West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 78 to 84. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 69 to 75. Northeast winds 10 to 20 mph.

Wednesday: Sunny and breezy. Isolated showers in the morning. Highs 77 to 83. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 85. North winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 68 to 76. Northeast winds up to 20 mph.

Wednesday: Sunny and breezy. Highs around 84. Northeast winds up to 20 mph shifting to the north 10 to 20 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 80 to 87 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 71 to 76 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 79 to 85 near the shore to around 64 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Central Maui

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 78 to 86. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 68 to 75. East winds 10 to 25 mph.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 78 to 84. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly cloudy with scattered showers. Highs around 62 at the visitor center to around 67 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 49 at the visitor center to around 44 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 59 at the visitor center to around 67 at the summit. East winds 10 to 25 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 80 to 87 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 71 to 76 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 79 to 85 near the shore to around 64 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Lanai City

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 73 to 80. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 66 to 71. Northeast winds 10 to 20 mph.

Wednesday: Sunny and breezy. Highs 72 to 80. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Sunny and breezy. Highs 71 to 86. East winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Lows 60 to 75. Northeast winds 10 to 20 mph.

Wednesday: Sunny and breezy. Highs 70 to 85. East winds 10 to 25 mph.

Detailed Forecast

Synopsis

An unstable and somewhat wet trade wind pattern will continue through tonight, with brief downpours possible. From Wednesday into early next week, an area of high pressure north of the islands will push drier air into the region. Trades are expected to become windy by Thursday and Friday, then will gradually ease back to locally breezy levels this weekend.

Discussion

Early this morning, local radar imagery shows just a few light scattered showers moving into the islands on locally breezy easterly trade wind flow. Similar to the day prior, the heavier showers that occurred at select spots yesterday quickly diminished during the late afternoon and evening, leaving only light, isolated showers favoring windward areas overnight. Regional satellite imagery early this morning does show a few bands of moisture upstream of the state, however, and although moisture content has decreased from the previous couple of days, the early morning 12z soundings from Lihue and Hilo still show ample precipitable water available.
Drier air is forecast to arrive from tonight into Wednesday night as high pressure north of the state strengthens. In the meantime, expect a relatively wet trade wind weather pattern to continue, with moderate to briefly heavy rain from showers that will generally favor windward and mauka areas, as well as the Kona slopes of the Big Island during the afternoon.
From late Wednesday onward, precipitable water values are anticipated to decrease back down to around 1 inch, and this drier air will persist into next week. Increased stability and stronger trade winds are expected by Thursday. Latest global guidance remains in good agreement with the high to our north strengthening, which should result in windy conditions across the region. Winds could potentially reach Wind Advisory levels Thursday into Friday for some areas, then decreasing back to locally breezy levels during the second half of the weekend.

Aviation

Moderate to locally breezy trades expected hold for the next couple days. Brief periods of low ceilings and showers will primarily affect windward mountain areas. MVFR conds possible in heavier SHRA, otherwise VFR prevails.
AIRMET Sierra remains in effect for mountain obscuration for windward Kauai, Maui and the entire area of the Big Island. These conditions will diminish later this morning.

Marine

The pressure gradient back from a surface high centered about 1,400 nautical miles northeast of the islands remains tight enough to support moderate to locally fresh trades the next couple of days. The anchored high will expand and strengthen through mid to late week. The resultant very tight gradient back across the Central Pacific will produce fresh to locally strong to near gale force nearshore winds the later half of the week. A Small Craft Advisory (SCA) is currently in effect over the windier zones surrounding Maui County and Big Island. The SCA will likely be expanded in area later this week to account for more areawide strengthened trades.
A small size, short to medium period north northwest swell is expected to fill in through the day. A gale low skirting the Aleutian Islands the next couple of days will send the tail ends of small north northwest swells through late this week.
A series of small, long period south southwest swells will provide near summer average size surf along south-facing shores throughout the week. Strengthening trades later this week will keep short period, elevated eastern wind wave chop alive well into the weekend.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov