West Side

Tonight: Partly cloudy. Breezy. Isolated showers early in the evening. Lows 64 to 73. East winds up to 20 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with scattered showers. Highs 75 to 87. East winds up to 15 mph. Chance of rain 40 percent.

Saturday Night: Mostly clear with isolated showers. Lows 64 to 73. East winds up to 15 mph. Chance of rain 20 percent.

South Side

Tonight: Mostly clear. Isolated showers early in the evening. Lows 65 to 70. Northwest winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Highs 78 to 89. Northwest winds up to 10 mph.

Saturday Night: Partly cloudy. Lows around 68. Northwest winds up to 10 mph shifting to the northeast after midnight.

North Shore

Tonight: Mostly cloudy. Breezy. Scattered showers early in the evening, then numerous showers in the late evening and overnight. Lows 68 to 73 near the shore to around 53 near 5000 feet. Southeast winds 10 to 20 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Breezy. Scattered showers until late afternoon, then numerous showers late in the afternoon. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Saturday Night: Breezy. Mostly cloudy with scattered showers. Lows around 70 near the shore to around 53 near 5000 feet. East winds up to 20 mph becoming 10 to 15 mph after midnight. Chance of rain 50 percent.

Central Maui

Tonight: Partly cloudy. Breezy. Scattered showers early in the evening. Lows around 67. East winds up to 20 mph decreasing to up to 10 mph after midnight. Chance of rain 30 percent.

Saturday: Mostly sunny. Breezy. Isolated showers in the late morning and afternoon. Highs 83 to 90. East winds up to 20 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Breezy. Lows 65 to 70. East winds up to 20 mph.

Upcountry

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 43 at the visitor center to around 41 at the summit. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 51 to 69. East winds up to 15 mph. Chance of rain 50 percent.

Saturday Night: Mostly cloudy with scattered showers. Lows around 44 at the visitor center to around 41 at the summit. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

East Maui

Tonight: Mostly cloudy. Breezy. Scattered showers early in the evening, then numerous showers in the late evening and overnight. Lows 68 to 73 near the shore to around 53 near 5000 feet. Southeast winds 10 to 20 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Breezy. Scattered showers until late afternoon, then numerous showers late in the afternoon. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Saturday Night: Breezy. Mostly cloudy with scattered showers. Lows around 70 near the shore to around 53 near 5000 feet. East winds up to 20 mph becoming 10 to 15 mph after midnight. Chance of rain 50 percent.

Lanai City

Tonight: Mostly cloudy with isolated showers early in the evening, then partly cloudy in the late evening and overnight. Lows 59 to 66. Northeast winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny in the morning then becoming mostly cloudy. Scattered showers. Highs 71 to 81. Light winds. Chance of rain 40 percent.

Saturday Night: Mostly clear. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows 59 to 67. Light winds becoming northeast up to 15 mph after midnight. Chance of rain 30 percent.

Kaunakakai

Tonight: Breezy. Mostly cloudy with scattered showers early in the evening, then partly cloudy in the late evening and overnight. Lows 56 to 72. East winds 10 to 20 mph. Chance of rain 50 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Scattered showers early in the morning. Isolated showers late in the morning, then scattered showers in the afternoon. Highs 70 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday Night: Partly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows 56 to 72. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Seasonably wet and breezy trades prevail into next week.

Discussion

High stability prevails in the mid-levels as a typical breezy trade wind pattern remains established over the area. An upper low of low- latitude origin sits over the area bringing a slight reduction in stability as the inversion on this morning's observed soundings was rather soft and not as sharp as normal. As a consequence, the band of showers advancing through the state today has had no issue maintaining showers around 10-12kft deep even during the unfavorable peak heating period. This is in turn enhancing leeward shower penetration, especially over Oahu, and contributing to pockets of heavier showers over windward/mauka portions of all islands.
The next 24-30 hours will be characterized by little overall change except for a subtle veering of the low level flow to a more ESE direction. Given adequate moisture availability in the boundary layer, this has caused several members of today's guidance suite to hint at potential for banding within convergent ESE flow (i.e. Molokai/Lanai plumes) both this afternoon and tomorrow afternoon. This type of setup generally remains highly uncertain until it is underway, though it tends to favor southern/central Oahu including the Honolulu area urban corridor. At present, a loosely organized plume of mostly light rain originating over leeward Molokai is indeed streaming over southern portions of Oahu. This band of rain will likely persist for the next few hours. Weak convergence observed within this band suggests limited prospects for strengthening.
Upper-level flow maintains a cyclonic character well into next week aiding slightly lowered stability and providing a boost to trade wind showers. As surface high pressure remains established north of the islands, a breezy and seasonably wet trade wind pattern is forecast to prevail for the next several days.

Aviation

A moderate to locally breezy trade wind pattern of mostly windward showers and passing low clouds will continue into early next week. Currently, scattered showers favor windward sides of the island chain. As winds turn more southeast, plumes of moisture will funnel additional showers across leeward areas during the afternoon and early evening hours. MVFR or even brief IFR ceilings and visibilities can be expected within any showers.
AIRMET Sierra remains in effect for mountain obscuration along windward sections across the island chain. These conditions will likely continue into the night.
AIRMET Tango remains in effect for low level moderate turbulence over and immediately S through W of all island mountains.

Marine

Strong high pressure will remain anchored northeast of the state through tonight, keeping fresh to strong trades in place. A developing trough to the distant northwest is expected to ease the trades over the weekend into early next week. Light to moderate trades with localized sea breezes are expected over the western islands, while moderate to locally strong persist over the eastern end of the state.
A Small Craft Advisory (SCA) remains in effect for most marine zones east of Oahu through 6 am Saturday, and for some of the windier zones around Maui and the Big Island through 6 pm Saturday. The SCA may need to be extended for the typically windy waters over the eastern end of the state through the weekend.
Surf along north and west-facing shores will remain very small during the next 7 days. Surf along south-facing shores will hold at background levels through tonight. A series of small south and south-southwest swells will give a small boost to south shore surf over the weekend, with a further boost up to the seasonal average possible during the middle to latter part of next week.
Surf along east-facing shores will hold close to seasonal normals during the next 7 days.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Saturday for Kaiwi Channel, Maui County Windward Waters.
Small Craft Advisory until 6 PM HST Saturday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov