Hilo

Tonight: Mostly cloudy with scattered showers. Lows 57 to 64 near the shore to 46 to 52 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 81 near the shore to 62 to 68 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 58 to 65 near the shore to 48 to 54 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Kona

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 67 near the shore to 41 to 47 near 5000 feet. Light winds. Chance of rain 20 percent.

Friday: Sunny. Isolated showers in the afternoon. Highs 80 to 85 near the shore to around 67 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Friday Night: Mostly clear. Isolated showers in the evening. Lows around 68 near the shore to 43 to 49 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny with isolated showers. Highs 61 to 80. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 58 to 67 near the shore to 50 to 57 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 57 to 66 near the shore to 49 to 56 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny with isolated showers. Highs 61 to 80. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 58 to 67 near the shore to 50 to 57 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

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

Friday: Sunny. Highs around 83 near the shore to around 66 near 5000 feet. Northeast winds 10 to 15 mph shifting to the east in the afternoon.

Friday Night: Partly cloudy in the evening then becoming clear. Lows around 69 near the shore to around 48 near 5000 feet. Northeast winds 10 to 15 mph.

Puna

Tonight: Mostly cloudy with scattered showers. Lows 57 to 64 near the shore to 46 to 52 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 81 near the shore to 62 to 68 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 58 to 65 near the shore to 48 to 54 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Waikoloa

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

Friday: Sunny. Highs 80 to 86 near the shore to 63 to 70 above 4000 feet. Northeast winds up to 10 mph shifting to the north in the afternoon.

Friday Night: Mostly clear. Lows 66 to 71 near the shore to around 49 above 4000 feet. Southeast winds up to 15 mph.

Detailed Forecast

Synopsis

Moderate to locally fresh trade winds continue through tonight before weakening Friday through the first half of next week. Conditions remain fairly stable with passing low clouds and light showers.

Discussion

High pressure far north-northeast will drive moderate to locally fresh trade winds across the islands through tonight. Visible satellite shows an area of incoming low clouds to windward Big Island that could bring a some showers over windward slopes tonight. Scattered clouds across the smaller islands may also bring a few showers mainly to windward slopes. 00Z soundings show a dry and stable atmosphere across the state, so any showers that do move onto the islands will be light.
Trade wind speeds will weaken Friday into the weekend as a front approaches then stalls and weakens northwest of Kauai. Expect mostly dry and stable weather to continue Friday and Saturday with the highest chance of rain along windward slopes during the nighttime and early morning hours. Winds will shift out of the south by Sunday, but will weaken enough for localized daytime sea breezes and nighttime land breezes Sunday into Monday. Clouds and showers will focus over leeward and interior sections during the afternoons due to the sea breezes setting up.
A stronger front will approach and begin is forecast to reach Kauai around Thursday then either stall in place or slowly moving across the state into Friday. Winds will strengthen out of the south and southwest beginning Sunday night across Kauai and Oahu, but remain mostly in the land and sea breezes pattern over Maui County and the Big Island. A shower band ahead of the front will make its way through the southerly flow by Wednesday and may impact Kauai and/or Oahu into Wednesday night. The front will arrive on Kauai Thursday in a fairly weak state before stalling out and dissipating over the central part of the state next weekend. Still some model differences with the with the timing and location of the front as it reaches Hawaii.

Aviation

Moderate trades will continue through tomorrow. Shower activity will remain minimal with strong atmospheric stability in place. However, a band of moisture riding in on the trades may bring a slight uptick in showers this evening. Overall, VFR conditions will prevail.
No AIRMETs are in effect and none are anticipated to be needed through tomorrow.

Marine

Moderate to fresh northeast winds will hold into Friday. A Small Craft Advisory is currently in effect through tonight for the Alenuihaha channel. Winds should ease over the weekend when a weak front is expected to approach then stall to the northwest of Kauai.
A large to extra large long-period west-northwest swell will build in late tonight and drive surf heights to High Surf Warning levels along exposed north and west facing shores Friday into Saturday. Additionally, due to the strong westerly component of this swell, west-facing Big Island surf will likely reach High Surf Advisory (HSA) criteria of 8 feet as early as Friday afternoon.
This long period northwest swell is expected to be at its peak late Friday night or early Saturday then gradually decline. A Small Craft Advisory will be issued for seas greater than 10 ft in the majority of the coastal waters Friday and Saturday. There is also the potential for brief overtopping of vulnerable coastal roadways and some wave runup to coastal properties around high tide early Saturday morning.
Surf along east and northeast facing shores will remain elevated through the weekend due to the lingering short-period north- northeast swell. Surf along south facing shores will remain near seasonal averages for the rest of this week, driven by a mix of short-period southeast and background long period south-southwest swells. An upward trend is expected this weekend through the first week of December, due to an active pattern evolving within our swell window near New Zealand.

Fire weather

Critical fire weather conditions not expected through early next week as winds remain below warning thresholds. Daytime relative humidity may briefly touch critical levels over drier leeward zones into next week.

HFO Watches/Warnings/Advisories

High Surf Warning from 6 AM Friday to noon HST Saturday for north and west facing shores of Niihau, Kauai, Oahu, Molokai and for north facing shores of Maui.
High Surf Advisory from noon Friday to noon HST Saturday for west facing shores of Big Island.
Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel.
Small Craft Advisory from 6 AM Friday to 6 PM HST Saturday 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