Hilo

Rest Of Today: Breezy. Scattered showers in the morning, then showers in the afternoon. Highs 75 to 82 near the shore to 61 to 67 at 4000 feet. North winds up to 10 mph shifting to the northeast up to 20 mph in the afternoon. Chance of rain near 100 percent.

Tonight: Cloudy and windy. Showers in the evening, then numerous showers after midnight. Lows 57 to 65 near the shore to around 51 at 4000 feet. North winds up to 25 mph increasing to 10 to 30 mph after midnight. Chance of rain 90 percent.

Saturday: Windy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 71 to 78 near the shore to 56 to 63 at 4000 feet. North winds 10 to 30 mph. Chance of rain 50 percent.

Kona

Rest Of Today: Partly sunny with scattered showers. Highs 79 to 84 near the shore to around 65 near 5000 feet. West winds up to 10 mph. Gusts up to 30 mph in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows around 68 near the shore to 41 to 49 near 5000 feet. Light winds. Chance of rain 40 percent.

Saturday: Mostly sunny. Isolated showers in the morning. Highs 79 to 84 near the shore to around 64 near 5000 feet. Northeast winds up to 10 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Waimea

Rest Of Today: Cloudy and breezy. Numerous showers in the morning, then showers in the afternoon. Highs around 75 near the shore to 64 to 70 near 3000 feet. Northwest winds up to 10 mph shifting to the north up to 25 mph in the afternoon. Chance of rain 90 percent.

Tonight: Breezy. Cloudy with showers. Lows 57 to 64 near the shore to 49 to 56 near 3000 feet. Northeast winds up to 25 mph increasing to 10 to 25 mph after midnight. Gusts up to 45 mph. Chance of rain 90 percent.

Saturday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 69 to 74 near the shore to 59 to 67 near 3000 feet. Northeast winds 10 to 25 mph with gusts to 45 mph. Chance of rain 50 percent.

Kohala

Rest Of Today: Cloudy and breezy. Numerous showers in the morning, then showers in the afternoon. Highs around 75 near the shore to 64 to 70 near 3000 feet. Northwest winds up to 10 mph shifting to the north up to 25 mph in the afternoon. Chance of rain 90 percent.

Tonight: Breezy. Cloudy with showers. Lows 57 to 64 near the shore to 49 to 56 near 3000 feet. Northeast winds up to 25 mph increasing to 10 to 25 mph after midnight. Gusts up to 45 mph. Chance of rain 90 percent.

Saturday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 69 to 74 near the shore to 59 to 67 near 3000 feet. Northeast winds 10 to 25 mph with gusts to 45 mph. Chance of rain 50 percent.

South Big Island

Rest Of Today: Partly sunny with scattered showers. Highs around 80 near the shore to around 65 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Scattered showers in the evening. Lows around 69 near the shore to around 48 near 5000 feet. East winds up to 10 mph in the evening becoming light. Chance of rain 30 percent.

Saturday: Mostly sunny. Highs around 80 near the shore to around 65 near 5000 feet. Northeast winds up to 10 mph shifting to the southeast in the afternoon.

Puna

Rest Of Today: Breezy. Scattered showers in the morning, then showers in the afternoon. Highs 75 to 82 near the shore to 61 to 67 at 4000 feet. North winds up to 10 mph shifting to the northeast up to 20 mph in the afternoon. Chance of rain near 100 percent.

Tonight: Cloudy and windy. Showers in the evening, then numerous showers after midnight. Lows 57 to 65 near the shore to around 51 at 4000 feet. North winds up to 25 mph increasing to 10 to 30 mph after midnight. Chance of rain 90 percent.

Saturday: Windy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 71 to 78 near the shore to 56 to 63 at 4000 feet. North winds 10 to 30 mph. Chance of rain 50 percent.

Waikoloa

Rest Of Today: Breezy. Partly sunny with scattered showers. Highs 77 to 83 near the shore to 62 to 67 above 4000 feet. Northwest winds up to 15 mph shifting to the north up to 25 mph in the afternoon. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows around 67 near the shore to 43 to 50 above 4000 feet. Northeast winds up to 30 mph. Chance of rain 50 percent.

Saturday: Mostly sunny. Windy. Isolated showers in the morning. Highs 75 to 83 near the shore to 61 to 66 above 4000 feet. Northeast winds up to 30 mph with gusts to 50 mph. Chance of rain 20 percent.

Detailed Forecast

Update

Central valley and windward Maui added to the wind advisory.

Synopsis

The weather impacts through this weekend and into early next week are wind driven. Expect strengthening northerly winds starting today behind a rapidly moving cold front. These strong northerly winds turn into windy northeast to east trade winds from early Saturday morning into the first half of next week affecting all Hawaiian Islands. Strong trades gradually drop down to moderate to locally breezy levels by next week Thursday. Wet weather will continue today statewide with decreasing rainfall trends developing after the cold front passes through each island. Trade wind showers return starting late Saturday to Sunday mainly over windward and mountain areas with drier conditions forecast over leeward areas.

Discussion

The morning big picture satellite imagery shows the cold front is moving into Kauai with cloud and showers from the front merging with the nearly stationary surface trough near Maui. Local radar imagery continues to show light to moderate showers developing statewide. Wet weather will continue today statewide today with decreasing rainfall trends developing after the cold front passes through each island. Trade wind showers return starting late Saturday to Sunday mainly over windward and mountain areas with drier conditions forecast over leeward areas.
This cold front will sweep across the state today with strong northerly winds filling in behind the front as it passes through each island. Wind speeds will accelerate to advisory levels over all islands through the day with the strongest wind speeds and highest wind gusts forecast over and down wind of mountains, and along west and east slopes of island terrain. A Wind Advisory was issued for all islands to cover these stronger wind impacts lasting through Sunday. Even stronger wind speeds are forecast over the highest elevation summits of Mauna Kea and Mauna Loa on the Big Island, where a High Wind Warning was issued this morning.
An extended period of strong trade winds will continue into the first half of next week. A strong high pressure system will build into the region through early next week producing strong to windy trade winds. Wind directions will veer from northerly windy today and tonight, to a more northeasterly direction on Saturday, to a more easterly direction from Sunday through Monday.
Strong winds will gradually decrease each day from Tuesday onward, where the easterly trade winds will blow at more moderate to locally breezy levels by Thursday. Another low pressure system will move into the Central Pacific basin by the end of next week, with decreasing southeasterly winds in the forecast as the trailing cold front breaks down the high pressure ridge north of the islands.

Aviation

Bands of clouds and showers ahead of an approaching cold front continue to stream out of the west-northwest. As of 2 AM HST this morning, late night radar imagery indicated most of the shower activity to be focused over Maui County and spreading quickly eastward. Occasional MVFR ceilings and visibilities are associated with this shower activity. AIRMET Sierra for mountain obscuration now includes Oahu, Molokai, Lanai, and Maui, and will likely be further expanded to include northwest exposures of the Big Island later this morning.
Winds will shift from west to north today as the front passes over the western islands. Drier conditions and gusty winds are expected behind the front. AIRMET Tango for low level turbulence to the south and west of island terrain will likely be needed for Kauai and Oahu later this morning and the rest of the state by late evening.

Marine

High pressure to the distant northwest will build eastward in the vicinity of 30N, pushing a cold front southeastward through the island chain today and tonight. North winds gradually increase today, with SCA level winds expected across all waters by late this afternoon. The high will strengthen and shift northeastward Saturday and Saturday night, before settling southward and closer to the islands Sunday through the middle of next week. Strong to near Gale force winds are expected during this time, with the strongest winds in the windier waters around Maui and the Big Island, where Gale force winds are possible. A Gale Watch remains in effect for these areas Saturday through Sunday. A Small Craft Advisory is now in effect for all marine zones today and tonight, and for areas outside of the Gale Watch through Tuesday.
A pair of overlapping north to north-northeast swells continue to run higher than predicted at nearshore buoys early this morning. As a result, a High Surf Advisory is in effect for north and east facing shores of most islands through Sunday as well as west facing shores of Maui. Given the strong north to northeast winds along with the north-northeast swell direction, impacts are also likely from harbor surges at exposed northern harbors, including Hilo and Kahului harbors. See the Marine Weather Statement for additional details.
Advisory level surf may linger through Monday along north and east facing shores, as a new large northwest swell builds and easterly trade wind swell trends higher, even as the north-northeast swell declines. North shore surf should lower below advisory thresholds by Tuesday, with east shore surf likely holding at advisory levels through Wednesday. Surf should lower below advisory levels along east facing shores by Thursday as the trades begin to ease.
South shore surf will remain small through late next week.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Sunday for north and east facing shores of Niihau, Kauai, Oahu, Molokai, Maui and Big Island.
Wind Advisory until 6 PM HST Sunday for all low elevation areas.
High Wind Warning until 6 AM HST Saturday for Big Island Summits.
Gale Watch from Saturday morning through Sunday afternoon for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Southeast Waters.
Small Craft Advisory until 6 AM HST Saturday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Southeast Waters.
Small Craft Advisory until 6 PM HST Tuesday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Big Island Windward Waters, Big Island Leeward Waters.

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Data Courtesy of NOAA.gov