Photo Credit: Jeni Ji Cousins

West Side

Today: Mostly sunny, with a high near 84. Windy, with an east northeast wind 16 to 24 mph, with gusts as high as 34 mph.

Tonight: Isolated showers after midnight. Mostly clear, with a low around 66. Windy, with an east northeast wind 16 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Saturday: Isolated showers before noon. Mostly sunny, with a high near 85. Breezy, with an east northeast wind 10 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 20%.

South Side

Today: Isolated showers after noon. Partly sunny, with a high near 86. Calm wind becoming west 5 to 7 mph. Chance of precipitation is 20%.

Tonight: Partly cloudy, with a low around 65. Light and variable wind.

Saturday: Isolated showers after noon. Partly sunny, with a high near 85. Light and variable wind becoming northeast 8 to 13 mph in the morning. Chance of precipitation is 20%.

North Shore

Today: Isolated showers before noon. Mostly sunny, with a high near 84. Windy, with a northeast wind 20 to 25 mph, with gusts as high as 36 mph. Chance of precipitation is 20%.

Tonight: Scattered showers, mainly after midnight. Partly cloudy, with a low around 65. Breezy, with an east wind 16 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Scattered showers before noon. Mostly sunny, with a high near 84. Windy, with a northeast wind 17 to 26 mph, with gusts as high as 38 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Central Maui

Today: Mostly sunny, with a high near 84. Windy, with a north northeast wind 11 to 16 mph increasing to 18 to 23 mph in the morning. Winds could gust as high as 32 mph.

Tonight: Scattered showers after midnight. Mostly clear, with a low around 64. Breezy, with an east northeast wind 9 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Scattered showers before noon. Mostly sunny, with a high near 84. Windy, with a north northeast wind 9 to 14 mph increasing to 19 to 24 mph in the afternoon. Winds could gust as high as 34 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Upcountry

Today: Mostly sunny, with a high near 71. West wind 5 to 8 mph becoming light and variable in the afternoon.

Tonight: Mostly clear, with a low around 55. Light and variable wind.

Saturday: Mostly sunny, with a high near 71. Light and variable wind becoming east 9 to 14 mph in the morning. Winds could gust as high as 18 mph.

East Maui

Today: Scattered showers. Mostly cloudy, with a high near 81. East wind 6 to 13 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after midnight. Mostly cloudy, with a low around 62. Southeast wind 3 to 8 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Showers likely, mainly before noon. Mostly cloudy, with a high near 82. Breezy, with a light southeast wind becoming east 10 to 15 mph in the morning. Winds could gust as high as 21 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Lanai City

Today: Isolated showers after 1pm. Partly sunny, with a high near 76. Windy, with an east northeast wind 7 to 12 mph increasing to 18 to 23 mph in the afternoon. Winds could gust as high as 32 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before 7pm. Partly cloudy, with a low around 63. Breezy, with an east northeast wind 17 to 22 mph decreasing to 11 to 16 mph after midnight. Winds could gust as high as 31 mph. Chance of precipitation is 20%.

Saturday: Isolated showers after 1pm. Partly sunny, with a high near 74. Breezy, with an east northeast wind 10 to 18 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.

Kaunakakai

Today: Mostly sunny, with a high near 83. Breezy, with an east northeast wind 10 to 17 mph, with gusts as high as 24 mph.

Tonight: Isolated showers after midnight. Mostly clear, with a low around 70. Breezy, with an east northeast wind 11 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 20%.

Saturday: Isolated showers before noon. Mostly sunny, with a high near 82. Breezy, with an east northeast wind 11 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Moderate to breezy easterly trade winds will persist through the weekend, with clouds and showers favoring windward and mountain locations. Windward shower coverage could increase later today through Saturday night as an upper low moves through from north to south. Warm and humid conditions, along with increasing rainfall chances, may return early next week as the trade winds diminish ahead of an approaching front.

Discussion

The surface trough northwest of Kauai that disrupted the trade winds earlier in the week will continue retreating westward and away from the area today. Easterly trade winds have returned, and will likely become breezy over the weekend as high pressure builds to the north. Windward showers may increase later today through Saturday night as an upper low drops southward into the area. Some showers could reach leeward locations as the inversion weakens and the trades increase – especially through the overnight and early morning hours. In addition to the increasing shower coverage, a thunderstorm or two can’t be ruled out over the Big Island slopes through the afternoon hours today and Saturday.
Models show the upper low briefly drifting south of the state Sunday through Sunday night, then lifting back through the area and merging with an upper trough passing to the north Monday through Tuesday. The subtropical ridge will weaken once again as a front approaches the region from the northwest. If this scenario evolves, a land and sea breeze regime, along with warm and humid conditions, will return and continue through the first half of next week. Rainfall chances will trend up through this time, with the best coverage setting up over interior and leeward locations through the afternoon hours.

Aviation

A high pressure ridge north of the Hawaiian Islands will maintain moderate trade winds today and tonight. Periods of mountain obscurations are possible for windward slopes, especially over the eastern slopes of Maui and the Big Island as cloud bands drift through the region. An upper level low north of the island chain will drift south across the state through Saturday. Instability with this upper low will likely enhance shower activity mainly over windward and mountain locations.
No AIRMETs are in effect. However mountain obscurations may be needed for windward Big Island later this morning.

Marine

A surface high passing north of the islands today will maintain fresh to locally strong trade winds through the weekend. A small craft advisory is in effect to until 6 am HST Sunday for the windier waters of Maui County and waters south of the Big Island. Trade winds are expected to trend down and become southeast on Monday, ahead of an approaching front from the northwest.
A northwest swell has peaked and will be subsiding slowly through Saturday. A small west-northwest swell is tabbed to arrive late Monday, peak Tuesday, then subside gradually through Wednesday. The source of this swell is from a long lived distant typhoon. A small short period northwest pulse is slated to arrive Wednesday night and Thursday.
Small surf will continue along the south facing shores into next week due to a series of long period swell from the southern hemisphere. The boost in the trade winds will raise the surf into the small to moderate range along the east facing shores into the weekend. The surf will trend smaller after Sunday as the trade wind diminishes.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov