windward and mauka areas on the strengthening trades as high pressure strengthens to the north.

Discussion

The weak front that stalled over Oahu this morning has dissipated, leaving a surface trough between Oahu and Kauai this afternoon. While overall shower activity has declined since this morning, current radar and satellite imagery show a broad band of low clouds with isolated to scattered showers mostly across the western end of the state, in the vicinity of the trough.
Light to locally moderate easterly trade winds will fill in across the state tonight into tomorrow and persist through the weekend. Winds will likely remain light enough across the state to allow for localized sea breeze activity tomorrow afternoon. This hybrid pattern with redeveloping trades and potential sea breeze activity will allow for isolated to scattered showers to favor windward and mauka areas overnight with isolated showers possible over island interiors in the afternoon. With winds gradually strengthening on Sunday, sea breeze development may be hindered, but cannot rule out a few sea breezes in the more sheltered areas.
Another cold front will approach from the northwest this weekend. Models continue to show its tail end dissipating before it reaches the state, but remnant moisture will move in on the strengthening trades early next week as high pressure strengthens to the north. These breezy to strong trades will persist through the week and into next weekend. As pockets of moisture ride in on the trades, periodic showers will focus primarily over windward and mauka areas.

Aviation

This afternoon, a broad band of low clouds and showers continues to linger over the western end of the state in the vicinity of a stalled trough. Showers have been trending down throughout the day, although a few areas of MVFR ceilings and visibilities remain possible within showers over Kauai and Oahu.
As the trough weakens and lifts back northward tonight through early Saturday, shower activity over the western end of the state will decrease. Elsewhere, mostly dry, VFR conditions will prevail from Maui County to the Big Island throughout the next 24 hours. Winds will also be on a downward trend through Saturday, which will allow local sea breezes to develop across sheltered locations again Saturday afternoon.
AIRMET Sierra remains in effect for mountain obscuration for Kauai and Oahu this afternoon due to scatted low clouds and showers. However, this AIRMET will likely be dropped this evening or tonight as showers and cloud cover decrease.

Marine

A trough over the islands will dissipate tonight. Winds will weaken as this feature dissipates and remain mostly light through the weekend. The Small Craft Advisory that was in effect today will be allowed to expire at 6 pm HST this evening. A new high pressure system building north of the area will lead to an increasing trade wind flow Monday becoming breezy by Tuesday.
A northwest swell will continue to move through island waters over the next couple of days keeping surf elevated along exposed north and west facing shores. The northwest swell will decline slightly tonight before a reinforcement moves in late tonight through the weekend. A High Surf Advisory has been extended through the day Saturday for north and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui.
Elsewhere, a small to medium south swell will continue through this weekend.

Fire weather

Critical fire weather conditions are not anticipated due to increased moisture and rainfall chances associated with a surface trough between Kauai and Oahu, and weaker winds through the weekend. Trade winds will strengthen next week, but relative humidity values will be high enough to continue to preclude any critical fire weather conditions.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Saturday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Windward Haleakala.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters.

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Data Courtesy of NOAA.gov