Hilo

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 57 to 65 near the shore to 47 to 53 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Thanksgiving Day: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 81 near the shore to 61 to 68 at 4000 feet. North winds up to 15 mph. Chance of rain 40 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 57 to 64 near the shore to 46 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Kona

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 67 near the shore to 42 to 49 near 5000 feet. Light winds. Chance of rain 20 percent.

Thanksgiving Day: Mostly sunny. Isolated showers in the afternoon. Highs 80 to 85 near the shore to around 67 near 5000 feet. Southwest winds up to 10 mph. Chance of rain 20 percent.

Thursday Night: Partly cloudy with isolated showers. Lows around 67 near the shore to 41 to 47 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 57 to 66 near the shore to 50 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Thanksgiving Day: Breezy. Mostly sunny with isolated showers. Highs 61 to 80. East winds up to 20 mph. Chance of rain 20 percent.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Kohala

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 57 to 66 near the shore to 50 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Thanksgiving Day: Breezy. Mostly sunny with isolated showers. Highs 61 to 80. East winds up to 20 mph. Chance of rain 20 percent.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

South Big Island

Tonight: Mostly clear. Isolated showers in the evening. Lows around 68 near the shore to around 48 near 5000 feet. Light winds. Chance of rain 20 percent.

Thanksgiving Day: Sunny. Highs around 83 near the shore to around 65 near 5000 feet. East winds up to 15 mph.

Thursday Night: Mostly clear. Lows around 68 near the shore to around 47 near 5000 feet. Northeast winds up to 15 mph.

Puna

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 57 to 65 near the shore to 47 to 53 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Thanksgiving Day: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 81 near the shore to 61 to 68 at 4000 feet. North winds up to 15 mph. Chance of rain 40 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 57 to 64 near the shore to 46 to 52 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Mostly clear. Breezy. Lows 65 to 70 near the shore to around 48 above 4000 feet. East winds up to 20 mph.

Thanksgiving Day: Sunny and breezy. Highs 80 to 86 near the shore to 63 to 70 above 4000 feet. Northeast winds up to 20 mph.

Thursday Night: Mostly clear. Lows 64 to 69 near the shore to around 47 above 4000 feet. Southeast winds up to 15 mph.

Detailed Forecast

Synopsis

Trade winds then strengthen and shift from a more easterly Thursday and Thursday night before weakening again Friday through the early next week. Conditions will remain fairly stable with a few clouds and light, mostly windward showers through the weekend.

Discussion

High pressure far to the north northeast is driving moderate trade winds this afternoon. Visible satellite and radar show a small band of low clouds and isolated showers tracking southward brushing against the Big Island. Windward slopes of the Big Island will see some cloud cover tonight, but elsewhere, mostly clear to partly cloudy skies are forecast to prevail.
Winds will veer more easterly and boost into the moderate to locally fresh range Thursday and Thursday night. Winds will gradually taper off Friday through Sunday as a front approaches and stalls then weakens about 350 miles northwest of Kauai. Winds will shift out of the south by Sunday into next week, but will be light enough for localized daytime sea breezes and nighttime land breezes. Conditions will remain fairly stable with a few clouds and light, mostly windward showers through the weekend.
Another stronger front moving in from the northwest will follow next week keeping the state in a light wind and stable weather pattern through midweek. Long range models show the front reaching Kauai around Thursday stalling out somewhere between Kauai and Oahu. Rainfall with this front will mainly fall along the frontal zone.

Aviation

Moderate northeast trades will continue for the next several days. Shower activity will be minimal through much of Thursday, with a focus on windward slopes. No AIRMETs are in effect, nor expected through tonight.

Marine

Weak high pressure will fill in north of the islands downstream of an approaching cold front from the northwest through Thanksgiving Day. This will maintain moderate to locally fresh trades from through Saturday. A Small Craft Advisory is in effect through early Friday morning for the Alenuihaha Channel to account for these enhanced channeling trades between Maui and Big Island. As the front weakens and hangs up north of the nearshore waters this weekend, high pressure settling in over the state will relax early week winds to just light and gentle breezes. Seas will reach and likely exceed the 10 foot Small Craft Advisory significant wave height threshold Friday through Saturday with the passage of a large northwest swell.
A combination of small, medium period north northwest swell and lingering shorter period north northeast swell will hold small surf along exposed north and west-facing shores through Thanksgiving. A hurricane force low approximately 1,600 nautical miles northwest of Kauai will send a large, long period northwest swell through the area Friday. The peak of this swell Friday will likely drive north-facing shore surf heights to warning levels late Friday into early Saturday. There may be just enough of a westerly component to this swell to allow west energy to creep into Kona Big Island's waters and push west-facing Big Island surf to 8 foot advisory levels. The northwest swell will trend downward from Saturday through Monday with surf heights falling below advisory heights on Sunday.
East-facing shore surf will remain elevated, but well below advisory levels, through the holiday weekend as a result of both a loitering small, short period northeast swell and a small northeast pulse arrival on Thanksgiving.
Surf along south-facing shores will remain seasonably small, driven by a mix of short period southeast and background long period south southwest swells. An upward trend is expected from this weekend through the first week of December. This as a result of more active weather east of New Zealand that will aim higher southerly swell toward the state.

Fire weather

We do not foresee any critical fire weather conditions developing through the first half of next week as wind speeds will remain below critical thresholds. Dry relative humidity levels may briefly touch fire weather criteria over drier leeward zones through the rest of the week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 8 AM HST Friday for Alenuihaha Channel.

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Data Courtesy of NOAA.gov