West Side

Today: Sunny and breezy. Isolated showers in the afternoon. Highs 80 to 87. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly clear with isolated showers. Lows 71 to 79. Northeast winds up to 20 mph. Chance of rain 20 percent.

Friday: Sunny and breezy. Highs 81 to 87. Northeast winds up to 20 mph.

South Side

Today: Sunny and breezy. Highs around 89. North winds up to 20 mph.

Tonight: Mostly clear. Breezy. Lows 71 to 78. North winds up to 20 mph.

Friday: Sunny and breezy. Highs around 89. North winds up to 25 mph increasing to 10 to 25 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs around 82 near the shore to around 67 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 around 75 near the shore to around 56 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs around 83 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 81 to 89. Northeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon.

Tonight: Mostly clear. Breezy. Lows 71 to 77. East winds 10 to 20 mph decreasing to up to 15 mph after midnight.

Friday: Sunny and breezy. Isolated showers in the morning. Highs 81 to 89. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 64 at the visitor center to around 69 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows around 52 at the visitor center to around 46 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 64 at the visitor center to around 68 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs around 82 near the shore to around 67 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 around 75 near the shore to around 56 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs around 83 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Lanai City

Today: Mostly sunny. Isolated showers in the afternoon. Highs 73 to 82. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 67 to 73. Northeast winds up to 15 mph increasing to 10 to 15 mph after midnight.

Friday: Sunny and breezy. Highs 73 to 82. Northeast winds 10 to 20 mph.

Kaunakakai

Today: Sunny. Isolated showers in the afternoon. Highs 71 to 90. East winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 62 to 77. East winds 10 to 15 mph.

Friday: Sunny. Highs 71 to 89. Northeast winds 10 to 15 mph.

Detailed Forecast

Synopsis

Trade winds will gradually increase through tomorrow and will by locally breezy through most of the weekend. Winds will ease a bit early next week. Fairly typical summertime weather is expected through the week, with showers favoring windward and mauka areas.

Discussion

Trade winds will back out of a more typical east-northeast direction and increase today. The local pressure gradient and resulting trades will strengthen as a mid-level trough moves away to the west and robust surface high pressure holds far northeast of the islands. A pocket of moisture moving along the trade wind flow will be focused over windward Big Island through the morning, with a lesser amount of shower activity expected on other windward slopes. A ridge aloft will maintain stable conditions that will limit shower intensity and keep windward rainfall totals on most islands less than a quarter of an inch today. Aside from scattered afternoon showers on the Kona slopes, leeward areas will experience little rainfall.
Typical summertime trade wind weather will prevail Friday through the weekend. Trades will become locally breezy as the surface high remains parked to the northeast and broad areas of low pressure pass well south of the islands in the deep tropics. Stable and somewhat dry conditions will keep modest shower activity focused over windward areas.
Trades will ease slightly late Sunday into the first half of next week. Little to no organized areas of moisture are seen in the guidance, suggesting continued mainly windward showers.

Aviation

Moderate trades expected for next few days. Low cigs and SHRA will impact windward and mauka locations. MVFR conds possible in SHRA, otherwise VFR prevails.
No AIRMETs in effect.

Marine

High pressure far north of the islands and very broad weak troughing to the west is leading to a slightly veered and lighter trade wind flow across the coastal waters this morning. The pressure gradient is expected to strengthen today as the high pressure to the north dips south, causing an uptick in trade wind speeds by this afternoon and continuing through the weekend. As the trades gradually strengthen to fresh to strong levels today, a Small Craft Advisory has been issued for the windier channels and waters around Maui County and the Big Island through Friday afternoon. This will likely need to be extended through at least Saturday before weakening high pressure to the north allows winds to diminish again.
A small, long-period west-northwest swell from former Super Typhoon Bavi will maintain similar surf heights along west-facing and north- facing shores today (as compared to yesterday) before gradually subsiding tonight into the weekend. This swell is overlapping for some west-facing shores with a gradually fading small, medium-period southwest Tasman swell that will produce somewhat below average surf for south-facing shores today. North-facing shores return to flat to tiny surf by this weekend with the loss of the west-northwest swell.
Surf returns to near average for south-facing shores late Friday with a reinforcing small, long-period south-southwest swell. This swell then fades through the weekend. A moderate, long-period south swell will arrive Sunday and build through early next week, bringing the potential for above-average (though sub-advisory) surf.
Surf along east-facing shores will be slightly below seasonal averages through Thursday with lighter trade winds, then climb back up a notch as trades strengthen through the weekend. Early to midweek next week, there's potential for a small, long- to medium-period swell to arrive, generated from Tropical Storm Elida.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov