Hilo

Today: Occasional showers, mainly before 1pm. High near 80. East northeast wind 11 to 13 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Occasional showers, mainly after 7pm. Low around 66. Northeast wind 6 to 11 mph becoming light and variable in the evening. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Occasional showers, mainly before 1pm. High near 81. Light and variable wind becoming northeast 5 to 8 mph in the morning. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Isolated showers. Partly sunny, with a high near 80. West southwest wind 10 to 13 mph becoming northwest in the afternoon. Chance of precipitation is 20%.

Tonight: Scattered showers, mainly before midnight. Mostly cloudy, with a low around 67. West southwest wind 3 to 6 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Isolated showers after noon. Increasing clouds, with a high near 79. Southwest wind around 6 mph. Chance of precipitation is 20%.

Waimea

Today: Occasional showers, mainly before 1pm. High near 75. Breezy, with an east northeast wind 11 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 56. Breezy, with a northeast wind 11 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Sunday: Scattered showers. Partly sunny, with a high near 75. East northeast wind 9 to 13 mph. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Occasional showers. High near 70. East northeast wind around 14 mph, with gusts as high as 20 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Occasional showers. Low around 54. East wind 3 to 6 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

Sunday: Showers likely. Mostly cloudy, with a high near 68. East wind around 11 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 83. Windy, with an east wind around 26 mph, with gusts as high as 34 mph.

Tonight: Isolated showers. Partly cloudy, with a low around 72. Windy, with an east northeast wind around 26 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Sunday: Isolated showers before noon. Mostly sunny, with a high near 83. Breezy, with an east wind 17 to 20 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.

Puna

Today: Occasional showers, mainly before noon. High near 76. Breezy, with a northeast wind around 17 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

Tonight: Occasional showers. Low around 63. North wind 8 to 10 mph becoming west northwest after midnight. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

Sunday: Showers likely, mainly before noon. Mostly cloudy, with a high near 76. North wind around 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.

Waikoloa

Today: Sunny, with a high near 83. North wind 10 to 13 mph.

Tonight: Mostly clear, with a low around 66. Windy, with an east northeast wind 15 to 23 mph, with gusts as high as 32 mph.

Sunday: Sunny, with a high near 83. North northeast wind around 6 mph.

Detailed Forecast

Synopsis

High pressure north of the islands will keep moderate to occasionally breezy trade winds blowing into next week. Low clouds and showers will focus over windward areas, with showers most active during nights and mornings, when they will be more likely to spread leeward on the smaller islands. Daytime heating will produce clouds and a few showers over the leeward slopes of the Big Island during the afternoons and evenings.

Discussion

Moderate to locally breezy trade winds are likely to persist through the weekend and into next week, initially supported by a high pressure cell centered far NNW of the islands. Although the E flank of the high will be impacted by a front and complex low in the NE Pacific this weekend, the associated low-level pressure gradient over the islands looks to remain tight enough to keep moderate trade winds in place. With daytime heating abetting vertical mixing, afternoons will still feature some locally breezy conditions. On the flip side, sheltered leeward areas will likely see fairly light overnight winds. As the NE Pacific low dissipates late this weekend, the high will move E and settle into a more typical position far NE of the islands during the early to middle part of next week, maintaining moderate trade winds.
With trade winds blowing, showery low cloud clusters will focus over windward portions of the islands, occasionally spreading into communities immediately leeward of the mountains. Showers will be most active during the nights and mornings, but a mid-level ridge over the area will preclude heavy showers through early next week. Guidance depicts a slow-moving destabilizing mid-level low developing near the islands by Tuesday, which could lead to an increase in shower coverage and intensity, especially as moisture associated with the aforementioned front nears Kauai and Oahu.
In the meantime, latest satellite images show a loosely organized NW-SE oriented band of showery and stable low clouds over and just upstream of the islands. This will likely clear most islands by mid-morning, with shower coverage diminishing in the afternoon. Model guidance indicates little in the way of organized moisture sources until the front arrives from the N early next week, and subsidence ahead of this feature may lead to reduced shower coverage on Monday before arriving on Kauai, and potentially Oahu, on Tuesday.

Aviation

Breezy trades will continue to focus clouds, showers, and occasional MVFR conditions over the windward coasts and slopes of all the islands for the next several hours. Aviation conditions will improve during mid to late morning as the resident band of moisture shifts west of the area. Prevailing VFR can then be expected at all locations for the remainder of the day.
AIRMET Sierra for mountain obscuration remains in effect for all windward sections.
AIRMET Tango for lee turbulence remains in effect.

Marine

A surface high is forecast to stay far north and northeast of the islands into the first half of next week, resulting in continuing trade winds through this stretch. The high is in the process of weakening that will cause a slight drop in the strength of the trades from locally strong to moderate by tonight. It will hold at moderate strength to about Monday night before bumping up a notch Tuesday into Wednesday. A Small Craft Advisory is in effect today for the selected waters of Maui County and waters south of the Big Island. Small Craft Advisory level winds will return by Tuesday.
A north to northeast pulse is slated to arrive Monday, bumping the surf along north facing shores and some east facing shores with a northern exposure into the small to moderate range. The weaker trade winds slightly lower surf in the small range for the east facing shores over the weekend and into early next week. Surf may increase a foot or so around the middle of next week when the trade winds are expected to return to locally strong. A series of small but long period south and southwest swells will maintain small surf along the south facing shores into next week.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov