Hilo

Tonight: Mostly cloudy with scattered showers. Lows 62 to 69 near the shore to 48 to 55 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers. Haze in the afternoon. Highs 78 to 83 near the shore to 65 to 70 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Saturday Night: Mostly cloudy with scattered showers. Haze. Lows 62 to 69 near the shore to 48 to 55 at 4000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Kona

Tonight: Partly cloudy. Haze. Lows around 71 near the shore to 44 to 51 near 5000 feet. Light winds.

Saturday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Haze through the day. Highs 84 to 89 near the shore to around 67 near 5000 feet. Light winds. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Haze. Lows 69 to 74 near the shore to 45 to 51 near 5000 feet. Light winds.

Waimea

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows 61 to 69 near the shore to 51 to 59 near 3000 feet. East winds up to 25 mph with gusts to 45 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Breezy. Haze in the afternoon. Highs around 80 near the shore to 71 to 78 near 3000 feet. East winds up to 20 mph.

Saturday Night: Partly cloudy. Breezy. Isolated showers in the evening. Haze through the night. Lows 61 to 70 near the shore to 52 to 60 near 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Kohala

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows 61 to 69 near the shore to 51 to 59 near 3000 feet. East winds up to 25 mph with gusts to 45 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Breezy. Haze in the afternoon. Highs around 80 near the shore to 71 to 78 near 3000 feet. East winds up to 20 mph.

Saturday Night: Partly cloudy. Breezy. Isolated showers in the evening. Haze through the night. Lows 61 to 70 near the shore to 52 to 60 near 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

South Big Island

Tonight: Mostly clear. Breezy and haze. Lows around 72 near the shore to around 49 near 5000 feet. Northeast winds 10 to 20 mph.

Saturday: Mostly sunny. Breezy. Haze through the day. Isolated showers in the afternoon. Highs around 86 near the shore to around 67 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Breezy and haze. Lows around 72 near the shore to around 50 near 5000 feet. Northeast winds 10 to 20 mph.

Puna

Tonight: Mostly cloudy with scattered showers. Lows 62 to 69 near the shore to 48 to 55 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers. Haze in the afternoon. Highs 78 to 83 near the shore to 65 to 70 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Saturday Night: Mostly cloudy with scattered showers. Haze. Lows 62 to 69 near the shore to 48 to 55 at 4000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Partly cloudy. Breezy and haze. Lows 68 to 74 near the shore to 47 to 53 above 4000 feet. Southeast winds up to 25 mph.

Saturday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Haze through the day. Highs 82 to 88 near the shore to 63 to 72 above 4000 feet. Southwest winds up to 10 mph shifting to the northwest in the afternoon. Gusts up to 30 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Haze. Lows 69 to 74 near the shore to 47 to 53 above 4000 feet. Southeast winds up to 15 mph.

Detailed Forecast

Synopsis

An area of high pressure well north of the islands will aid in maintaining breezy trade winds through the remainder of this week into next week, gradually increasing in strength toward the latter half of next week. Periods of showers will favor windward and mountain areas, with leeward areas remaining mostly dry.

Discussion

The latest observations show isolated shower activity the vicinity of the islands under a typical trade wind pattern, expected to increase in strength over the upcoming weekend and into next week. Latest model guidance is in good agreement showcasing a broad, 1029 mb area of high pressure will persist north of the islands, expecting to move eastward over the next couple days, with an elongated frontal passage in its immediate wake. The area of high pressure will aid in maintaining a relatively stable environment, with only subtle changes in the wind direction through late Monday of next week.
By next week, a new, stronger area of high pressure will propagate eastward while remaining well north of the islands. The aforementioned frontal passage is expected to weaken as it gets overrun by the established trades, implying trades will remain moderate to breezy through much of next week. Expect periods of showers to favor primarily windward and mountain areas, while limited rainfall will be expected on leeward areas with exception to occasional isolated showers during the overnight hours.

Aviation

VFR conditions are expected to prevail across most of the state tonight with brief MVFR ceilings in showers across windward Big Island and Maui overnight. Breezy trade winds and stable conditions will bring tempo moderate turbulence below 7000 feet (all islands) where AIRMET Tango is posted, and will likely continue in the coming days. No other AIRMETs are in effect or expected tonight.

Marine

Surface high pressure north northwest of the state will strengthen and move east over the weekend. This will result in continuing moderate/fresh to locally strong trade winds. A Small Craft Advisory (SCA) remains in effect through Sunday morning for the typical windier channels and bays surrounding Maui County and south of Big Island. This could be extended further into the beginning of next week if trade wind speeds hold. Trade winds could then further strengthen around the middle of next week as a new stronger high is forecast to build north of the islands.
The current small, medium period north northwest swell (4 feet 13 seconds) is producing head to slightly over head high surf along north facing shores and will hold today before gradually declining this weekend. A series of smaller northwest to north swells are expected next week that should produce near head high surf.
A near 3 foot, medium to long period south southwest swell that peaked late last night will linger through Saturday. This swell has resulted in fun above summer average surf heights (5 to 6 foot on face) across many south-facing surf zones. This surf will hold today and Saturday before slowly subsiding early next week. A mix of both a reinforcing long period south southwest swell and new short period south southeast swell energy should maintain near to above seasonal average surf this weekend. South-facing shore surf will generally decline next week, but small south southwest swells will hold surf at near summertime averages through the middle of next week. East facing shores will remain rough and choppy from the trade winds.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov