West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 79 to 85. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows 70 to 76. East winds up to 20 mph. Chance of rain 40 percent.

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

South Side

Today: Sunny and breezy. Highs around 87. North winds up to 20 mph.

Tonight: Mostly clear. Breezy. Lows 71 to 79. North winds up to 20 mph decreasing to up to 10 mph after midnight.

Monday: 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.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 81 to 88 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 70 to 75 near the shore to around 57 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Partly sunny with scattered showers. Highs 79 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Isolated showers in the afternoon. Highs 80 to 88. 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 around 72. East winds up to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 86. East winds up to 25 mph shifting to the northeast 10 to 25 mph in the afternoon. Chance of rain 30 percent.

Upcountry

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 63 at the visitor center to around 66 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows around 51 at the visitor center to around 42 at the summit. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 50 percent.

Monday: Mostly sunny with scattered showers. Highs around 57 at the visitor center to around 65 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 81 to 88 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 70 to 75 near the shore to around 57 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Partly sunny with scattered showers. Highs 79 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Lanai City

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 73 to 80. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 30 percent.

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

Monday: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 72 to 80. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 30 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 74 to 87. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 61 to 75. East winds 10 to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Breezy. Isolated showers. Highs 71 to 86. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A slightly unstable and somewhat wet trade wind flow will continue into Monday. An increasingly stable, moderate to breezy trade wind flow will develop Tuesday and Wednesday and will persist into next weekend.

Discussion

Scattered heavy showers over windward areas diminished overnight as the upper level low that lingered over the area during the past couple of days lifted away to the northeast. A handful of windward stations picked up 1 to 2 inches of rainfall, mainly before midnight. Little rainfall managed to make it leeward areas since the local pressure gradient and resulting trade winds remained somewhat weak due to the effects of the upper low.
Moderate easterly winds and a somewhat wet pattern of mainly windward and mauka showers is expected over the next couple of days. The GFS and ECMWF show moisture remaining slightly elevated and dew points hanging on in the upper 60s to lower 70s, allowing the humid trade wind flow to continue to produce showers over windward areas. Broad troughing aloft will maintain some instability, which could still trigger a briefly heavy shower, mainly over the heated leeward slopes of the Big Island and Maui during the afternoon hours.
Increased stability and stronger trade winds are due late Tuesday or Wednesday. Expect a typical pattern of mainly windward rainfall and mostly dry conditions leeward into next weekend.

Aviation

Flight weather conditions will improve today as the upper level disturbance continues to drift eastward away from the Hawaiian Islands. Brief showers linger in the forecast mainly over windward and mountain areas of each island.
AIRMET Sierra remains in effect for mountain obscuration for the east section of Maui.

Marine

Moderate to locally fresh easterly trades have returned. An upper level-low that plagued the state has moved off to the northeast, increasing stability and decreasing showers.
A small, medium-period north northwest (320-330 degree) swell will continue to decline through tonight, with surf along north- facing shores following suit. A medium-period north-northwest reinforcement may provide another small bump in surf along north- facing shores by early Monday morning, followed by another small reinforcing swell on Tuesday.
Surf along west-facing shores will remain nearly steady through the rest of the weekend as the northwest swell influence gradually declines, but a new, long-period south southwest swell fills in.
A mix of small, medium- to long-period south swells will maintain small surf along south-facing shores for the next several days. The long-period south-southwest swell described above will increase surf along south-facing shores through today. Additional small, medium- to long-period south swell reinforcements will arrive through midweek.
Moderate to fresh trades will maintain rough and choppy surf along east-facing shores for the next several days.
Tides will peak around 2.5 to 3.0 ft MLLW today. Minor overwash of low lying coastal areas will be possible during times of high tide.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov