Hilo

Today: Scattered showers, mainly before noon. Mostly sunny, with a high near 76. Northeast wind 5 to 7 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Occasional showers, mainly after midnight. Low around 60. North northeast wind around 5 mph becoming west southwest in the evening. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Mostly cloudy, with a high near 75. West southwest wind 5 to 8 mph becoming northeast in the morning. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Isolated showers after noon. Mostly sunny, with a high near 78. West wind around 7 mph becoming south southwest in the afternoon. Chance of precipitation is 20%.

Tonight: Scattered showers, mainly before midnight. Partly cloudy, with a low around 58. South southwest wind 5 to 7 mph becoming light and variable after midnight. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers after noon. Mostly cloudy, with a high near 77. Southwest wind 5 to 8 mph becoming calm in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers, mainly before noon. Mostly sunny, with a high near 73. Breezy, with a northeast wind around 18 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Partly cloudy, with a low around 49. Breezy, with a northeast wind 13 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Thursday: Scattered showers. Mostly cloudy, with a high near 72. Breezy, with a northeast wind 10 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Scattered showers. Mostly sunny, with a temperature falling to around 60 by 5pm. Breezy, with an east northeast wind around 22 mph, with gusts as high as 31 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after midnight. Partly cloudy, with a low around 42. Windy, with an east wind 18 to 23 mph, with gusts as high as 33 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Mostly cloudy, with a high near 68. Breezy, with an east northeast wind 11 to 20 mph, with gusts as high as 26 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Sunny, with a high near 78. Windy, with an east wind 22 to 25 mph, with gusts as high as 32 mph.

Tonight: Isolated showers. Partly cloudy, with a low around 66. Windy, with an east wind 18 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Thursday: Isolated showers after noon. Mostly cloudy, with a high near 77. Windy, with an east northeast wind 17 to 23 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

Puna

Today: Showers likely, mainly before noon. Mostly sunny, with a high near 75. North northeast wind around 10 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Occasional showers, mainly after midnight. Low around 58. North northeast wind 6 to 9 mph becoming west northwest in the evening. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

Thursday: Scattered showers. Mostly cloudy, with a high near 74. West northwest wind 7 to 9 mph becoming north northeast in the afternoon. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Waikoloa

Today: Sunny, with a high near 79. Breezy, with a northeast wind 20 to 22 mph, with gusts as high as 31 mph.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 58. Breezy, with an east wind 11 to 20 mph, with gusts as high as 26 mph. Chance of precipitation is 20%.

Thursday: Isolated showers after noon. Partly sunny, with a high near 78. Breezy, with an east wind 12 to 17 mph becoming east northeast 5 to 10 mph in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Breezy trade winds will continue for the next few days as high pressures lies far to our north. Winds will strengthen over the weekend and on into early next week as the high to our north strengthens. An upper trough will linger over the area throughout the forecast period. Clouds and passing showers will favor windward and mauka areas with the trade winds sufficiently strong enough to blow some passing showers over to leeward areas at times.

Discussion

Strong high pressure is centered far to the north northeast of the state resulting in breezy to locally wind trade winds across the area. Moisture embedded in the trades is currently producing some showers of Kauai and portions of the Big Island while the Oahu and Maui County are mainly dry. Meanwhile, a weak upper trough lies over the area. This is allowing for some of the showers to be briefly moderate in intensity. There will likely be a slight uptick in shower activity across the central islands later today as an area of moisture seen on satellite imagery interacts with island terrain.
The high is forecast to drift east southeast and weaken slightly over the next few days. Also a weak low level trough will set up in the island vicinity. This will allow for a slight downward trend in trade wind speeds. Meanwhile, the weak upper trough will linger over the area. This will keep the airmass a bit less stable which will allow for a continuation of passing showers especially for windward and mauka areas. Also, guidance there will be in increase in high level clouds over the area which may dim the sun from time to time.
By Friday night and on into Saturday, the remnants of an old front will move into the area from the northeast. This will result in an overall uptick in shower activity over the weekend and on into early next week. The surface high will then strengthen north of the state with trade winds speeds increasing once again to breezy and windy levels. The upper trough will continue to linger over the area on into early next week keeping the airmass on the unstable side.

Aviation

A surface high to the northwest of the state will continue to support breezy to locally strong easterly trade winds today, but speeds will slowly lower through Thursday. AIRMET Tango remains in effect for moderate low-level turbulence near and downwind of mountains. AIRMET Tango will also remain in effect, likely through today, for moderate mid-level turbulence between FL220 and FL300, due to a strong jet stream over the state.
Otherwise, showers will continue to ride in on the trade wind flow and impact mainly windward coasts and slopes, though most showers should remain light with only brief periods of MVFR ceilings/visibility.

Marine

A high far northwest of the area will slowly weaken and move southeast before stalling north of the area tomorrow afternoon. A Small Craft Advisory (SCA) is in effect for all waters through this afternoon due to a combination of strong trade winds and elevated seas. The SCA may be extended or scaled back tonight as winds and seas slowly ease with the weakening high. The high will maintain SCA level trade winds and seas over northwest waters through tomorrow. SCA conditions may return for most waters Friday due to building seas, and extend over the weekend as the high is reinforced and strong trades become more widespread.
Trade winds swell will maintain east shoreline surf at or above the 8 foot High Surf Advisory (HSA) threshold through this afternoon. As trade winds over and upstream of the islands weaken, surf along east facing shores will slowly decline and become small by tomorrow. A bump in east shoreline surf will occur late Friday night into the weekend as trade wind swell increases and an arriving north swell wrap fills in.
A northwest swell will begin arriving this late this afternoon and evening, peaking at or just below HSA along north and west- facing shores late Thursday into Friday. The secondary, reinforcing north swell will arrive Friday night and, in addition to the returning trade wind swell wrap, may boost north facing shore surf heights to, or slightly above, HSA heights Friday into Saturday and slowly diminish Sunday.
Surf along south-facing shores has declined since yesterday due to the declining easterly trade wind swell. A small, long- period southwest swell will fill in tomorrow, providing a small bump in south shore surf, and slowly decline through the weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST this evening 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 this evening for all Hawaiian waters,