Hilo

Today: Showers likely, mainly before noon. Mostly cloudy, with a high near 81. West wind 5 to 10 mph becoming north northeast in the morning. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Cloudy, with a low around 65. North wind 5 to 9 mph becoming west southwest after midnight. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Showers likely, mainly before noon. Mostly cloudy, with a high near 80. West southwest wind 5 to 14 mph becoming north northeast in the afternoon. Winds could gust as high as 18 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Partly sunny, with a high near 78. West 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.

Tonight: Scattered showers before midnight. Mostly cloudy, with a low around 64. Calm wind becoming east southeast around 6 mph after midnight. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Scattered showers after noon. Partly sunny, with a high near 79. East wind around 5 mph becoming west northwest 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 cloudy, with a high near 71. Windy, with a northeast wind 20 to 25 mph, with gusts as high as 36 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 55. Windy, with an east northeast wind 20 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday: Scattered showers. Partly sunny, with a high near 71. Breezy, with a northeast wind 14 to 20 mph, with gusts as high as 28 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Showers likely, mainly before noon. Cloudy, with a high near 66. Windy, with an east northeast wind 22 to 25 mph, with gusts as high as 36 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Cloudy, with a low around 54. Windy, with an east northeast wind around 23 mph, with gusts as high as 32 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: Showers likely. Mostly cloudy, with a high near 66. Windy, with an east northeast wind 16 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Mostly sunny, with a high near 79. Windy, with an east wind 24 to 28 mph, with gusts as high as 36 mph.

Tonight: Partly cloudy, with a low around 72. Windy, with an east northeast wind 23 to 25 mph, with gusts as high as 32 mph.

Saturday: Isolated showers after noon. Mostly sunny, with a high near 79. Windy, with an east northeast wind 22 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Puna

Today: Showers likely, mainly before noon. Cloudy, with a high near 78. Breezy, with a northwest wind 8 to 16 mph becoming north northeast in the afternoon. Winds could gust as high as 22 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Showers likely. Cloudy, with a low around 62. North northwest wind 8 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday: Showers likely, mainly before noon. Mostly cloudy, with a high near 77. Breezy, with a north northeast wind 8 to 18 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Mostly sunny, with a high near 81. Windy, with an east northeast wind 17 to 22 mph increasing to 23 to 28 mph in the morning. Winds could gust as high as 40 mph.

Tonight: Mostly clear, with a low around 65. Windy, with an east wind 17 to 25 mph, with gusts as high as 36 mph.

Saturday: Isolated showers after noon. Mostly sunny, with a high near 82. Breezy, with a north northeast wind 9 to 17 mph, with gusts as high as 24 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Breezy northeast trade winds will continue through the weekend, then shift out of the east early next week. Showers will favor windward and mountain locations, especially through the overnight and early morning periods.

Discussion

No overnight surprises, so the forecast remains pretty much the same. High pressure to the northeast will be replaced by a high to our north this weekend. This new high will move to the northeast early next week, maintaining moderate to locally breezy trade winds. This trade wind flow will focus clouds and showers over the windward and mountain areas, although the moderate to breezy trades will carry some of the showers to central and leeward areas from time to time.
An upper level low is expect to linger northeast of the islands today before starting to slowly move to the east over the weekend. An associated shortwave trough is expected to swing through the islands Sunday/Sunday night from the north, however precipitable water looks to be below normal during this time. While the shortwave could help to enhance showers, the lack of moisture will likely limit rainfall amounts.

Aviation

Today through the weekend, breezy northeast trade winds will continue across the island chain. This will allow showers and cloud cover to favor north through east sections of the islands, particularly during the overnight and early morning hours each day. In general, VFR conditions are expected to prevail, but periods of MVFR will be possible within any heavier showers or bands of lower clouds.
AIRMET Sierra remains in effect for mountain obscuration for windward sections of the islands early this morning. Latest satellite and radar imagery show continued bands of clouds and showers approaching the islands from the east, so this AIRMET will likely be needed through at least mid-morning. Models indicate that some improvement can be expected later today, however.
Additionally, as the trade winds increase a bit today, AIRMET Tango may eventually be needed for low-level mechanical turbulence downstream of mountainous terrain.

Marine

High pressure north of the area will maintain locally windy trade winds through the coming week. A Small Craft Advisory remains in effect for the windy waters around Maui county and the Big Island through tomorrow afternoon. This will likely be extended.
The current south swell will linger through the weekend. Surf along south facing shores will subside Monday and Tuesday with only small surf through the rest of the coming week.
Surf will remain quite small along north facing shores through the weekend. A low over the Aleutians will send a small northwest swell into Hawaii waters starting Sunday night. As that swell fades, a west northwest swell from a low off Japan will likely produce small surf along north and west facing shores through mid-week.
The trade winds will produce choppy surf along east facing shores through the coming week. Wave heights will build a bit as the trade-wind fetch lengthens.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov