Hilo

Today: Cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 84 near the shore to around 65 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Showers likely in the evening, then occasional showers after midnight. Lows 62 to 71 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain near 100 percent.

Saturday: Occasional showers in the morning, then occasional showers and slight chance of thunderstorms in the afternoon. Highs 74 to 80 near the shore to around 61 at 4000 feet. Northeast winds up to 15 mph. Chance of rain near 100 percent.

Kona

Today: Mostly sunny in the morning then becoming mostly cloudy. Isolated showers. Highs around 81 near the shore to around 68 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Isolated showers in the evening. Lows 65 to 70 near the shore to 48 to 55 near 5000 feet. Light winds. Chance of rain 20 percent.

Saturday: Mostly cloudy. Scattered showers and slight chance of thunderstorms in the afternoon. Highs around 77 near the shore to around 64 near 5000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Waimea

Today: Breezy. Mostly cloudy with isolated showers. Highs around 80 near the shore to 70 to 75 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Scattered showers in the evening, then occasional showers after midnight. Lows around 64 near the shore to 55 to 62 near 3000 feet. East winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain near 100 percent.

Saturday: Breezy. Occasional showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 76 near the shore to 66 to 71 near 3000 feet. East winds up to 25 mph. Chance of rain near 100 percent.

Kohala

Today: Breezy. Mostly cloudy with isolated showers. Highs around 80 near the shore to 70 to 75 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Scattered showers in the evening, then occasional showers after midnight. Lows around 64 near the shore to 55 to 62 near 3000 feet. East winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain near 100 percent.

Saturday: Breezy. Occasional showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 76 near the shore to 66 to 71 near 3000 feet. East winds up to 25 mph. Chance of rain near 100 percent.

South Big Island

Today: Mostly sunny in the morning then becoming partly sunny. Breezy. Highs around 81 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Tonight: Mostly cloudy. Isolated showers in the evening. Lows 66 to 72 near the shore to around 51 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the afternoon. Highs around 77 near the shore to around 65 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Puna

Today: Cloudy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 84 near the shore to around 65 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Showers likely in the evening, then occasional showers after midnight. Lows 62 to 71 near the shore to 53 to 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain near 100 percent.

Saturday: Occasional showers in the morning, then occasional showers and slight chance of thunderstorms in the afternoon. Highs 74 to 80 near the shore to around 61 at 4000 feet. Northeast winds up to 15 mph. Chance of rain near 100 percent.

Waikoloa

Today: Sunny in the morning then becoming partly sunny. Breezy. Highs around 81 near the shore to 64 to 71 above 4000 feet. Northeast winds up to 25 mph.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows 66 to 71 near the shore to 50 to 55 above 4000 feet. East winds up to 25 mph shifting to the southeast up to 10 mph after midnight. Chance of rain 20 percent.

Saturday: Mostly cloudy. Breezy. Isolated showers in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs around 77 near the shore to 60 to 67 above 4000 feet. Northeast winds up to 15 mph increasing to up to 25 mph in the afternoon. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Breezy easterly trade winds will continue through next week, with clouds and showers favoring windward and mauka locations. Increasing moisture combined with an upper disturbance settling southward into the area will result in better windward shower coverage tonight through the weekend, with some occasionally reaching our dry leeward areas. A return of drier trade wind conditions is expected early next week.

Discussion

Guidance remains in good agreement and depicts the dry and breezy trade wind conditions holding today, with the best rainfall chances remaining over windward and mountain locations through the morning hours. A transition period is anticipated late tonight through the weekend as upper heights lower ahead of an approaching short wave trough. Added instability associated with this upper feature combined with increasing deep layer moisture (PWs climbing into the 1.4 to 1.8 inch range by Saturday – highest eastern end of the state) will translate to better rainfall chances. Showers may become heavy at times, with some making into our dry leeward areas where drought conditions persist. Although confidence is low given the expected shield of high clouds, a few afternoon thunderstorms can't be ruled out over Big Island slopes Saturday and Sunday.
A return of a more typical trade wind pattern is expected through the first half of the upcoming week as upper heights rise and some drier air moves in.

Aviation

With high pressure centered far northeast of the state, trade winds will remain in the moderate to breezy range today. Showers, with any accompanying MVFR conditions, will mainly affect windward and mauka areas. However, VFR will prevail over most sections most of the time.
An AIRMET continues in effect for low level turbulence to the lee of the mountains across the state.

Marine

High pressure northwest of the islands will keep moderate to strong trades in place through the forecast period, with only minor variations in strength. A Small Craft Advisory (SCA) is now in effect through 6 PM Sunday for the typically windy waters around Maui and the Big Island.
Moderate to locally strong trade winds will keep east shore surf close to seasonal levels through Saturday. Surf will then lower below normal Sunday through the middle of next week as the trade winds diminish upstream of the island chain.
South shore surf will remain small through Friday, then trend up to slightly above normal levels Saturday through Monday as a new moderate size south swell moves through. Surf will then lower back to small levels Tuesday through Thursday.
A series of small northwest swells will move through the area today through the weekend, maintaining small surf along north facing shores. A larger, long period northwest swell associated with Typhoon Malakas, will arrive Monday night, giving a noticeable boost to surf along north and west facing shores Tuesday through late next week.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov