Photo Credit: Tyler Rooke

West Side

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 81. East winds up to 20 mph. Chance of rain 40 percent.

Tonight: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 61 to 67. East winds up to 20 mph shifting to the northeast 10 to 20 mph after midnight. Chance of rain 40 percent.

Friday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 82. Northeast winds up to 20 mph. Chance of rain 40 percent.

South Side

Today: Mostly sunny. Breezy. Highs around 81. North winds up to 10 mph increasing to up to 20 mph in the afternoon.

Tonight: Mostly clear. Lows around 62. North winds up to 15 mph.

Friday: Mostly sunny. Breezy. Highs around 82. North winds 10 to 20 mph.

North Shore

Today: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers and isolated thunderstorms in the afternoon. Highs 73 to 78 near the shore to around 58 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers and isolated thunderstorms early in the evening, then showers likely in the late evening and overnight. Lows 59 to 65 near the shore to 43 to 48 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 70 percent.

Friday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 74 to 79 near the shore to around 60 near 5000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Central Maui

Today: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 77 to 82. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Isolated showers. Lows 60 to 65. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Friday: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 78 to 83. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with scattered rain showers in the morning, then partly sunny with scattered rain showers and isolated thunderstorms in the afternoon. Highs around 53 at the visitor center to around 48 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy early in the evening then becoming partly cloudy. Scattered rain showers and isolated thunderstorms early in the evening, then scattered rain showers in the late evening and overnight. Lows around 41 at the visitor center to around 35 at the summit. Northeast winds up to 15 mph. Chance of rain 50 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Scattered rain showers. Highs around 54 at the visitor center to around 50 at the summit. East winds up to 10 mph. Chance of rain 50 percent.

East Maui

Today: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers and isolated thunderstorms in the afternoon. Highs 73 to 78 near the shore to around 58 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers and isolated thunderstorms early in the evening, then showers likely in the late evening and overnight. Lows 59 to 65 near the shore to 43 to 48 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 70 percent.

Friday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 74 to 79 near the shore to around 60 near 5000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Lanai City

Today: Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 72 to 79. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers early in the evening, then partly cloudy in the late evening and overnight. Lows around 63. Northeast winds up to 15 mph increasing to 10 to 20 mph after midnight. Chance of rain 20 percent.

Friday: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 73 to 80. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaunakakai

Today: Partly sunny. Breezy. Isolated showers in the morning. Highs 70 to 80. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 55 to 67. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Partly sunny. Breezy. Isolated showers in the morning. Highs 71 to 81. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light to moderate northeast to east trade winds will continue through Friday, with clouds and showers favoring windward and mauka locations. A few heavy showers and thunderstorms will remain possible over the eastern end of the state through tonight due to an upper low in the area. Winds will shift out of the north-northeast direction over the weekend, with the best rainfall chances remaining over and around the Big Island.

Discussion

Guidance shows the trade wind conditions continuing through Friday, with clouds and showers favoring windward and mauka locations. A weak surface trough in the area will keep northeast trades over Kauai and Oahu, with east to southeast trades holding over the eastern end of the state. Although the surface trough and an upper low centered over the islands will support localized heavy showers and thunderstorms over the Big Island and Maui into tonight, most of the enhanced shower activity should remain east of the state where a plume of deep moisture is located. This upper low is forecast to fill and lift northeast of the area Friday.
Over the weekend and early next week, winds are forecast to back to a more northerly direction as a ridge noses southeastward into the area and low pressure closes off far to the north. For Oahu and Kauai, limited moisture (GFS PWs dipping to .5 to .75 inches by Sunday) associated with the northerly flow will limit rainfall chances – even for windward and northern facing slopes. For the eastern end of the state, the aforementioned plume of deeper moisture lingering in the area combined with a pulse moving through aloft will support the best rainfall chances across the area. Confidence in the details for early next week remains low due to significant differences between model sources.

Aviation

The upper low over the Hawaiian islands will remain in place through early evening then weaken and gradually shift northward. The upper low has destabilized the air mass over the state. Morning soundings at Lihue and Hilo reveal no sign of a trade wind inversion. This combined with ample moisture in the lower levels over the eastern end of the state, will create ideal conditions for vigorous afternoon shower activity over the Big Island. Mountain obscuration could become an issue for Windward Big Island this afternoon or evening.
Across the smaller islands, low level winds will steer light to moderate, mostly isolated showers towards north and northeast facing slopes and coasts. Brief MVFR CIG or VIS are to be expected in passing showers, otherwise VFR conditions will predominate through twenty-four hours and beyond.

Marine

A surface high pressure system remains far northeast of the islands early this morning, but a surface trough lies just northeast and east of the Big Island. An area of strong east to southeast winds to the east of this trough is producing elevated, rough seas over portions of the Big Island Windward Waters. Therefore, a Small Craft Advisory (SCA) has been issued for that marine zone through early Friday morning. Elsewhere, the close proximity of the surface trough to the state continues to disrupt the pressure gradient. As a result, there are light to moderate northeast to east trade winds over most waters in the vicinity of of the islands.
Expect light to locally moderate northeast winds to persist across most Hawaiian waters into this weekend. We do not anticipate SCA conditions from late Friday into this weekend due to winds or seas based on the latest forecast guidance.
The current west-northwest swell has been gradually lowering overnight. However, it still is producing elevated surf along exposed north and west facing shorelines. Therefore, the High Surf Advisory (HSA) has been extended through this morning for the north and west facing shores of Kauai, Niihau, Oahu, and Molokai, for north facing shores of Maui, and for west facing shores of the Big Island. The west-northwest swell will continue to gradually lower from later today and tonight into Friday before a new northwest swell arrives Friday night. Surf produced by this northwest swell is expected to peak below the HSA criteria along north and west facing shores on Saturday, before it gradually subsides from Saturday night into early next week. A small north swell with a wave period of around 10 seconds may arrive Sunday, which might provide a slight boost in surf heights along north facing shores early next week.
The out-of-season south swell, which has been keeping surf along south facing shores above our typical wintertime flat conditions, will eventually lower from tonight through Friday. Surf will return to more typical background conditions along south facing shores from this weekend into early next week. Expect modest surf along east facing shores through this evening. Surf is expected to increase to near the seasonal average along east facing shores from Friday into this weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until noon HST today for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Windward Haleakala, Big Island South.
Small Craft Advisory until 6 AM HST Friday for Big Island Windward Waters.

Maui Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov