West Side

Today: Sunny. Highs 81 to 87. East winds up to 15 mph.

Tonight: Mostly clear. Lows 68 to 76. East winds up to 15 mph.

Sunday: Sunny. Highs 80 to 86. Northeast winds up to 15 mph.

South Side

Today: Sunny. Highs around 89. North winds up to 15 mph.

Tonight: Mostly clear. Lows 66 to 77. North winds up to 15 mph.

Sunday: Sunny and breezy. Highs around 88. North winds up to 20 mph increasing to 10 to 20 mph in the afternoon.

North Shore

Today: Mostly sunny with scattered showers. Highs 82 to 87 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers. Lows around 72 near the shore to around 51 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Sunday: Mostly sunny with isolated showers. Highs 81 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Central Maui

Today: Sunny. Highs 81 to 89. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

Tonight: Mostly clear. Lows 66 to 73. Northeast winds 10 to 15 mph decreasing to up to 10 mph after midnight.

Sunday: Sunny and breezy. Highs 80 to 88. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon.

Upcountry

Today: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 64 at the visitor center to around 70 at the summit. East winds up to 10 mph in the morning becoming light. Chance of rain 40 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 42 to 57. Northeast winds up to 10 mph. Chance of rain 20 percent.

Sunday: Sunny. Isolated showers in the morning. Highs around 63 at the visitor center to around 69 at the summit. Northeast winds up to 10 mph. Chance of rain 20 percent.

East Maui

Today: Mostly sunny with scattered showers. Highs 82 to 87 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers. Lows around 72 near the shore to around 51 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Sunday: Mostly sunny with isolated showers. Highs 81 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Lanai City

Today: Sunny. Highs 73 to 82. Northeast winds up to 15 mph.

Tonight: Clear. Lows 66 to 71. Northeast winds 10 to 15 mph.

Sunday: Sunny. Highs 72 to 81. Northeast winds 10 to 15 mph.

Kaunakakai

Today: Sunny. Highs 72 to 89. East winds up to 15 mph.

Tonight: Clear. Lows 59 to 75. Northeast winds 10 to 15 mph decreasing to up to 15 mph after midnight.

Sunday: Sunny. Highs 70 to 88. Northeast winds up to 15 mph.

Detailed Forecast

Synopsis

Light to moderate east-southeasterly winds will persist today, then take on an east northeasterly component by Sunday. Despite the slight variation in wind direction, the light to moderate background flow will bring a combination of mainly isolated windward and mauka showers along with sea breeze induced leeward and interior showers. Early to mid- next week, trade winds will strengthen to moderate to breezy levels, bringing a return to more consistent windward showers.

Discussion

Mainly dry conditions prevailed overnight across the state with very little low cloud cover and isolated showers. Areas along the windward slopes saw most shower coverage, though only a few hundredths of an inch of accumulation were reported. A typical lower level moisture profile can be noted on the 12Z RAOB sounding at Hilo and Lihue with a capping boundary layer temperature inversion height of around 7,000 feet. Dry and stable air dominated in the mid and upper levels. Zooming out, a stationary front was analyzed to the northwest of the state and a 1029 mb surface high resided well to the northeast. These features should help maintain light to moderate east southeast flow today, backing to east northeast by Sunday. Despite the slight variation in wind direction, the light to moderate background flow will bring a combination of mainly isolated windward and mauka showers along with sea breeze induced leeward and interior showers. It may feel humid once again today with dewpoints hovering in the lower 70s. However, expect some relief for Sunday and beyond as we transition into a more traditional east northeast trade wind pattern and dewpoints gradually fall back into the mid to upper 60s.
Monday through Friday, the aforementioned frontal system northwest of the islands weakens into a trough, moves west, and is replaced by an large area of surface high pressure. Tightening local surface pressure gradients across the state will lead to moderate to locally breezy trade winds. In addition, both the GFS and ECMWF models deepen a longwave trough north of the islands, pinch off an upper low, and retrograde it to the west southwest. There still remains some variance between the global models on where this upper level low tracks, but as it nears the islands by midweek, it may enhance trade wind showers as batches of moisture roll through.

Aviation

Stable weather conditions will continue through the weekend as strong subsidence aloft limits vertical cloud development over the islands. Light to moderate trade winds will persist as a diminishing stationary front far north of the islands keeps the high pressure ridge in a weakened state. Trade winds strengthen by Monday. No AIRMETs in effect.

Marine

Light to moderate trades will hold for the next couple of days as a weak surface ridge remains northeast of the area and a front passes to the north. Trade winds will begin to increase Monday and trend upward through next week as the front dissipates and the ridge strengthens north of island chain.
A small, medium-period south swell will continue to fade while a new long-period south swell builds through the day. Surf along south and west-facing shores should trend upward by the afternoon and peak overnight before diminishing on Sunday. Multiple other small, medium to long period south and southeast swells also arrive through the middle of next week, which will maintain surf heights near seasonal averages.
Tiny surf will prevail along north-facing shores through most of the coming week as limited short-period energy reaches the islands from the north and northwest. Trade winds remain lighter than normal through the weekend, keeping surf along east-facing shores below average. East shore surf will begin to trend up early next week as trade winds increase across and upstream of the region.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov