Hilo

Today: Frequent showers, mainly before 1pm. High near 77. Light and variable wind becoming east 5 to 9 mph in the morning. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Frequent showers, mainly after 7pm. Low around 62. East southeast wind around 5 mph becoming south southwest after midnight. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Frequent showers. High near 76. South southwest wind around 5 mph becoming light and variable. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Widespread haze. Mostly sunny, with a high near 79. Calm wind becoming west northwest 5 to 9 mph in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before midnight. Widespread haze. Partly cloudy, with a low around 60. Northwest wind around 5 mph becoming east northeast in the evening. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers, mainly after noon. Widespread haze. Mostly sunny, with a high near 79. South southeast wind 6 to 8 mph becoming north northwest in the morning. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Waimea

Today: Scattered showers. Widespread haze. Partly sunny, with a high near 74. Windy, with a northeast wind 15 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.

Tonight: Scattered showers. Widespread haze. Mostly cloudy, with a low around 51. Windy, with an east wind 21 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 50%. New precipitation amounts between a quarter and half of an inch possible.

Thursday: Showers likely, mainly after noon. Widespread haze. Partly sunny, with a high near 74. Windy, with an east wind 21 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

Kohala

Today: Frequent showers. High near 70. Windy, with an east wind 23 to 29 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Frequent showers. Low around 44. Windy, with an east wind 20 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Frequent showers. High near 70. Windy, with an east wind 21 to 24 mph, with gusts as high as 34 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Isolated showers. Widespread haze. Mostly sunny, with a high near 79. Windy, with an east northeast wind around 29 mph, with gusts as high as 37 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Widespread haze. Partly cloudy, with a low around 68. Windy, with an east northeast wind 26 to 28 mph, with gusts as high as 36 mph. Chance of precipitation is 20%.

Thursday: Isolated showers. Widespread haze. Mostly sunny, with a high near 79. Windy, with an east northeast wind around 29 mph, with gusts as high as 37 mph. Chance of precipitation is 20%.

Puna

Today: Frequent showers, mainly before noon. High near 76. Northeast wind 6 to 13 mph becoming north northwest in the morning. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Frequent showers. Low around 60. North northeast wind 7 to 10 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

Thursday: Frequent showers. High near 75. Northeast wind 7 to 10 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

Waikoloa

Today: Isolated showers after noon. Widespread haze. Mostly sunny, with a high near 80. Breezy, with an east wind 10 to 15 mph becoming north in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Widespread haze. Mostly clear, with a low around 60. Breezy, with an east wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.

Thursday: Isolated showers after noon. Widespread haze. Mostly sunny, with a high near 80. Breezy, with a north northeast wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

High pressure north and northeast of the islands will keep breezy to windy trades in place through the weekend. Drier trade wind weather is expected through late Wednesday. Upper level troughing, along with an influx of moisture from the east, will likely increase shower coverage and intensity Thursday through the weekend.

Discussion

A high far northeast of the main Hawaiian Islands is driving fresh to strong trade winds across local waters this evening, while a trough sits about 600 miles west of Kauai. Satellite loop shows broken to overcast low clouds across most windward areas as well as across upper slopes of Kona district of the Big Island. Overcast layered clouds along the eastern flank of an upper trough to the west of the island chain are beginning to drift eastward across Kauai. Radar shows light to moderate showers drifting across Kauai and across windward portions of Maui and the Big Island. Showers will taper off tonight before the next cloud band moves in by the trades late Wednesday.
The high northeast of the state will strengthen Wednesday night, boosting wind speeds through Friday night. Troughing northwest of the state will then cause winds to decrease again this weekend. Daytime wind speeds will likely be at or just below advisory levels in exposed areas over the next few days.
A broad upper trough will develop across the islands and persist into this weekend. This will raise the inversion and enhance trade wind showers. An elevated inversion will limit strong downsloping wind gusts. Showers will continue to favor windward and mauka areas. We will consider the possibility of thunderstorms as time gets closer.

Aviation

The primary aviation hazard during the forecast period will be breezy to locally strong trades, including an increased threat for a localized wind shear hazard at susceptible locations. Additional slight strengthening of the trades is expected during the forecast period. In the near term, Windward Maui through Big Island will experience frequent reductions to MVFR as showers expand in coverage and stream onshore. As a result, AIRMET Sierra for mountain obscuration has been issued for those locations. Prevailing VFR is forecast elsewhere.
AIRMET Tango remains in effect for lee turbulence for the entire area.

Marine

Strong high pressure north and northeast of the islands will keep strong to near gale force easterly trade winds blowing through early next week.
A combination of strong trade winds and elevated seas will produce Small Craft Advisory conditions across most coastal waters at least through the weekend, and possibly into the first half of next week. A Gale Watch remains in effect for the Alenuihaha Channel starting on Wednesday morning as trade wind speeds are forecast to strengthen.
Strong trade winds will produce elevated surf along east facing shores through the first half of next week. A High Surf Advisory (HSA) remains in effect for east facing shores of Kauai, Oahu, Molokai, Maui and the Big Island through 6 AM Saturday. This HSA will likely need to be extended into early next week.
A series of small overlapping northwest swells will move through the area through the weekend. Surf heights along exposed north and west facing shores will remain below HSA thresholds through early next week.
A small out of season south swell will give a boost to south shore surf late Thursday through early Saturday. Otherwise, surf along south facing shores will remain small through early next week.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Saturday for Kauai Windward, Oahu Koolau, Olomana, Molokai Windward, Maui Windward West, Windward Haleakala, South Big Island, Big Island North and East.
Small Craft Advisory until 6 PM HST Wednesday for Kauai Northwest Waters, Kauai Windward 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 Watch from Wednesday morning through Wednesday afternoon for Alenuihaha Channel.
Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha Channel.

Data Courtesy of NOAA.gov