Photo Credit: Jeni Ji Cousins

West Side

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 79 to 85. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows 63 to 69. East winds around 10 mph in the evening becoming light. Chance of rain 50 percent.

Wednesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 86. Light winds becoming south up to 10 mph in the afternoon. Chance of rain 40 percent.

South Side

Today: Breezy. Mostly sunny with isolated showers. Highs around 85. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 64. North winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Sunny. Highs around 86. Light winds becoming northwest 10 to 15 mph in the afternoon.

North Shore

Today: Breezy. Occasional showers in the morning, then showers likely in the afternoon. Highs 77 to 82 near the shore to around 63 near 5000 feet. East winds 10 to 20 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy. Showers likely early in the evening, then scattered showers late in the evening. Showers likely after midnight. Lows 61 to 67 near the shore to around 49 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Wednesday: Occasional showers in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to around 63 near 5000 feet. East winds 10 to 15 mph. Chance of rain near 100 percent.

Central Maui

Today: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 81 to 86. Northeast winds 15 to 20 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 62 to 67. Northeast winds around 10 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny. Isolated showers in the morning. Highs 82 to 87. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 57 at the visitor center to around 53 at the summit. Southeast winds around 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows around 45 at the visitor center to around 40 at the summit. Light winds. Chance of rain 50 percent.

Wednesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 58 at the visitor center to around 54 at the summit. East winds around 10 mph in the morning becoming light. Chance of rain 50 percent.

East Maui

Today: Breezy. Occasional showers in the morning, then showers likely in the afternoon. Highs 77 to 82 near the shore to around 63 near 5000 feet. East winds 10 to 20 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy. Showers likely early in the evening, then scattered showers late in the evening. Showers likely after midnight. Lows 61 to 67 near the shore to around 49 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Wednesday: Occasional showers in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to around 63 near 5000 feet. East winds 10 to 15 mph. Chance of rain near 100 percent.

Lanai City

Today: Breezy. Partly sunny with scattered showers in the morning, then sunny in the afternoon. Highs 72 to 79. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Tonight: Mostly clear. Lows around 65. Northeast winds around 10 mph in the evening becoming light.

Wednesday: Sunny. Isolated showers in the afternoon. Highs 72 to 79. Light winds. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 73 to 83. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows 58 to 70. Northeast winds around 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Mostly sunny. Isolated showers in the morning. Highs 75 to 85. East winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Clouds and showers associated with a dissipated front will continue to dampen windward areas from Maui to Kauai in the short term, producing low visibility and persistent rainfall. Breezy northeast trade winds over most of the state will gradually diminish over the next couple of days, with winds becoming light and variable by Friday. Windward showers will gradually diminish as winds weaken, but another front may bring increased showers next weekend.

Discussion

Low-level moisture associated with a dissipated front continues to advect (to varying degrees) into windward areas of the islands from Maui to Kauai while mostly dry conditions persist over the Big Island. Radar indicates that rainfall rates are relatively low with most of the showers, although there have been some localized moderate returns, while observers report briefly heavy downpours. Wettest windward rain gages have received over 7 inches of rainfall over the past 24 hours (i.e., Maunawili Oahu with 7.33″) , with widespread 2 to 4 inch rainfall totals. On the Big Island, mostly dry conditions are prevailing. Breezy NE winds exist on the N side of the boundary, with light NE to E winds over the Big Island. 12Z soundings show a subsidence inversion based near 9 thousand feet.
Model guidance is not consistent with the specifics regarding the movement and evolution of the low-level moisture pool over the next day or two, leading to decreased confidence in the details of the short-term cloud and shower forecast. Broadly speaking, it is expected to gradually dissipate as high pressure to the N moves away to the NE, with trade winds weakening and veering to the E by Wednesday. Windward showers should trend down as this occurs, with fewer showers for the second half of the week, with light to moderate trade winds prevailing. In the meantime, expect damp conditions to continue over windward areas from Kauai to Maui, with some sprinkles spreading leeward.
Meanwhile, satellite shows layered clouds and increased moisture over waters SE of the Big Island. Model guidance has trended toward a drier solution for windward and SE Big Island today, with the bulk of the moisture remaining offshore, thus PoPs have been lowered. Nonetheless, still expecting a few showers over the Big Island this afternoon and tonight.
A low developing NW of the islands will weaken and veer winds to the SE on Friday and Saturday, with light and variable winds likely allowing land/sea breezes to modulate island weather. An associated front may move over the island chain on Sunday, and the evolution of this feature is very unclear as models vary widely in the handling of a potential cutoff low to the W of the area.

Aviation

Remnant low level moisture from a dissipated front draped along the central islands will bring enhanced moisture to the windward portions of a Maui County and Oahu through mid morning. Periods of MVFR and IFR conditions, including low ceilings, 1000 to 2000 feet, and decreased visibility below a mile will likely accompany this activity. Isolated showers may occasionally push over the terrain and onto the leeward slopes. Mainly dry conditions will prevail on the Big Island. By this afternoon, however, typical moderate trades will bring a return of scattered showers to windward portions of all islands.
AIRMET SIERRA remains in effect through 15Z for periods of IFR conditions along north through east sections of Oahu, Molokai, and Maui due to tempo ceilings below 1000 feet and vis below 3SM in showers. Beyond 15Z, conditions may improve to MVFR for the aforementioned locations.
AIRMET TANGO remains in effect after for Kauai and Oahu due to tempo moderate turbulence between FL250 and FL380.

Marine

The large north northwest swell (340 degrees) that brought warning level surf has been steadily easing through the night based on latest near shore and offshore buoys. Thus the High Surf Warning has been downgraded to High Surf Advisory (HSA). The HSA for select west facing shores has been cancelled as the swell transitions to a more northerly direction. A HSA is now in effect for most north facing shores through today. There is a possibility the HSA may be extended due to another long period pulse out of the north reinforcing surf heights, but will continue to monitor latest guidance for now. In addition, a Small Craft Advisory is in effect for select coastal waters due to elevated seas from the large north swell through today. The proximity of this surf generation fetch introduces a wide spectrum of wave energy extending into the shorter periods, resulting in rough and choppy surf along north facing shores. A larger northwest (320 degrees) swell will build Thursday and continue through the weekend.
Surf along east facing shores will remain rough and choppy due to the combination of breezy trade winds and the north swell wrapping into exposed locations.
Overlapping, small, fading south swell and an incoming small, south- southwest swell will keep small surf along south facing shores for the next couple of days. The next small, long period south southwest swell is expected to fill in over the weekend.
A surface high north of the state is providing moderate to locally strong northeasterly trades early this morning. Trades are expected to become more easterly tonight out of the moderate to fresh range as the high tracks far northeast through Thursday. Winds may veer out of the southeast as early as Friday as a front approaches the state from the northwest.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST this evening for north facing shores of Niihau Kauai Oahu Molokai Maui and the Big Island.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Pailolo 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