West Kaua’i

Tonight: Partly cloudy with isolated showers. Lows around 73 near the shore to around 62 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Thursday: Breezy. Sunny with isolated showers. Highs 85 to 91 near the shore to around 76 above 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly clear with isolated showers. Lows around 74 near the shore to around 62 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 71 to 77. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 79 to 89. East winds 10 to 20 mph. Chance of rain 50 percent.

Thursday Night: Breezy. Mostly cloudy with scattered showers. Lows 71 to 78. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 68 in the valleys to around 60 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 73 to 81 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Thursday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows around 68 in the valleys to around 61 above 4000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

North Kaua’i

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 64 to 75. East winds up to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny with scattered showers. Highs 70 to 86. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Thursday Night: Partly cloudy with scattered showers. Lows 64 to 75. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 67 to 77. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 76 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 67 to 78. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds will strengthen through the week and deliver periodic showers to windward and mountain areas.

Discussion

Radar and satellite imagery show drier air gradually filtering across the state from east to west this afternoon, with the greatest focus over Kauai. In fact, Kauai has been the main focus for rainfall across the state in the short term, with 12-hour rainfall totals ranging generally between 1 and almost 5 inches across the typical wetter areas.
High pressure to the far northeast will gradually move southwestward over the next couple of days and strengthen. This will allow the moderate to breezy trades felt across the state today to strengthen over the second half of the week. Minor batches of moisture will filter in on the trade wind flow, bringing periodic upticks in windward and mauka showers through the weekend, particularly during the overnight to early morning hours.
Next week, the weather across the state will depend on the eventual track and intensity of Tropical Cyclone Fausto. The National Hurricane Center is forecasting a gradual weakening of this system as it tracks westward and enters into the Central Pacific this weekend, with further weakening expected early next week as it moves into a more hostile environment with cooler waters and increased shear. At this time, its too early to predict any direct impacts from Fausto on Hawaii, though confidence is increasing in east-facing shores receiving a decent swell late this weekend into early next week. See the marine discussion below for more details.

Aviation

Clouds and showers have lingered over the western end of the state, with Oahu only clearing out around 2pm. AIRMET Sierra for mountain obscuration over Kauai remains in place due to the lingering clouds and showers. VFR conditions are largely expected elsewhere.
Moderate trade winds will continue, with the clouds and showers being carried in on the trade wind flow. Not expecting additional AIRMETs, however the trade winds could cause some mechanical turbulence to the lee of the mountains at times.

Marine

High pressure far northeast of the state will maintain fresh to locally strong trades through tonight, for which a Small Craft Advisory (SCA) remains in effect for the typical windier channels and waters around Maui and the Big Island for the strengthening trade winds. Trades are expected to strengthen another notch Thursday into Friday, which has prompted an expansion of the SCA to all Hawaiian Waters for Thursday and Thursday night. Widespread fresh to strong winds are expected during this time with near gales possible for the windier waters around Maui County and the Big Island. The strong high to the north is expected to eventually shift westward and weaken some, which should allow the trade winds to weaken a notch around Sunday. Trends in the strength and direction of winds early next week become less clear as a result of the uncertain track of a weakening Hurricane Fausto (forecast to become a tropical storm by Monday) in the central Pacific.
The current medium-period south-southeast swell producing above average surf along south-facing shores will continue to gradually fade over the next few days. Offshore buoys are showing an increase in energy over 20 second periods as forerunners from the next notable incoming south swell slowly fill in tonight. A High Surf Advisory (HSA) has been issued from 6 am Thursday as surf is expected to increase to advisory levels through the day on Thursday. There is also potential to approach warning levels late Thursday into Friday as the swell peaks. Over the weekend, reinforcing long-period swell energy may allow advisory level surf to persist and may require an extension of the HSA.
Surf along east-facing shores will remain slightly below seasonal levels through the evening due to the weaker trades upstream of the islands. The Hilo buoy continues to show a small, medium- period east swell this evening, which was likely generated by former TC Elida. Stronger trade winds will also support an increase of short-period energy heading into Thursday and Friday. This weekend, larger surf generated by Hurricane Fausto is possible and could bring advisory level surf along east facing shores.
Surf along north-facing shores will remain at flat to tiny levels through the weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory from 6 AM Thursday to 6 AM HST Friday for Big Island South, Big Island Southeast, East Honolulu, Ewa Plain, Honolulu Metro, Kahoolawe, Kauai South, Kauai Southwest, Kona, Lanai Leeward, Lanai South, Maui Central Valley South, Maui Leeward West, Molokai Leeward South, Niihau, South Haleakala, South Maui/Upcountry, Waianae Coast.
Small Craft Advisory from 6 AM Thursday to 6 AM HST Friday for Big Island Windward Waters, Kaiwi Channel, Kauai Channel, Kauai Leeward Waters, Kauai Northwest Waters, Kauai Windward Waters, Maui County Leeward Waters, Maui County Windward Waters, Oahu Leeward Waters, Oahu Windward Waters.
Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Maalaea Bay, Pailolo Channel.

Kauai Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Kaua‘i Helicopter Tours today!

Data Courtesy of NOAA.gov