Hilo

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 78 to 84 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Showers likely in the evening, then frequent showers after midnight. Lows 63 to 70 near the shore to 52 to 57 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 80 percent.

Thursday: Cloudy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to 67 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 80 percent.

Kona

Today: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 83 to 88 near the shore to around 69 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 70 near the shore to around 53 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 81 to 86 near the shore to around 67 near 5000 feet. Southwest winds up to 10 mph. Chance of rain 40 percent.

Waimea

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 66 to 85. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 67 near the shore to 54 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Thursday: Breezy. Mostly cloudy with scattered showers. Highs around 81 near the shore to 72 to 79 near 3000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

Kohala

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 66 to 85. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 67 near the shore to 54 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Thursday: Breezy. Mostly cloudy with scattered showers. Highs around 81 near the shore to 72 to 79 near 3000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

South Big Island

Today: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 84 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 69 near the shore to around 51 near 5000 feet. Northeast winds up to 15 mph.

Thursday: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 84 near the shore to around 73 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Puna

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 78 to 84 near the shore to 65 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Showers likely in the evening, then frequent showers after midnight. Lows 63 to 70 near the shore to 52 to 57 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 80 percent.

Thursday: Cloudy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to 67 to 72 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 80 percent.

Waikoloa

Today: Mostly sunny. Isolated showers in the afternoon. Highs 82 to 88 near the shore to 68 to 73 above 4000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 72 near the shore to 49 to 57 above 4000 feet. Southeast winds up to 15 mph.

Thursday: Sunny in the morning then becoming partly sunny. Breezy. Highs around 84 near the shore to 68 to 74 above 4000 feet. Northeast winds up to 20 mph.

Detailed Forecast

Synopsis

After several days with light and variable winds, our more typical easterly trade wind regime has returned this morning and will continue through the upcoming weekend. Clouds and showers will favor windward and mauka locations, especially over the western end of the state where a band of moisture associated with an old front will linger through Thursday. Thereafter, a drier trade wind pattern is expected Friday through early next week.

Discussion

A transition period is anticipated today as a ridge noses eastward trailing a front that passed to the north. The light northeast flow will shift out of the east and increase into the moderate to breezy category later today through the second half of the week. Clouds and showers will shift back over windward and mauka locations, with the best chances being overnight through the early morning hours.
A residual band of moisture associated with the tail-end of the aforementioned front will linger over the western end of the state through Thursday, which will support better windward shower coverage. Although the windward showers will remain on the light/moderate side due to rising upper heights and stable conditions in place, rising streams can’t be ruled out if the showers remain focused over any location for long periods of time. The best chance of this scenario unfolding will be over the northern and windward slopes of Kauai where the moisture axis stalls.
Friday through the upcoming weekend, guidance depicts the previously discussed moisture axis diminishing with drier trade wind conditions filling in across the state.

Aviation

Remnants from the tail end of dying front will bring enhanced low level moisture to windward sides of Kauai and Oahu this morning. Expect scattered to numerous showers in this aforementioned area with periods of MVFR ceilings and visibility. Isolated showers are expected elsewhere. Trade winds will become slightly more established throughout the forecast period.
AIRMET Sierra remains in effect above 2000 feet for north thru east sides of Kauai due to tempo mountain obscuration from clouds and showers.

Marine

A large long period northwest to north swell will slowly subside through today. Latest swell data from the nearshore buoys suggest the surf has lowered to just below High Surf Warning criteria of 25 feet. Therefore, the Warning is now replaced with an Advisory. This advisory is good through late tonight. For the rest of the week and through early next week, expect a series of small to moderate northwest pulses reaching the islands’ north and west shores. This declining northwest to north swell will be shifting to the northeast today through Thursday, bringing a boost in the surf into the moderate range along the east facing shores on Thursday. The strengthening trades thereafter will hold the surf heights in the small to moderate range along east facing shores after Thursday.
A Small Craft Advisory (SCA) for elevated seas of 10 ft or higher remains in effect for the windward waters through late tonight. A new surface high is setting up shop northwest and north of the islands through Thursday. The building high will strengthen the trade winds to locally strong of 23 kt or higher by Thursday, and hold through the weekend. This increase will warrant an SCA that will be issued later today or tonight, for selected waters around Maui County and waters south of the Big Island. This SCA will continue into the weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Thursday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Small Craft Advisory until 6 AM HST Thursday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters, Big Island Windward Waters.

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Data Courtesy of NOAA.gov