Photo Credit: Tyler Rooke

West Side

Today: Mostly cloudy. Scattered showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs 75 to 81. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Haze in the evening. Partly cloudy with scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows 65 to 71. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday: Breezy. Partly sunny with scattered showers and slight chance of thunderstorms in the morning, then mostly sunny with isolated showers in the afternoon. Locally heavy rainfall possible in the morning. Highs 75 to 81. Northeast winds 10 to 25 mph. Chance of rain 40 percent.

South Side

Today: Partly sunny. Isolated showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs around 84. North winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly clear. Haze in the evening. Slight chance of thunderstorms in the evening, then slight chance of thunderstorms and isolated showers after midnight. Locally heavy rainfall possible after midnight. Lows 63 to 74. North winds up to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Breezy. Slight chance of thunderstorms and isolated showers in the morning. Locally heavy rainfall possible in the morning. Highs around 84. North winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Chance of rain 20 percent.

North Shore

Today: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the morning, then numerous showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs 77 to 82 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Tonight: Haze in the evening. Mostly cloudy with numerous showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows around 67 near the shore to around 50 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Friday: Mostly cloudy. Breezy. Numerous showers and slight chance of thunderstorms in the morning, then numerous showers in the afternoon. Highs 76 to 81 near the shore to around 64 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Central Maui

Today: Mostly cloudy. Breezy. Isolated showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs around 82. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 40 percent.

Tonight: Breezy. Haze in the evening. Partly cloudy with slight chance of thunderstorms and isolated showers. Locally heavy rainfall possible. Lows 64 to 69. East winds 10 to 20 mph. Chance of rain 20 percent.

Friday: Breezy. Partly sunny with slight chance of thunderstorms and isolated showers in the morning, then mostly sunny with isolated showers in the afternoon. Locally heavy rainfall possible in the morning. Highs 79 to 85. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly cloudy. Scattered showers and chance of freezing rain in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs 55 to 68. East winds up to 15 mph. Chance of precipitation 50 percent.

Tonight: Breezy. Haze in the evening. Mostly cloudy with scattered showers and slight chance of thunderstorms in the evening, then partly cloudy with slight chance of thunderstorms and isolated showers after midnight. Locally heavy rainfall possible. Lows around 46 at the visitor center to around 41 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Partly sunny. Breezy. Isolated showers and slight chance of freezing rain in the morning, then scattered showers in the afternoon. Highs 55 to 67. East winds up to 20 mph. Chance of precipitation 50 percent.

East Maui

Today: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the morning, then numerous showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs 77 to 82 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Tonight: Haze in the evening. Mostly cloudy with numerous showers and slight chance of thunderstorms. Locally heavy rainfall possible. Lows around 67 near the shore to around 50 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Friday: Mostly cloudy. Breezy. Numerous showers and slight chance of thunderstorms in the morning, then numerous showers in the afternoon. Highs 76 to 81 near the shore to around 64 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Lanai City

Today: Partly sunny. Breezy. Isolated showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Haze through the day. Highs 71 to 78. Northeast winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the evening. Haze in the evening. Locally heavy rainfall possible in the evening. Lows around 63. Northeast winds 10 to 20 mph. Chance of rain 30 percent.

Friday: Mostly sunny. Breezy. Highs 71 to 78. Northeast winds 10 to 25 mph.

Kaunakakai

Today: Breezy. Mostly cloudy with scattered showers and slight chance of thunderstorms. Haze. Highs 68 to 84. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Haze in the evening. Slight chance of thunderstorms and isolated showers in the evening, then scattered showers and slight chance of thunderstorms after midnight. Locally heavy rainfall possible. Lows 56 to 72. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Friday: Mostly sunny. Breezy. Slight chance of thunderstorms and isolated showers in the morning. Locally heavy rainfall possible in the morning. Highs 67 to 85. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A weakening front over the Kauai Channel continues to produce showers mainly impacting Oahu. Lingering moisture combined with an upper disturbance moving over the state will increase rainfall chances statewide today through Friday, along with the chance for thunderstorms. As trade winds gradually return today, the focus of rainfall will shift to windward and mauka areas through early next week.

Discussion

The highest rainfall totals over the past 24 hours range from 1 to 2 inches over Oahu and from .20 to .75 inches over Kauai, as a diminishing stationary front remains between Kauai and Oahu early this morning based on a NE to SW oriented cloud band centered over the Kauai channel. Kauai radar remains down early this morning but the remaining radars and wind observations show showers have increased along windward and mauka areas across the state as winds continue to shift to a more east northeast direction. The morning soundings show the lower levels have moisten up around the Big Island with a dry layer around 9 kft while the Kauai sounding shows upper level temperatures have cooled, as an upper level trough digs south.
Forecast remain on track with the front weakening this morning and shifting westward as a high builds north of the state allowing for moderate to locally strong trades to return tonight into the weekend. The combination of enhanced moisture and increasing upper level instability may be enough to overcome the mid level drying and increase the risk of thunderstorms and locally heavy showers today into Friday. Latest high resolution models still favors the weakening frontal boundary as the area where the most activity will kick off, due to strengthening northeast and east southeast winds along the convergence boundary later this morning and early afternoon. Some elevated stream response is possible, especially for Kauai and Oahu as this boundary shifts from Oahu to Kauai, which may initiate a flood advisory or two. In addition, the Big Island summits may also see periods of wintry precipitation today through Friday.
Friday into early next week, bands of moisture moving with the trades along with lingering upper level instability from the trough cutting off and sagging south of the Big Island will keep enhanced rainfall chances mainly along windward and mauka areas with some showers spilling over to leeward areas at times. Chances for thunderstorms will trend down Friday night into Saturday as deep moisture is pushed west of the state and the upper low moves south of the state.

Aviation

Expect periods with MVFR conditions over the western end of the state persisting today due to a lingering cloud band associated with a diminishing frontal boundary stalled around Oahu. Showers will favor north- through east-facing slopes and coasts in these areas with light to moderate NE to E winds. Heavy showers and a few thunderstorms will be possible today through tonight as an upper disturbance dips south over the state. Another area of moisture moving into the Big Island will continue to support periods with MVFR CIGS/VSBYS.
AIRMET Sierra for mountain obscuration remains in effect for Oahu, Kauai, and the windward slopes of the Big Island.

Marine

Fresh to strong northeast trades will continue around Kauai today, on the northwest side of a weakening stationary front. Meanwhile, moderate to fresh trades will hold over the eastern most waters, and the waters around Oahu and Maui County will remain lighter. The front will have weakened into a trough by late this afternoon, and will begin to shift westward and gradually dampen out through Friday. This will allow for moderate to locally strong trades to fill in from east to west across the island chain. Moderate to locally strong trades should then hold in place through early next week, with only minor fluctuations in strength each day.
A Small Craft Advisory (SCA) is now in effect for all windward waters through 6 am Friday due to winds, seas, or a combination of the two. The SCA has been dropped for many leeward waters as seas have dropped below the 10 foot threshold.
The current extra-large northwest swell has peaked and will gradually decline through Saturday. A High Surf Warning remains in effect for most north and west facing shores through 6 PM this evening. Surf will likely hold at advisory levels for these same areas tonight, before dropping below the advisory threshold for Friday. A new long-period northwest swell will arrive late Saturday and Saturday night, peak Sunday into Sunday night, then lower Sunday night into Monday. This swell will give a boost to surf along north and west facing shores, but will likely remain below advisory levels. The next in the series of northwest swells will arrive early Monday, peak late Monday and Monday night, then gradually decline through the middle of next week. This swell may reach advisory levels as it peaks.
East shore surf not exposed to the series of northwest swells will remain will remain very small today, then gradually rise Friday through Saturday as the trades return over and upstream of the islands. Surf will then hold relatively steady along east facing shores through the middle of next week.
South shore surf will remain very small through the middle of next week.

Fire weather

No critical fire weather conditions are expected today into early next week as enhanced rainfall remains in the forecast.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 PM HST this evening for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala, Big Island South.
Small Craft Advisory until 6 AM HST Friday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters, Alenuihaha Channel, Big Island Windward Waters.

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov