Photo Credit: Brittney Cruz

West Side

Today: Breezy. Mostly cloudy with isolated showers. Highs 73 to 82. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows 62 to 69. East winds 15 to 20 mph. Chance of rain 20 percent.

Wednesday: Breezy. Partly sunny with isolated showers. Highs 75 to 81. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

South Side

Today: Breezy. Mostly cloudy with isolated showers. Highs around 84. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Breezy. Lows around 63. Northeast winds 10 to 20 mph.

Wednesday: Partly sunny. Breezy. Isolated showers in the afternoon. Highs around 81. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

North Shore

Today: Breezy. Mostly cloudy with scattered showers. Highs 73 to 79 near the shore to around 62 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 60 to 66 near the shore to 44 to 49 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely in the afternoon. Highs 73 to 78 near the shore to around 57 near 5000 feet. East winds 10 to 20 mph. Chance of rain 60 percent.

Central Maui

Today: Breezy. Mostly cloudy with isolated showers. Highs 78 to 83. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Breezy. Isolated showers after midnight. Lows 61 to 66. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Breezy. Partly sunny with isolated showers. Highs 77 to 82. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly cloudy with scattered showers. Highs around 58 at the visitor center to around 52 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 42 at the visitor center to around 36 at the summit. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Wednesday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 52 at the visitor center to around 47 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Mostly cloudy with scattered showers. Highs 73 to 79 near the shore to around 62 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 60 to 66 near the shore to 44 to 49 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely in the afternoon. Highs 73 to 78 near the shore to around 57 near 5000 feet. East winds 10 to 20 mph. Chance of rain 60 percent.

Lanai City

Today: Breezy. Mostly cloudy with isolated showers. Highs 70 to 78. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Breezy. Isolated showers in the evening. Lows around 64. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Mostly cloudy. Breezy. Isolated showers in the afternoon. Highs 70 to 77. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly cloudy with isolated showers. Highs 63 to 84. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Breezy. Isolated showers after midnight. Lows 57 to 69. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Breezy. Partly sunny with isolated showers. Highs 70 to 80. East winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds will continue through Thursday, delivering showery low clouds to windward and mauka areas, with a few showers spreading to leeward communities as well. High clouds will continue to stream overhead during the next several days as well, bringing considerable cloudiness at times. Unsettled and wet weather is expected Thursday night through New Years Day, with southeasterly winds bringing periods of moderate to heavy rainfall to the islands.

Discussion

Currently at the surface, a broad area of low pressure is located around 800 miles west-southwest of Kauai, with a large area of deep convection between the low and the Garden Isle. Meanwhile, a strong 1041 mb high centered around 1650 miles north of Honolulu remains the dominant weather feature locally, and continues to drive moderate to locally breezy trade winds across the island chain early this morning. Infrared satellite imagery shows a mix of high and low clouds resulting in partly to mostly cloudy conditions across the state. Radar imagery shows scattered showers moving into windward areas, with mainly dry conditions in leeward communities. Main short term concerns revolve around rain chances and trade wind trends.
The broad area of low pressure west of the state will weaken into a trough as it shifts southward today, with the trough then remaining nearly stationary in the vicinity of 170W through Thursday. Meanwhile, strong high pressure will remain anchored to the distant north through Wednesday, before shifting slowly southeastward and gradually weakening Wednesday night and Thursday. The pressure gradient will remain rather tight during this time, with moderate to locally breezy trade winds expected.
Model solutions remain in relatively good agreement showing an area of low pressure developing along the surface trough in the vicinity of 170W Thursday night. The low is then expected to lift northward and eventually northwestward Friday through the weekend, while the strong high north of the state shifts southeastward and weakens. Winds are forecast to shift around to the southeast at moderate speeds Thursday night and Friday, with light to moderate south to southeast winds following over the weekend into into early next week.
As for the remaining weather details, we should see a fairly typical trade wind shower regime hold in place through Wednesday, with showers favoring windward and mauka areas. With moderate to breezy trades holding in place, showers will reach leeward communities at times as well. Scattered to broken convective debris clouds will continue to stream over the islands during the next several days, bringing periods of considerable cloudiness to the island chain.
Model solutions remain in good agreement showing weather conditions deteriorating heading into New Years Eve. Deeper moisture will begin to advect into the state from the east Wednesday night and Thursday, bringing an increase in coverage and intensity of the trade wind showers. With winds swinging around to the southeast Thursday night and New Years Eve, we should see a confluence of deep moisture advecting in from the east as well as lifting northward from the Intertropical Convergence Zone. The result appears to be an extended period of wet weather, with moderate to heavy rainfall impacting the island chain at times Thursday night through New Years Day. Considerable cloud cover looks likely during this time, with periods of snow possible for the Big Island summits as well. Forecast confidence diminishes Sunday through early next week, as there are indications that conditions could improve as well as signs that unsettled weather could continue. Given the uncertainty will follow a middle of the road solution until details become more clear.

Aviation

Breezy easterly flow will persist through the remainder of this morning. Thus, scattered showers will be focused mainly along the windward portions of the islands. Isolated activity expected elsewhere. These showers may bring brief periods of MVFR ceilings and visibility, but not expecting anything widespread.
AIRMET TANGO remains in effect below 8000 feet over and immediately south through west of mountains on all islands due to tempo moderate turbulence.

Marine

High pressure to the north the islands will maintain fresh to strong trade winds across the coastal waters through Wednesday, with some weakening expected during the second half of the week. A developing surface low to the northwest of Kauai during the second half of the week will help to shift winds to a more southeasterly direction by the end of the week.
A Small Craft Advisory (SCA) remains in effect for most coastal waters and has been extended through Wednesday afternoon. Winds will trend down during the second half of the week, which will likely lead to scaling back of the SCA. The threat for thunderstorms will remain over the southwest offshore waters.
A west-northwest swell will continue today before fading tonight. Surf is expected to peak just below advisory levels for north and west facing shores of Kauai with this swell. The current east- northeast swell, combined with the strong east trades, will maintain rough and choppy surf along east facing shores, but is expected to remain just below advisory levels. A couple other northwest swells are expected to arrive Wednesday night and also Thursday night, but heights with these swells are currently expected to be about half of the swell expected tonight.

HFO Watches/Warnings/Advisories

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

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov