Hilo

Today: Showers likely, mainly before noon. Partly sunny, with a high near 83. West wind 5 to 7 mph becoming east northeast in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 66. North wind 3 to 6 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Showers likely, mainly before noon. Mostly cloudy, with a high near 83. North northeast wind 6 to 9 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Isolated showers after noon. Mostly sunny, with a high near 79. Calm wind becoming west southwest 5 to 7 mph. Chance of precipitation is 20%.

Tonight: Scattered showers before midnight. Partly cloudy, with a low around 65. Calm wind becoming east around 5 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Isolated showers after noon. Mostly sunny, with a high near 79. Calm wind becoming northwest around 5 mph. Chance of precipitation is 20%.

Waimea

Today: Scattered showers, mainly after noon. Partly sunny, with a high near 78. Breezy, with a northeast wind 13 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before midnight. Mostly cloudy, with a low around 58. Breezy, with an east wind 13 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Scattered showers, mainly after noon. Partly sunny, with a high near 78. Breezy, with an east 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.

Kohala

Today: Showers likely. Mostly cloudy, with a high near 64. Breezy, with an east wind 20 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 53. Windy, with an east wind 22 to 26 mph, with gusts as high as 38 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Showers likely. Mostly cloudy, with a high near 64. Windy, with an east northeast wind 24 to 26 mph, with gusts as high as 38 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Sunny, with a high near 84. Windy, with an east wind 20 to 24 mph, with gusts as high as 31 mph.

Tonight: Mostly clear, with a low around 74. Breezy, with an east northeast wind 18 to 22 mph, with gusts as high as 28 mph.

Friday: Sunny, with a high near 84. Breezy, with an east wind 20 to 22 mph, with gusts as high as 28 mph.

Puna

Today: Showers likely, mainly before noon. Mostly cloudy, with a high near 82. Northwest wind 6 to 11 mph becoming northeast in the afternoon. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 64. North northeast wind around 11 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Friday: Showers likely, mainly before noon. Mostly cloudy, with a high near 82. Breezy, with a northeast wind 11 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Sunny, with a high near 84. Northeast wind 6 to 11 mph.

Tonight: Clear, with a low around 66. East northeast wind around 7 mph.

Friday: Sunny, with a high near 84. North northeast wind 6 to 8 mph.

Detailed Forecast

Synopsis

A surface high far northeast of the area will build southwest. Breezy easterly trade winds will persist through the Independence Day holiday weekend. Ridging aloft will keep the atmosphere dry and stable. The trade winds will carry clouds and some showers over windward areas, during mainly night and morning hours. Leeward areas of the smaller islands will be mostly dry. Clouds and showers will affect the Kona slopes of the Big Island during the afternoons and evenings.

Discussion

The global models continue to show a high far northeast of the main Hawaiian Islands building southwest over the next several days. Breezy trade winds will persist. Winds speeds will peak around Saturday when the high is directly north of the islands, then slowly drop as the high moves farther west.
Ridging aloft will produce subsiding air over the islands with a rather strong and low temperature inversion. The inversion will cap low level clouds and keep rainfall very light over most areas. The trade winds will push clouds and some showers over windward areas. These showers will be most active during the nights and early mornings. Leeward areas of the smaller islands will remain very dry. The trade winds will be blocked by the high terrain on the Big Island from reaching the Kona district, so afternoon clouds and showers will develop over the Kona slopes and persist into the evening hours.

Aviation

As high pressure strengthens from the northeast, trade winds will be on the increase across the area. A limited amount of showery low clouds, with accompanying MVFR conditions, will mainly affect windward and mauka sections across the island chain.
No AIRMETs are currently in effect, but AIRMET Tango may need to be issued later today as trade winds become more robust and the potential for low level turbulence S thru W of the mountain ranges increases.

Marine

Fresh to strong easterly trade winds will continue through the holiday weekend and early next week as high pressure builds to the north and the gradient remains tight over the region. The Small Craft Advisory in effect for the windier waters around the Big Island and Maui may need to be expanded to other areas late Friday through Saturday. Seas will become rough over the channels this weekend, likely nearing the 10 ft advisory threshold.
A south-southwest swell that filled in Wednesday will continue to generate near advisory-level surf (8 ft faces) today. Latest nearshore PacIOOS buoy readings reflect this early this morning holding within the 14-16 sec bands. A downward trend is expected Friday into the weekend.
The active trend will continue along south facing shores early next week as the largest swell of the season arrives. The archived surface analyses and satellite retrievals showed a large area of storm-force winds with seas estimated just above 40 ft within Hawaii’s swell window southeast of New Zealand as a 963 mb low passed through a few days ago. WAVEWATCH III has this source peaking at the Pago Pago PacIOOS buoy Friday night, which should correspond to a peak locally late Monday through Tuesday well above advisory levels. Forerunners should begin to move through Sunday night, then build all day Monday. This should be a long- lived event that holds through midweek before easing late next week.
Surf along exposed north and west facing shores will trend up Friday through Saturday as a small, northwest swell arrives from a gale centered near the Date Line over the Aleutian Islands (Typhoon Champi recurved and became absorbed into the Aleutian low). Otherwise, summertime conditions are anticipated.
Surf along east facing shores will slowly trend up and become rough over the weekend as the trades strengthen locally and upstream.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM Friday for Maalaea Bay, the Pailolo and Alenuihaha Channels and waters south of the Big Island.

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Data Courtesy of NOAA.gov