Photo Credit: Tyler Rooke

West Side

Today: Sunny. A 20 percent chance of showers in the afternoon. Highs 81 to 89. Northeast winds 10 to 15 mph.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows 65 to 72. Northeast winds 10 to 15 mph.

Saturday: Mostly sunny with a 20 percent chance of showers. Highs 79 to 87. Northeast winds 10 to 15 mph.

South Side

Today: Sunny. Highs around 87. North winds 10 to 15 mph.

Tonight: Mostly clear. Breezy. Lows around 66. North winds 15 to 20 mph.

Saturday: Sunny. Highs 83 to 88. North winds around 15 mph.

North Shore

Today: Mostly sunny. Chance of showers in the morning, then slight chance of showers in the afternoon. Highs 80 to 86 near the shore to 63 to 68 near 5000 feet. North winds around 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with a 40 percent chance of showers. Lows 62 to 69 near the shore to around 52 near 5000 feet. Northeast winds 10 to 15 mph.

Saturday: Partly sunny with chance of showers early in the morning, then mostly sunny with slight chance of showers in the late morning and afternoon. Highs 78 to 84 near the shore to around 65 near 5000 feet. Northeast winds around 10 mph. Chance of rain 40 percent.

Central Maui

Today: Sunny. Highs around 88. Northeast winds 10 to 15 mph.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows 64 to 70. Northeast winds 10 to 15 mph.

Saturday: Mostly sunny. A 20 percent chance of showers in the morning. Highs 84 to 89. Northeast winds 10 to 15 mph.

Upcountry

Today: Sunny. Highs around 61 at the visitor center to around 58 at the summit. Northwest winds around 10 mph.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows around 47 at the visitor center to around 44 at the summit. North winds around 10 mph shifting to the west after midnight.

Saturday: Mostly sunny with a 20 percent chance of showers. Highs around 61 at the visitor center to around 59 at the summit. Light winds.

East Maui

Today: Mostly sunny. Chance of showers in the morning, then slight chance of showers in the afternoon. Highs 80 to 86 near the shore to 63 to 68 near 5000 feet. North winds around 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with a 40 percent chance of showers. Lows 62 to 69 near the shore to around 52 near 5000 feet. Northeast winds 10 to 15 mph.

Saturday: Partly sunny with chance of showers early in the morning, then mostly sunny with slight chance of showers in the late morning and afternoon. Highs 78 to 84 near the shore to around 65 near 5000 feet. Northeast winds around 10 mph. Chance of rain 40 percent.

Lanai City

Today: Sunny. Highs 73 to 82. Northeast winds 10 to 15 mph.

Tonight: Mostly clear. Breezy. Lows around 67. Northeast winds 15 to 20 mph.

Saturday: Sunny. A 20 percent chance of showers in the late morning and afternoon. Highs 73 to 82. Northeast winds around 15 mph.

Kaunakakai

Today: Mostly sunny. Breezy. A 20 percent chance of showers in the afternoon. Highs 76 to 87. Northeast winds 10 to 20 mph.

Tonight: Breezy. Partly cloudy with a 20 percent chance of showers. Lows 60 to 71. Northeast winds 10 to 20 mph.

Saturday: Sunny. A 20 percent chance of showers in the morning. Highs 76 to 87. Northeast winds 10 to 15 mph.

Detailed Forecast

Synopsis

High pressure northwest of the islands will move slowly east the next couple of days. This will support increasing and locally breezy northeasterly trade winds later today into Saturday, with winds turning toward the east and gradually weakening again on Sunday. A mostly dry weather pattern is expected to develop over the weekend as a drier air mass moves in, and the atmosphere becomes more stable. Winds will trend weaker Monday and Tuesday as another front approaches, with mostly dry weather persisting. The front may move over the islands around the middle of next week.

Discussion

A weak frontal boundary that was analyzed over the islands yesterday evening has become increasingly diffuse and difficult to identify overnight, with a band of broken to overcast low clouds near Kauai and Oahu representing some of the remnant moisture. Meanwhile, skies over Maui and the Big Island have cleared overnight, with radar only detecting a few showers within the cloud band near Kauai. On the large scale, light N to NE winds prevail, which has allowed offshore- flowing land breezes to develop over land. Overnight soundings show that the island atmosphere remains moist and somewhat unstable, although a trough aloft over the area is weakening.
The forecast anticipates a drying trend over the next 24 hours, with stable weather persisting through early next week as a mid-level ridge builds over the area from the W. Moderate to locally breezy NE trade winds gradually build today into tonight as a high to the NW moves gradually E, and a relatively dry NE trade wind flow is expected Saturday as a drier air mass brings lowering dew points. The weather over the islands looks to remain fairly benign as winds trend lighter and easterly on Sunday. A few windward showers will be possible, and maybe a pop-up shower will develop over leeward areas Sunday afternoon due to sea breeze convergence.
The high will move into the NE Pacific early next week, and a front associated with a rapidly developing low passing far N of the islands will force the ridge S over the islands. Winds will become light and variable Monday and Tuesday, with land and sea breezes modulating island weather to a degree. Thereafter, the forecast becomes increasingly uncertain, with guidance offering different outcomes with the front. GFS guidance continues to indicate a progressive and relatively weak frontal boundary moving quickly through the island chain, followed by strong NE winds Wednesday and Thursday. Meanwhile, ECMWF guidance depicts a cut-off low developing N of the islands along the front, slowing it's forward speed and stalling it W of the islands, leading to light and variable winds over the area. Current long-range forecast grids lean toward the GFS solution of a progressive front followed by stronger NE winds, but indicates winds of slightly weaker magnitude.

Aviation

High pressure building in from the northwest will usher in a cooler, drier air mass for the weekend. The front has dissipated. Moderate trade winds will build in from the west by Saturday afternoon.
At 2 AM Friday, late night satellite imagery revealed a band of remnant moisture draped across Kauai and westernmost Oahu. Corresponding radar imagery revealed scattered light showers to be associated with this band. Conditions are expected to shift eastward during the day, today, and should be draped across Oahu and Maui County by late afternoon.
The air mass over the Big Island remains moist and slightly unstable. Showery conditions will return to the island this afternoon when gentle sea breezes prompt cumulus buildups over the island's interior. Be prepared for brief MVFR CIG and VIS in moderate showers, especially along the leeward slopes, late this afternoon and through the evening hours.

Marine

North to northeast winds will gradually fill in down the island chain through the day as the low to the northeast weakens and moves further east. High pressure to the northwest will gradually shift eastward through the weekend to support this wind regime. Winds will likely ease again early next week as a weak surface ridge moves closer to the islands from the north.
A new north swell has begun to rise on the offshore buoy (51101) northwest of the state. Nearshore buoy north of Kauai has started to notch up in the early morning hours. The swell is expected to build in and approach the advisory threshold of 15 feet before gradually lowering through the weekend. A High Surf Advisory (HSA) may be issued if the swell comes in higher than guidance. Another north- northwest swell is forecast to arrive early next week, potentially producing another round of near advisory level surf for north facing shores. An even larger north swell is anticipated around the middle of next week although confidence remains low.
A small, long-period south swell will continue to slowly fill in, and will boost surf along south-facing shores to near the summertime average through Saturday, before returning to mainly background levels Sunday through early next week.
East shore surf will remain well below average for the next couple of days due to the lack of trades over and upstream of the islands except for east shores exposed to the north swell.

HFO Watches/Warnings/Advisories

None.

Maui Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov