West Side

Today: Sunny and windy. Isolated showers in the morning. Highs 76 to 84. Northeast winds 15 to 30 mph decreasing to up to 30 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 70 to 75. Northeast winds up to 25 mph. Chance of rain 20 percent.

Wednesday: Breezy. Sunny with isolated showers. Highs 77 to 85. Northeast winds up to 20 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 85. Northeast winds up to 25 mph.

Tonight: Mostly clear. Breezy. Lows 69 to 78. Northeast winds 10 to 25 mph.

Wednesday: Sunny and breezy. Highs around 86. Northeast winds up to 20 mph.

North Shore

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs around 81 near the shore to around 65 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows around 72 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Wednesday: Breezy. Partly sunny with scattered showers. Highs around 81 near the shore to 65 to 70 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 80 to 85. Northeast winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 69 to 74. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 80 to 86. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Breezy. Mostly sunny with isolated showers. Highs around 61 at the visitor center to around 70 at the summit. East winds 10 to 25 mph decreasing to up to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 50 at the visitor center to around 47 at the summit. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 50 percent.

Wednesday: Windy. Mostly sunny with scattered showers. Highs 62 to 80. East winds 10 to 25 mph becoming up to 30 mph in the afternoon. Chance of rain 50 percent.

East Maui

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs around 81 near the shore to around 65 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows around 72 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Wednesday: Breezy. Partly sunny with scattered showers. Highs around 81 near the shore to 65 to 70 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Lanai City

Today: Windy. Mostly sunny with isolated showers. Highs 71 to 80. Northeast winds 10 to 25 mph becoming up to 30 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Windy. Lows 67 to 72. Northeast winds 10 to 30 mph.

Wednesday: Sunny and breezy. Highs 76 to 82. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 69 to 86. East winds up to 25 mph shifting to the northeast 10 to 25 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 61 to 76. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 76 to 87. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A breezy and stable trade wind flow will prevail through much of the week as surface high pressure holds north of the state. Pockets of moisture moving in the trades will focus rainfall over windward and mauka areas with showers briefly passing over leeward areas.

Discussion

Breezy trade winds continue for most areas, as a surface high has weakened slightly north of the area overnight. The Wind Advisory has been cancelled as wind speeds have dropped just below advisory levels. The soundings this morning show inversion heights continuing to hover around 5,000 and 7,000 ft producing stable conditions. Expect borderline advisory level, gusty winds to develop downslope of terrain, particularly for some leeward portions of Big Island and Maui later this afternoon and overnight tonight due to a slight strengthening of the high pressure system to the north and localized terrain enhancing effects. Will continue to monitor this afternoon if a Wind Advisory is warranted. Scattered, light showers can be seen on radar with showers focusing mainly along windward and mauka areas, with a few showers spilling over to leeward areas of the smaller islands. The majority of the shower activity is expected for Kauai and Oahu rest of the this morning. Shower activity is then expected to pick up across the state tonight into early morning Wednesday as a band of moisture moves through.
The stable breezy trade wind flow will persist through at least Friday. Surface high pressure will hold north of the islands and maintain breezy and gusty trade winds. Pockets of moisture within the trades will focus showers over windward areas, and stability from ridging aloft will keep shower intensity moderate.
The National Hurricane Center is monitoring a broad area of low pressure, currently well east-southeast of the Hawaiian Islands. Guidance thus far indicates minor, indirect effects such as trade wind speeds increasing as this system passes south Friday into the weekend and an increase in trade wind showers for windward Big Island. This area of low pressure is expected to pass south of the islands this weekend, but will need to be closely monitored as it continues to develop. Trade winds could ease slightly Sunday as a weakening front approaches. This feature may increase shower activity for Kauai Sunday or next Monday.

Aviation

A ridge to the north will maintain moderate to locally strong trade winds across the region. Clouds and showers will be focused over the windward slopes, but the strong winds could carry some showers to leeward areas at times. Generally VFR conditions are expected, with the exception of the windward side of the Big Island. AIRMET Sierra is in place there for mountain obscuration, and that will likely remain in place today.
AIRMET Tango remains in effect due to the mechanical turbulence to the lee of the mountains below 8000 feet. Anticipate this AIRMET to remain posted beyond 24 hours.

Marine

Dominant high pressure north of the area will maintain fresh to strong trade winds through most of the week and into the weekend with slight day to day fluctuations. The Small Craft Advisory (SCA) has been extended through Wednesday for the combination of winds for most waters and seas remaining near 10 feet today for areas exposed to a fading north-northwest swell. Continued strong trade winds will likely necessitate further extensions of the SCA. On Thursday, a broad area of low pressure with high potential to develop into a tropical cyclone according to National Hurricane Center forecasts will approach and pass south of the islands, potentially enhancing winds over southeast waters. Additionally, another moderate northwest swell is likely to push seas in exposed waters back above 10 ft through Friday. The threat of small craft winds and seas may extend into the weekend.
Surf along north- and west-facing shores will continue to decrease today as a moderate, north-northwest swell fades and shifts more northerly. A small, long period north-northwest swell arrives tonight and peaks late Wednesday, but this will not prevent north and west shore surf from dropping to small levels by Wednesday. Another moderate, long-period northwest swell arrives Wednesday night and will likely push north and west shore surf back to advisory levels Thursday into Friday. A medium-period swell fills in on Saturday, likely prolonging moderate to large surf action into the weekend.
The current small, medium-period south swell will continue to fade today. South shore surf will be small to tiny through much of the week with little southerly background energy reaching the islands. East-facing shores will see continued moderate trade wind swell as strong northeast winds remain. Surf along east-facing shores will stay big and choppy through much of the week with the trades.

Fire weather

Breezy winds during the next several days will produce moderate fire weather conditions since recent rainfall has likely limited the widespread availability of receptive fuels. The temperature inversion near Big Island will range from 6000 to 8000 ft over the next few days.

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, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov