Hilo

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 83 near the shore to 66 to 73 at 4000 feet. Northeast winds around 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 72 near the shore to 55 to 60 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

Friday: Partly sunny. Scattered showers in the morning, then showers likely in the afternoon. Highs around 83 near the shore to 65 to 73 at 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Sunny in the morning, then cloudy with scattered showers in the afternoon. Highs 82 to 88 near the shore to around 70 near 5000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows around 73 near the shore to 51 to 57 near 5000 feet. Light winds. Chance of rain 30 percent.

Friday: Sunny in the morning, then cloudy with scattered showers in the afternoon. Highs 82 to 88 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 50 percent.

Waimea

Today: Sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 69 to 88. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows 64 to 69 near the shore to 55 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny with scattered showers in the morning, then mostly cloudy with showers likely in the afternoon. Highs 68 to 88. East winds 10 to 15 mph. Chance of rain 70 percent.

Kohala

Today: Sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 69 to 88. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows 64 to 69 near the shore to 55 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny with scattered showers in the morning, then mostly cloudy with showers likely in the afternoon. Highs 68 to 88. East winds 10 to 15 mph. Chance of rain 70 percent.

South Big Island

Today: Breezy. Sunny in the morning, then cloudy with scattered showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows around 73 near the shore to around 53 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Sunny in the morning, then cloudy with scattered showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Puna

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 83 near the shore to 66 to 73 at 4000 feet. Northeast winds around 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 72 near the shore to 55 to 60 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

Friday: Partly sunny. Scattered showers in the morning, then showers likely in the afternoon. Highs around 83 near the shore to 65 to 73 at 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 81 to 89 near the shore to 67 to 75 above 4000 feet. North winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to 50 to 58 above 4000 feet. Light winds. Chance of rain 20 percent.

Friday: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 80 to 89 near the shore to 67 to 74 above 4000 feet. Light winds. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Light winds will continue today, with mostly sunny skies this morning giving way to some afternoon clouds and a few interior and leeward showers as sea breezes develop. Trade winds will gradually increase tonight through Friday, becoming locally breezy by Saturday. A trend toward lighter trade winds is expected late Sunday into next week. An area of increased moisture arriving tomorrow will fuel an increase in windward showers, but should clear the islands in time for the weekend, which should feature limited windward showers.

Discussion

A surface ridge several hundred miles N of the islands is resulting in light E to SE winds over the area, now that a low-level trough W of Kauai has dissipated. With the ridge in this position, E winds are a little stronger near Maui and the Big Island as compared to the lighter SE winds near Kauai, but offshore-flowing drainage winds prevail in many areas this morning. Overnight soundings indicate that the atmosphere is a little more moist and unstable near Kauai versus the Big Island, likely due to the moisture left behind by the surface trough, with radar detecting a few small heavy showers over Kauai waters. Satellite shows few low clouds near and over Oahu and Maui County, with scattered to broken low clouds moving toward windward Big Island, and over Kauai waters.
Winds will remain on the lighter side today as the surface ridge remains just N of Kauai. Morning land breezes and mostly sunny skies will give way to sea breezes that will likely support interior and leeward clouds and a few showers, but limited moisture supply is expected in most areas, except near Kauai, where showers may be a little more widespread. The ridge will remain close to Kauai through tonight, but will be gradually strengthening thereafter as it moves N, allowing trade winds to build from E to W across the island chain. Trade winds are expected to be locally breezy by Saturday.
Increased moisture currently seen near 150W is expected to move in from the E tomorrow and tomorrow night at the same time a weak low aloft arrives from the E. This will very likely lead to an increase in trade wind showers, which will focus primarily over windward coasts and slopes. Fairly typical and locally breezy trade wind weather is expected over the weekend as this moisture moves W of the area, with a just a few brief windward showers expected. Latest guidance indicates that winds will begin to gradually diminish as early as Sunday as the high to the NNE is replaced by a low and front, with lighter trade winds and stable weather anticipated during the first half of next week. Stronger trades and continued stable weather is the most likely outcome for the second half of next week.

Aviation

Light to moderate easterly trades will hold in place today and tonight, with sea breezes developing in many areas today, and land breezes developing tonight in the more sheltered locales. Low clouds and a few showers will be possible mainly along windward slopes and coasts early this morning, with cloud build ups and scattered showers then expected over the island interiors this afternoon into this evening. The showers should diminish quickly with loss of daytime heating this evening, with perhaps an increase in trade showers over the eastern islands toward daybreak Friday.
No AIRMETs are currently in effect.

Marine

As the influence of a dissipated surface trough wanes, trades will be on the increase into the weekend. Expect winds to reach Small Craft Advisory strength across the typically breezy waters around Maui County and the Big Island by Friday night or Saturday.
A new, small south swell is expected to roll through local waters today through Sunday. Also, the current small mid-period northwest swell will lower gradually through Friday. Short-period choppy surf along east facing shores will remain rather small through Friday, with a gradual uptick expected over the weekend as trade winds gradually strengthen. Overall, no significant swells are anticipated through the middle of next week.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov