West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 81 to 89. Northeast winds up to 20 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 70 to 78. Northeast winds 10 to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 81 to 88. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

South Side

Today: Sunny and breezy. Isolated showers in the afternoon. Highs around 91. North winds up to 20 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 68 to 79. Northeast winds 10 to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Scattered showers in the morning, then numerous showers in the afternoon. Highs around 90. North winds up to 20 mph. Chance of rain 60 percent.

North Shore

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs around 83 near the shore to around 70 near 5000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Breezy. Cloudy with showers. Lows around 72 near the shore to around 55 near 5000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Thursday: Mostly cloudy. Breezy. Numerous showers in the morning, then showers in the afternoon. Highs 80 to 85 near the shore to around 69 near 5000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Central Maui

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 83 to 91. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then scattered showers after midnight. Lows 68 to 75. Northeast winds 15 to 20 mph. Chance of rain 70 percent.

Thursday: Mostly cloudy. Breezy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 83 to 90. Northeast winds 10 to 25 mph. Chance of rain 70 percent.

Upcountry

Today: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs around 68 at the visitor center to around 72 at the summit. Northeast winds up to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 53 at the visitor center to around 51 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Thursday: Mostly cloudy. Breezy. Scattered showers in the morning, then showers in the afternoon. Highs around 68 at the visitor center to around 71 at the summit. East winds up to 20 mph. Chance of rain 90 percent.

East Maui

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs around 83 near the shore to around 70 near 5000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Breezy. Cloudy with showers. Lows around 72 near the shore to around 55 near 5000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Thursday: Mostly cloudy. Breezy. Numerous showers in the morning, then showers in the afternoon. Highs 80 to 85 near the shore to around 69 near 5000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Lanai City

Today: Sunny and windy. Isolated showers in the afternoon. Highs 75 to 84. Northeast winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Windy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 69. Northeast winds 20 to 30 mph. Chance of rain 40 percent.

Thursday: Windy. Mostly sunny in the morning, then mostly cloudy with numerous showers in the afternoon. Highs 75 to 84. Northeast winds up to 30 mph decreasing to up to 20 mph in the afternoon. Chance of rain 70 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 72 to 90. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 61 to 76. Northeast winds 10 to 25 mph. Chance of rain 50 percent.

Thursday: Breezy. Mostly sunny with scattered showers in the morning, then mostly cloudy with numerous showers in the afternoon. Highs 72 to 90. Northeast winds 10 to 25 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Breezy trades expected through the forecast period. Moisture will continue to fill in across the state from east to west into Friday increasing chances of showers mainly for windward and mauka areas. Chances of heavy rain, isolated thunderstorms and flood potential will increase Thursday into Friday as an upper level disturbance moves overhead. Drier air will move back in this weekend as trades continue. Moisture from the remnants of Tropical Depression 15-E may bring another round of enhanced trade showers early next week.

Discussion

Radar and satellite imagery shows some scattered showers over windward and mauka locations across the state. Moderate trades were observed across the state. Moderate trades will increase today into the breezy levels.
An upper level trough will sink down over the state today and tonight just as the deepest surge of moisture from remnants of Norbert begin to move across the state. This will result in a sharp increase in moderate to heavy showers late tonight through early Friday. Instability will be sufficient for an isolated thunderstorm as well.
Moisture will decrease late Friday through the weekend. Latest guidance shows another area of increasing moisture (from the remnants of tropical depression 15-E) moving into the area Monday or Tuesday next week. The GFS shows better upper level support that could enhance the trade showers while ECMWF shows mid level ridging that could help limit heavy shower potential. Will continue to monitor all available guidance to determine exact impacts with future updates.

Aviation

Moderate to locally breezy trade winds will strengthen to breezy levels this afternoon and a trough will approach the area from the east. Showers and low clouds associated with that trough will increase with the trade wind flow from east to west starting early tonight for the eastern half of the state, then spread west late tonight into tomorrow morning. More widespread MVFR conditions will be possible as the moisture associated with the trough moves in, especially for windward and mountain areas.
No AIRMETs are currently in effect. There is the possibility for AIRMET Tango during the afternoon once trade winds strengthen.

Marine

A building ridge to the north of the Hawaiian Islands and broad low pressure south of the islands leads trades to increase to fresh to locally strong today. A Small Craft Advisory has been issued for the typically windy waters around the Big Island and Maui County through tonight. Locally strong winds may briefly diminish tonight into Thursday, but look to return later this week and last into the weekend. The remnants of Tropical Storm Norbert in combination with another weak low pressure to the south will bring isolated thunderstorms to area waters this afternoon through Saturday.
A series of long-period south to southwest swells will fill in through the rest of the week, leading to a gradual increase in surf for south-facing shores through the weekend. Surf is initially small today, but will trend upward toward the High Surf Advisory threshold by this weekend. Surf along east-facing shores increases today into Thursday as trade winds strengthen and a small, medium-period east swell from the remnants of Tropical Storm Norbert arrives. Flat to tiny surf along north facing shores is expected through the forecast period.

Fire weather

Fire weather risk should remain low through the remainder of the week due to moderate to breezy winds and increased relative humidity and moisture from the remnants of Norbert. Showers will dramatically increase late tonight through early Friday. Inversion heights will be around 7,500 to 8,500 ft.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Thursday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov