Hilo

This Afternoon: Scattered showers. Mostly cloudy, with a high near 77. East wind around 9 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Frequent showers, mainly after 8pm. Low around 62. East wind 5 to 9 mph becoming light and variable. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Frequent showers. High near 76. East southeast wind 5 to 7 mph becoming calm in the afternoon. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Kona

This Afternoon: Scattered showers. Widespread haze. Mostly cloudy, with a steady temperature around 73. Southwest wind around 5 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before 8pm. Widespread haze before 8pm, then widespread haze after midnight. Mostly cloudy, with a low around 60. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers after 11am. Widespread haze. Partly sunny, with a high near 79. Light and variable wind becoming west northwest 5 to 8 mph in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

This Afternoon: Isolated showers. Widespread haze. Mostly cloudy, with a steady temperature around 66. Breezy, with a northeast wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.

Tonight: Scattered showers, mainly after 8pm. Widespread haze before 8pm, then widespread haze after midnight. Mostly cloudy, with a low around 51. Breezy, with a northeast wind around 16 mph, with gusts as high as 22 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Widespread haze. Mostly cloudy, with a high near 74. Windy, with a northeast wind 11 to 16 mph increasing to 18 to 23 mph in the afternoon. Winds could gust as high as 32 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Kohala

This Afternoon: Scattered showers. Mostly cloudy, with a steady temperature around 61. Windy, with an east northeast wind around 30 mph, with gusts as high as 44 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after 8pm. Mostly cloudy, with a low around 44. Windy, with an east northeast wind around 30 mph, with gusts as high as 44 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Showers likely, mainly before 11am. Cloudy, with a high near 70. Windy, with an east northeast wind 24 to 30 mph, with gusts as high as 44 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

This Afternoon: Widespread haze. Mostly sunny, with a high near 79. Windy, with an east northeast wind around 30 mph, with gusts as high as 39 mph.

Tonight: Scattered showers after midnight. Widespread haze before 8pm, then widespread haze after midnight. Partly cloudy, with a low around 68. Windy, with an east northeast wind 26 to 30 mph, with gusts as high as 39 mph. Chance of precipitation is 30%.

Thursday: Scattered showers, mainly before 11am. Widespread haze. Partly sunny, with a high near 79. Windy, with an east northeast wind 28 to 30 mph, with gusts as high as 39 mph. Chance of precipitation is 30%.

Puna

This Afternoon: Scattered showers. Mostly cloudy, with a high near 76. East wind around 11 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Frequent showers, mainly after 8pm. Low around 60. East wind 6 to 11 mph becoming north northwest after midnight. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

Thursday: Frequent showers, mainly before 11am. High near 75. North northwest wind 6 to 10 mph becoming east northeast in the afternoon. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Waikoloa

This Afternoon: Isolated showers. Widespread haze. Mostly cloudy, with a steady temperature around 73. North wind around 5 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before 8pm. Widespread haze before 8pm, then widespread haze after midnight. Mostly cloudy, then gradually becoming mostly clear, with a low around 60. North wind 5 to 10 mph becoming east southeast after midnight. Chance of precipitation is 20%.

Thursday: Isolated showers after 11am. Widespread haze. Mostly sunny, with a high near 80. East southeast wind 6 to 14 mph becoming west northwest in the morning. Winds could gust as high as 18 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Breezy to locally strong easterly trade winds will prevail through the weekend, with clouds and showers favoring windward and mountain locations. A modest increase in moisture moving in from the east combined with an upper disturbance may lead to better windward shower coverage Thursday night through the weekend. A return of drier trade wind conditions will be possible early next week.

Discussion

Breezy to locally strong trade winds will continue through the weekend in response to strong high pressure (1040-1050 mb) far northeast of the state. Clouds and showers will favor windward and mountain locations, especially through the overnight and early morning periods. Lowering upper heights combined with a slight increase in moisture shifting into the area from the east will support better windward shower coverage Thursday night through the weekend. Although confidence remains low, this added instability and better moisture source could trigger a thunderstorm or two over the Big Island Friday into the weekend – mainly through the afternoon periods across the leeward Big Island slopes. For the smaller islands, expect some showers to spill over into leeward locations due to a combination of the strong trades and the trade wind inversion rising. A more typical trade wind pattern will be possible beginning early next week, as drier air arrives from the east.

Aviation

MVFR clouds that were present this morning have lifted early this afternoon as locally strong easterly trade winds have allowed isolated showers to favor east facing slopes and coasts of the islands. These locally strong winds will continue tonight and into the day tomorrow as the surface high northeast of the state strengthens. Clouds and showers will continue to favor eastern sections of the islands throughout the period. Some MVFR conditions and mountain obscuration will be possible during the early morning hours, particularly for the Big Island.
AIRMET Tango remains in effect for low level mechanical turbulence for areas over and immediately south through west of mountains due to the locally strong trade winds. Given the persistence of the strong winds, the threat of low level mechanical turbulence is likely to persist throughout the forecast period. Occasional low- level wind shear may also be possible for some airports, but confidence remains too low to include in the TAFs at this time.

Marine

Strengthening high pressure northeast of the state will produce strong- to near gale-force easterly trade winds across most of the Hawaiian waters. The exception will be over the Alenuihaha Channel, where gales are expected through Thursday. Thus,a Gale Warning remains in effect for the Alenuihaha Channel through Thursday afternoon. A Small Craft Advisory is in effect for rest of the coastal waters due to a combination of strong trades and elevated seas. Strong trades and elevated seas will likely continue through the weekend as another strong high builds far north of the state on Sunday.
Strong trade winds over and upstream of the islands will keep advisory level surf in place along east facing shores through the first half of next week. A High Surf Advisory (HSA) is in effect for east facing shores of Kauai, Oahu, Molokai, Maui and the Big Island through 6 AM Monday morning. An uptick in surf is expected over the next few days as the winds increase locally and upstream of the state.
A series of small overlapping northwest swells will move through the area into next week, with surf remaining below advisory levels along exposed north and west facing shores. The first of the series of northwest swells is expected late Thursday followed by another reinforcing northwest swell late Saturday into Sunday.
Wrapping trade wind swell continues to provide some small surf along south facing shores. A small out of season south swell will give a boost to south shore surf late Thursday through Saturday.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Monday for Kauai Windward, Oahu Koolau, Olomana, Molokai Windward, Maui Windward West, Windward Haleakala, South Big Island, Big Island North and East.
Wind Advisory until 6 PM HST Thursday for Molokai, Kahoolawe, Maui Windward West, Maui Leeward West, Maui Central Valley, Windward Haleakala, Leeward Haleakala, South Big Island, Big Island North and East, Kohala, Big Island Interior.
Small Craft Advisory until 6 AM HST Friday 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 PM HST Thursday for Alenuihaha Channel.