Hilo

Today: Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the afternoon. Highs around 79 near the shore to 64 to 69 at 4000 feet. North winds 10 to 15 mph. Chance of rain near 100 percent.

Tonight: Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the evening. Lows around 63 near the shore to around 49 at 4000 feet. North winds 10 to 15 mph. Chance of rain near 100 percent.

Thursday: Occasional showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Highs around 79 near the shore to 64 to 69 at 4000 feet. Northeast winds 10 to 15 mph. Chance of rain near 100 percent.

Kona

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers and isolated thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 79 to 84 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers and isolated thunderstorms in the evening, then mostly clear after midnight. Locally heavy rainfall possible in the evening. Lows 63 to 68 near the shore to around 50 near 5000 feet. Light winds becoming east up to 10 mph after midnight. Chance of rain 50 percent.

Thursday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 79 to 84 near the shore to around 70 near 5000 feet. East winds around 10 mph shifting to the northwest in the afternoon. Chance of rain 50 percent.

Waimea

Today: Breezy. Numerous showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 78 near the shore to 70 to 77 near 3000 feet. East winds 10 to 25 mph with gusts to 45 mph. Chance of rain near 100 percent.

Tonight: Breezy. Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the evening. Lows around 62 near the shore to 48 to 56 near 3000 feet. East winds 10 to 25 mph with gusts to 50 mph. Chance of rain near 100 percent.

Thursday: Mostly cloudy. Breezy. Numerous showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Highs around 78 near the shore to 70 to 77 near 3000 feet. East winds 10 to 25 mph with gusts to 45 mph. Chance of rain 90 percent.

Kohala

Today: Breezy. Numerous showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 78 near the shore to 70 to 77 near 3000 feet. East winds 10 to 25 mph with gusts to 45 mph. Chance of rain near 100 percent.

Tonight: Breezy. Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the evening. Lows around 62 near the shore to 48 to 56 near 3000 feet. East winds 10 to 25 mph with gusts to 50 mph. Chance of rain near 100 percent.

Thursday: Mostly cloudy. Breezy. Numerous showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Highs around 78 near the shore to 70 to 77 near 3000 feet. East winds 10 to 25 mph with gusts to 45 mph. Chance of rain 90 percent.

South Big Island

Today: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers and isolated thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Mostly clear. Breezy. Isolated showers and thunderstorms in the evening. Locally heavy rainfall possible in the evening. Lows around 65 near the shore to around 49 near 5000 feet. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Thursday: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

Puna

Today: Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the afternoon. Highs around 79 near the shore to 64 to 69 at 4000 feet. North winds 10 to 15 mph. Chance of rain near 100 percent.

Tonight: Occasional showers and isolated thunderstorms. Locally heavy rainfall possible in the evening. Lows around 63 near the shore to around 49 at 4000 feet. North winds 10 to 15 mph. Chance of rain near 100 percent.

Thursday: Occasional showers in the morning, then occasional showers and isolated thunderstorms in the afternoon. Highs around 79 near the shore to 64 to 69 at 4000 feet. Northeast winds 10 to 15 mph. Chance of rain near 100 percent.

Waikoloa

Today: Windy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers and isolated thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 81 near the shore to 65 to 72 above 4000 feet. East winds up to 30 mph with gusts to 50 mph. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with scattered showers and isolated thunderstorms in the evening, then partly cloudy with isolated showers after midnight. Locally heavy rainfall possible in the evening. Lows around 67 near the shore to 45 to 53 above 4000 feet. East winds up to 30 mph increasing to 10 to 30 mph after midnight. Gusts up to 50 mph. Chance of rain 50 percent.

Thursday: Breezy. Mostly sunny with isolated showers. Highs around 81 near the shore to 65 to 72 above 4000 feet. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A wet trade wind pattern with isolated thunderstorms and locally heavy rain, especially over windward areas, will prevail through Wednesday night. Breezy to locally windy trade winds are expected over the next several days.

Discussion

Have made a few changes to the forecast with the morning package. The Winter Storm Warning for the Big Island summits has been cancelled, but a Winter Weather Advisory has been posted. A Wind Advisory for the lower elevations of Maui County and the Big Island has been issued for today.
Satellite shows a decrease in clouds over and immediately upstream of the Big Island this morning, but additional clouds are found about 50 miles to the east. Meanwhile a few more showers have been observed over the windward sides of Maui County and Oahu over the last few hours. PoP and associated grids have been adjusted accordingly.
Webcams on the Mauna Kea on the Big Island show clear skies overhead. While the day is expected to start clear, temperatures remain below freezing and are only expected to get a few degrees above freezing today. As the above mentioned moisture moves in later this morning/early afternoon, there remains a possibility for additional freezing rain, and even for some snow. Not expecting significant amounts, but enough to exercise caution. As a result, the Winter Storm Warning was cancelled, and a Winter Weather Advisory was issued through tomorrow afternoon.
Winds over the lower elevations are expected to once again reach Wind Advisory criteria today over portions of the lower elevations of Maui County and the Big Island. As such, have issued a Wind Advisory that will be in effect from 8am this morning, and persist through the evening hours. The areas most likely to experience the advisory levels winds will over passes, through gaps, and downslopes of mountains.
Synoptically not much has changed. Strengthening high pressure to the north will help to boost trade winds today. maintain the locally windy trade winds today. A new high moving in from the west will replace the existing high tomorrow, and as a result, trades will continue, but should be back to moderate levels. Those trades will continue into next week.
The upper levels continue to be driving the wetter pattern. The upper level trough axis remains oriented northeast to southwest near Kauai, with its associated broad mid level trough over the main Hawaiian islands. There is good model agreement with another area of moisture riding in on the trades later today. As this moisture encounters colder than normal 500 mb temperatures (near -15 C near Kauai and near -12 C the Big Island) there will be another chance for thunderstorms. This area of moisture is expected to move through tonight for another round of wetter weather. Previously felt the focus for this would Maui County and the Big Island, however the latest guidance shows the moisture making its way northward to Oahu as well.
Heading into tomorrow, the large scale pattern undergoes little in the way of change, but deeper troughing west of the islands will pump up heights locally which should help bring an end to the current wet trade wind pattern. A more typical breezy to locally strong trade wind pattern then prevails heading into the weekend.

Aviation

A strong high pressure system north of the islands will keep moderate to locally windy trade wind weather pattern. An upper level trough will produce windward and mountain showers with periods of MVFR conditions. Stronger showers may drift into leeward areas mainly in the overnight to early morning hours. Isolated thunderstorms remain in the forecast through Thursday.
AIRMET Sierra remains in effect for Tempo Mountain Obscurations along north though east slopes of Oahu, Molokai, Maui and the Big Island. This AIRMET will likely decrease in coverage later this morning.
AIRMET Tango remains in effect for moderate mountain wave turbulence over all islands due to breezy to locally windy trade winds. This AIRMET will likely continue through much of this week.

Marine

A large area of high pressure centered approximately 800 nautical miles north of Oahu will slowly move east the next couple of days. This will continue to support a tight enough pressure gradient down across the state to result in strong to near gale force trade winds over the majority of the Hawaiian nearshore waters through the remainder of the week. Late week high pressure moving in from the west will build in the wake of the current high and establish itself north of the islands by Friday. This will maintain persistent strong trades through the weekend. The ongoing all-water Small Craft Advisory will be in effect the next several days. An upper level trough positioned over the state will keep the regional atmosphere unstable the next couple of days. There is a decent probability for brief periods of heavy showers and isolated thunderstorms, especially in windward waters, that may produce strong wind gusts and lower visibilities. The threat for more active weather will diminish Friday in response to a weakening trough.
Persistent fresh to strong trades will continue to generate rough, choppy surf along east-facing shores through the week. Despite these very rough conditions, east surf is expected to remain under High Surf Advisory heights. A small, medium period northwest (310 degree) swell will quickly pass around the island chain today. A bit larger, slightly longer period northwest (320-330 degree) swell is scheduled to arrive late Friday into Saturday. This swell will likely peak north-facing shore surf to double overhead.

HFO Watches/Warnings/Advisories

Wind Advisory from 8 AM this morning to 8 PM HST this evening for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Kohala, Big Island Interior, Molokai, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, Windward Haleakala, Kipahulu, South Maui/Upcountry, South Haleakala, Big Island South, Big Island Southeast, Big Island North.
Winter Weather Advisory until 6 PM HST Thursday for Big Island Summits.
Small Craft Advisory until 6 AM HST Friday for all Hawaiian waters,

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Data Courtesy of NOAA.gov