West Side

Today: Windy. Mostly cloudy with scattered showers. Highs 76 to 82. Northeast winds 15 to 30 mph. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows 67 to 74. Northeast winds 10 to 30 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 82. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

South Side

Today: Windy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 85. Northeast winds 20 to 30 mph. Chance of rain 50 percent.

Tonight: Windy. Partly cloudy with isolated showers. Lows 68 to 75. North winds 25 to 30 mph decreasing to 10 to 30 mph after midnight. Chance of rain 20 percent.

Thursday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 85. North winds 10 to 20 mph. Chance of rain 20 percent.

North Shore

Today: Breezy and showers. Highs around 81 near the shore to around 62 near 5000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain near 100 percent.

Tonight: Breezy and showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 15 to 25 mph. Chance of rain near 100 percent.

Thursday: Breezy. Cloudy with showers. Highs around 80 near the shore to around 62 near 5000 feet. East winds 15 to 25 mph. Chance of rain 90 percent.

Central Maui

Today: Mostly cloudy. Windy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 79 to 84. Northeast winds 15 to 30 mph. Chance of rain 70 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows around 70. Northeast winds 15 to 30 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 79 to 84. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Upcountry

Today: Partly sunny. Windy. Showers in the morning, then scattered showers in the afternoon. Highs around 58 at the visitor center to around 65 at the summit. East winds 10 to 35 mph with gusts to 55 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Windy. Showers in the evening, then scattered showers after midnight. Lows around 47 at the visitor center to around 43 at the summit. East winds 25 to 30 mph. Chance of rain 90 percent.

Thursday: Windy. Partly sunny with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 57 at the visitor center to around 65 at the summit. East winds 20 to 30 mph. Chance of rain 70 percent.

East Maui

Today: Breezy and showers. Highs around 81 near the shore to around 62 near 5000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain near 100 percent.

Tonight: Breezy and showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 15 to 25 mph. Chance of rain near 100 percent.

Thursday: Breezy. Cloudy with showers. Highs around 80 near the shore to around 62 near 5000 feet. East winds 15 to 25 mph. Chance of rain 90 percent.

Lanai City

Today: Windy. Partly sunny with scattered showers. Highs 70 to 79. Northeast winds 20 to 30 mph with gusts to 50 mph. Chance of rain 40 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows around 66. Northeast winds 15 to 30 mph. Chance of rain 50 percent.

Thursday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 71 to 80. East winds 10 to 25 mph. Chance of rain 20 percent.

Kaunakakai

Today: Windy. Partly sunny with scattered showers. Highs 68 to 86. Northeast winds 20 to 30 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 58 to 74. East winds 20 to 25 mph. Chance of rain 50 percent.

Thursday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 69 to 86. East winds 20 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A broad high dominating much of the Central Pacific will maintain breezy to windy trades across the Hawaiian Islands through Thursday morning. Enhanced shower activity and cloud coverage will persist predominately over windward and mauka areas. Trades will begin to weaken to a more moderate regime by Friday in response to the high weakening and propagating northeastward away from the Hawaiian Islands.

Discussion

The latest surface analysis depicts a broad 1035 mb area of high pressure well north of the Hawaiian Islands, maintaining breezy to locally windy trades through early Thursday morning. A Wind Advisory has been issued for portions of Maui County and Big Island through 6 AM Thursday as a result. As the aforementioned high continues to build, the pressure gradient tightens across the state, and may cause more widespread and persistent winds to exceed advisory thresholds briefly beyond the typical wind-prone locations. The strongest winds are expected to continue through tonight, then slowly weaken and become moderate to breezy by the latter end of the week as the area of high pressure meanders northeastward away from the islands.
As the week progresses, the enhanced trades will bring periods of shower activity, particularly across windward and mauka areas. Guidance continues to show an uptick in shower activity for today as an area of moisture associated with a dissipating front gets embedded in the trade wind flow, with much of the moisture aimed at Maui and the Big Island. However, the latest model total precipitable water (PWAT) normalized anomaly from the GFS and ECWMF has seemingly toned down what was previously depicted 24 hours ago, highlighting PWAT values are closer to 0 to 1 standard deviations above normal now. Despite this, expect windward trade showers to be preeminent throughout the week, then gradually lessen heading into the weekend.
Fall is in the air as a slightly drier air mass will keep dew points mainly in the mid 60s, keeping the islands cooler than average for the week. A few hours of lower relative humidity is also once again possible late this morning as satellite observations show a transient dry slot moving northeast to southwest toward the state. This should be short- lived, especially as the low- level moisture embedded in the trades moves in shortly thereafter by this afternoon. Additional areas of moisture should help to keep relative humidity values elevated through the remainder of the week.
Some model guidance begins to depict a surface trough producing southerly flow propagate over the islands escorting an abundance of moisture from the tropics with it around Monday or Tuesday of next week. Latest model guidance of the ECMWF and Canadian retains the tropical moisture south of the islands. The GFS, on the other hand, suggests ample moisture will be pulled northward into the islands and leading to a potential heavy rainfall event. The GFS also showcases a prolific cold front advancing southward during the same time, which is not illustrated on the ECMWF or Canadian. There's still a fair bit of uncertainty, however, namely given the long lead time before the event, and further analysis on model trends will be required to determine how accurate this initial assessment proves to be.

Aviation

Broad surface high pressure north of the island will lead to breezy to locally windy trades persisting through Thursday morning. Clouds and shower activity associated with these trades will bring periods of MVFR/IFR conditions to windward and mauka areas. Otherwise VFR conditions prevail.
AIRMET Sierra continues for mountain obscuration across all islands.
AIRMET Tango will continue for mechanical turbulence over and downwind of terrain below 8,000 feet
Both AIRMETs will likely remain in effect into Thursday.

Marine

A strong 1034 mb surface high, centered around 1000 nm north of the islands, will help drive fresh to locally gale force trade winds across Hawaiian waters this morning. The high will slowly drift slowly southeast through tonight and maintain robust east northeasterly flow. The strong trade winds, combined with building northeast and northwest swells, will also result in seas greater than 10 feet across the area. A Gale Warning remains in effect through Thursday morning for the Alenuihaha Channel, where flow funneling around the terrain of Maui and the Big Island will accelerate trades even more. Elsewhere, a Small Craft Advisory (SCA) remains in effect for a combination of winds and seas. The aforementioned high to our north will gradually drift eastward and weaken Friday into this weekend, allowing winds to weaken to moderate to locally strong through this weekend.
The current short period northeasterly swell will produce large breaking waves along east facing shores through Thursday afternoon. A combination of higher than predicted water levels, large breaking waves, and strong onshore winds could lead to significant wave runup, beach erosion, and localized coastal flooding for east facing shores during daily peak high tide cycle. Thus, a High Surf Advisory remains in effect for east facing shores through 6 PM HST Thursday. Northeast swell energy and associated surf should decline late Thursday through this weekend as local trade winds weaken.
A small to moderate, long period, northwest swell will peak later today and keep surf along north and some west facing shores elevated, but below advisory levels. This swell energy should fade through Friday. Another small, long period, northwest swell is progged to enter the local waters this weekend, which will again bring a sub advisory level bump up of surf along north facing beaches.
A small, long period, south swell will peak this morning and generate surf near or slightly above the November average, then fade through the remainder of the week.

Fire weather

Breezy to windy trades will continue through early Thursday, becoming moderate to breezy before the weekend. A few hours of near critical fire weather conditions are possible late this morning as relative humidity may briefly fall into the mid to upper 40s due to a transient dry slot moving across the state. However, this should be short-lived as low-level moisture embedded in the trades quickly fills in behind. Additional areas of moisture moving into the state should help to keep relative humidity from reaching critical thresholds for the remainder of the week. Temperature inversion heights near the Big Island and Maui will range from 9,000 to 10,000 feet today.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Thursday for Olomana, Maui Windward West, Kauai East, East Honolulu, Koolau Windward, Molokai Windward, Molokai Southeast, Windward Haleakala, Kipahulu, Big Island East, Big Island North.
Wind Advisory until 6 AM HST Thursday for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Kohala, Big Island Interior, Lanai Windward, Lanai Leeward, Maui Central Valley North, Maui Central Valley South, South Haleakala, Big Island Southeast, Big Island North.
Small Craft Advisory until 6 PM HST Thursday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.
Gale Warning until 6 AM HST Thursday for Alenuihaha Channel.

Data Courtesy of NOAA.gov