West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 78 to 84. Northeast winds up to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 69 to 76. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 84. Northeast winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 40 percent.

South Side

Today: Breezy. Mostly sunny with isolated showers. Highs around 85. North 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 76. North winds up to 25 mph.

Tuesday: Sunny and breezy. Highs around 85. North winds up to 25 mph shifting to the northeast 10 to 25 mph in the afternoon.

North Shore

Today: Breezy. Mostly cloudy with scattered showers. Highs 80 to 87 near the shore to around 66 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 71 to 76 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Tuesday: 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.

Central Maui

Today: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs 78 to 86. East winds up to 25 mph shifting to the northeast 10 to 25 mph in the afternoon. Chance of rain 40 percent.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 70 to 75. East winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers. Highs 78 to 86. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Upcountry

Today: Partly sunny with scattered showers. Highs around 61 at the visitor center to around 66 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 47 at the visitor center to around 44 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 61 at the visitor center to around 67 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Mostly cloudy with scattered showers. Highs 80 to 87 near the shore to around 66 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 71 to 76 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Tuesday: 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.

Lanai City

Today: Breezy. Mostly sunny with isolated showers. Highs 73 to 80. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 66 to 71. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 73 to 80. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 70 to 86. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 60 to 75. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers. Highs 72 to 86. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

An unstable and somewhat wet trade wind pattern will continue through mid-week, with brief downpours possible. During the second half of the week, a strengthening area of high pressure north of the islands will increase stability across the region, producing drier, but windier conditions.

Discussion

This morning, local satellite and radar imagery shows just a few light scattered showers moving into the islands on moderate easterly trade wind flow. While some areas of the state received significant rainfall totals yesterday, shower intensity and coverage eased area-wide after sunset. With that said, the early morning sounding from Hilo continues to show over two inches of precipitable water, compared to the much drier Lihue sounding. Broad troughing aloft persists over the islands, and with this amount of ample moisture available, expect that a generally wet trade wind pattern will continue for the next couple of days with frequent showers over windward areas, especially for the Big Island. Some showers could produce brief downpours, similar to those that were observed this past weekend at times. Showers will generally favor windward areas during the overnight and morning hours, with scattered leeward showers developing during the afternoons. Additionally, dewpoints will continue to linger in the upper 60s to low 70s, which should make temperatures feel warmer than normal.
Increased stability and stronger trade winds are expected by Thursday. Latest global guidance remains in good agreement with a strong high developing far north of the state during the second half of the week, which should result in windy conditions. Winds could potentially reach Wind Advisory levels Thursday into Friday for select areas downstream of terrain. Drier conditions are also expected during this time, but scattered showers embedded within the windy trade wind flow will continue, especially during the night and early morning hours.

Aviation

Moderate to locally breezy trades expected for the next couple days. Low cigs and SHRA should primarily impact windward and mauka locations with some limited spillover to leeward areas. MVFR conds possible in heavier SHRA, otherwise VFR prevails.
AIRMET Sierra is in effect for mtn obsc for Kauai, Oahu, Maui and windward sections of the Big Island.

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 few days. This anchored high will strengthen and expand past mid week. The resultant tightening gradient will produce fresh to locally strong trades during the later half of the week.
A small size, short to medium period north northwest (320-330 degree) bump tonight into early Tuesday will provide an additional foot or two upon north-facing shore surf Tuesday.
The arrival of a couple of medium to long period south southwest (200 degree) swells the next few days will maintain seasonable surf along southern facing shores. Strengthening trades later this week will keep short period, elevated wind wave chop alive going into the weekend.
Water levels peaking between 2.5 to 3.0 ft MLLW during today's high tides may result in some minor overwash within low lying coastal areas.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov