Hilo

Today: Sunny and breezy. Highs 82 to 88 near the shore to around 73 at 4000 feet. North winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Gusts up to 50 mph.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 67 to 72 near the shore to around 56 at 4000 feet. Northwest winds up to 20 mph with gusts to 45 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 82 to 88 near the shore to around 72 at 4000 feet. Northwest winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Kona

Today: Sunny. Highs around 87 near the shore to around 72 near 5000 feet. South winds up to 10 mph shifting to the west in the afternoon.

Tonight: Partly cloudy. Lows around 75 near the shore to around 55 near 5000 feet. Light winds.

Wednesday: Sunny in the morning, then partly sunny with isolated light showers in the afternoon. Highs 84 to 89 near the shore to around 72 near 5000 feet. Light winds becoming west up to 10 mph in the afternoon. Chance of rain 20 percent.

Waimea

Today: Sunny. Very windy. Highs 71 to 85. East winds 10 to 40 mph increasing to 20 to 40 mph in the afternoon. Gusts up to 65 mph.

Tonight: Partly cloudy. Very windy. Isolated showers after midnight. Lows around 69 near the shore to 57 to 63 near 3000 feet. East winds 10 to 40 mph. Gusts up to 65 mph in the evening. Chance of rain 20 percent.

Wednesday: Mostly sunny. Windy. Isolated light showers in the afternoon. Highs around 82 near the shore to 75 to 81 near 3000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Kohala

Today: Sunny. Very windy. Highs 71 to 85. East winds 10 to 40 mph increasing to 20 to 40 mph in the afternoon. Gusts up to 65 mph.

Tonight: Partly cloudy. Very windy. Isolated showers after midnight. Lows around 69 near the shore to 57 to 63 near 3000 feet. East winds 10 to 40 mph. Gusts up to 65 mph in the evening. Chance of rain 20 percent.

Wednesday: Mostly sunny. Windy. Isolated light showers in the afternoon. Highs around 82 near the shore to 75 to 81 near 3000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

South Big Island

Today: Sunny and windy. Highs around 87 near the shore to around 73 near 5000 feet. East winds 10 to 35 mph with gusts to 55 mph.

Tonight: Mostly clear. Windy. Lows 70 to 75 near the shore to around 54 near 5000 feet. East winds 10 to 35 mph.

Wednesday: Sunny and windy. Highs around 87 near the shore to around 71 near 5000 feet. East winds 10 to 30 mph decreasing to 10 to 20 mph in the afternoon.

Puna

Today: Sunny and breezy. Highs 82 to 88 near the shore to around 73 at 4000 feet. North winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Gusts up to 50 mph.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 67 to 72 near the shore to around 56 at 4000 feet. Northwest winds up to 20 mph with gusts to 45 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 82 to 88 near the shore to around 72 at 4000 feet. Northwest winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Waikoloa

Today: Sunny. Very windy. Highs 84 to 91 near the shore to 72 to 77 above 4000 feet. East winds up to 40 mph with gusts to 65 mph.

Tonight: Mostly clear. Windy. Lows around 75 near the shore to 53 to 58 above 4000 feet. Southeast winds up to 35 mph. Gusts up to 65 mph in the evening.

Wednesday: Sunny and windy. Highs 84 to 90 near the shore to 71 to 76 above 4000 feet. Southeast winds up to 25 mph shifting to the north in the afternoon.

Detailed Forecast

Synopsis

Strong and potentially damaging easterly winds along with very dry conditions will persist into Wednesday as Hurricane Dora passes far to the south. A return of a more typical trade wind pattern is anticipated later in the week through the weekend.

Discussion

Deep layer ridging combined with an anomalously strong pressure gradient over the area between Hurricane Dora passing well to the south and the surface ridge to the north will support damaging easterly winds and dry conditions into midweek. Guidance depicts the winds peaking today, then slowly easing into Wednesday. Peak wind gust observations overnight have hovered in the 45 to 55 MPH range across the state in the windier locations. In addition to the winds, very dry conditions will continue with humidities dipping into the 35 to 45 percent range this afternoon. The upper air soundings at Hilo and Lihue support this with very dry profiles along with a low inversion height (< 5000 ft). The inversion height may dip toward the 3000 ft mark this afternoon, which will only drive stronger wind speed accelerations due to a combination of island terrain and the peak mixing hours. For potential impacts regarding the dry conditions and winds, see the latest High Wind and Red Flag Warnings.
For the second half of the week, expect a more seasonable breezy trade wind pattern to return as the pressure gradient relaxes over the region and Dora continues westward and away from the area. More typical moisture levels will return to the state as well, with showers mainly focusing along windward and mauka areas, particularly during the overnight through morning hours each day.

Aviation

The pressure gradient continues to tighten across the state as strong high pressure resides north of the islands and Hurricane Dora passes by well to the south. Strong trades will persist through the forecast period and bring tempo moderate to severe low level turbulence to areas in the lee of mountains. Winds are forecast to peak in intensity late this morning through this afternoon.
The dry airmass will limit cloud and showers coverage through Wednesday.
AIRMET Tango remains in effect below 6000 feet over and immediately south through west of mountains and all islands for tempo moderate to isolated severe turbulence.

Marine

Hurricane Dora will continue on its westward track passing well south of the Hawaiian Islands, near gales to gale-force winds with high seas are expected through tonight. Winds will begin to decline on Wednesday into strong trade winds and more typical trade wind weather will return by Thursday. Seas will also rapidly build with a mix of short-period wind waves and longer period east-southeast swell from Hurricane Dora. Gale Warnings are in place for the windier waters around Maui County and the Big Island. A Small Craft Advisory is in effect for all remaining waters. Conditions are expected to steadily improve from Wednesday into Thursday with our typical strong trade winds returning by Thursday.
Surf along east facing shores will peak today due to a combination of very strong winds, large seas and a moderately sized, moderate period east-southeast swell generated from Dora. The largest surf is expected over the eastern end of the state, where surf heights will reach warning levels through the day across exposed east and southeast facing shores. A downward trend is expected later today through Thursday as trade winds and seas diminish to more typical conditions. A High Surf Warning remains in effect starting for all exposed east facing shores of the Big Island, Maui and Molokai. A High Surf Advisory remains in effect for east facing shores of Oahu and Kauai today.
Surf along south facing shores should see an increase today due to a combination of long period southwest swell and medium period southeast swell. Another long period south-southwest swell will arrive by Wednesday and will likely produce above average surf along south facing shores on Wednesday and Thursday, before diminishing through the end of the week.

Fire weather

Very dry fuels (KDBI around 600) combined with strong and gusty easterly winds and low humidities below 45 percent will produce critical fire weather conditions through tonight. See the Red Flag Warning for more information.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 AM HST Wednesday for Niihau, Olomana, Kauai East, Koolau Windward, Windward Haleakala, Kipahulu, Big Island East.
Red Flag Warning until 6 AM HST Wednesday for Kauai Leeward, Oahu South Shore, Waianae Coast, Oahu North Shore, Olomana, Central Oahu, Waianae Mountains, Molokai Leeward, Lanai Makai, Lanai Mauka, Maui Leeward West, Maui Central Valley, Leeward Haleakala, Kona, South Big Island, Kohala, Big Island Interior.
High Wind Warning until 6 AM HST Wednesday for Kauai Leeward, Kauai Mountains, Waianae Coast, Oahu North Shore, Central Oahu, Waianae Mountains, Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Haleakala Summit, Kohala, Big Island Interior, Big Island Summits, Kauai North, Kauai South, East Honolulu, Honolulu Metro, Ewa Plain, Koolau Leeward, Molokai, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, South Maui/Upcountry, South Haleakala, Big Island South, Big Island Southeast, Big Island North.
High Surf Advisory until 6 PM HST this evening for Olomana, Kauai East, East Honolulu, Koolau Windward.
High Surf Warning until 6 PM HST this evening for Maui Windward West, Molokai Windward, Molokai Southeast, Windward Haleakala, Kipahulu, Big Island Southeast, Big Island East, Big Island North.
Small Craft Advisory until 6 AM HST Wednesday 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.
Gale Warning until 6 AM HST Wednesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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Data Courtesy of NOAA.gov