Photo Credit: Brendan Stephen

West Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 86 near the shore to around 74 above 3000 feet. East winds up to 15 mph becoming around 10 mph in the afternoon. Chance of rain 40 percent.

Tonight: Mostly clear with isolated showers. Lows 69 to 74 near the shore to around 60 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Thursday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 87 near the shore to around 74 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Kaua’i

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 81 to 86. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 67 to 74. Northeast winds around 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 82 to 87. East winds around 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Mostly cloudy. Occasional showers in the morning, then scattered showers in the afternoon. Highs 73 to 80 in the valleys to around 64 above 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 90 percent.

Tonight: Mostly cloudy with showers likely. Lows 61 to 66 in the valleys to around 55 above 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 73 to 80 in the valleys to around 64 above 4000 feet. East winds 15 to 20 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny with showers likely in the morning, then mostly sunny with scattered showers in the afternoon. Highs 76 to 85. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. Lows 63 to 73. East winds 10 to 15 mph. Chance of rain 70 percent.

Thursday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 76 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy with showers likely in the morning, then mostly sunny with scattered showers in the afternoon. Highs 76 to 84. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. Lows 61 to 75. East winds 10 to 15 mph. Chance of rain 70 percent.

Thursday: Mostly cloudy with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 76 to 85. East winds around 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Trade winds will strengthen today and Thursday, becoming locally breezy. Trade winds may become locally strong over the weekend before easing somewhat early next week. Windward showers will be brief, favoring nights and mornings, while leeward Big Island will see clouds and showers during the afternoons and evenings.

Discussion

The summer solstice will occur at 458 AM HST this morning, marking the official start of summer. Island weather will be seasonable, especially as trade winds strengthen today and Thursday in response to high pressure building N of the area. Breezy trade winds may become locally strong over the weekend before moderating somewhat early next week.
The island atmosphere will become increasingly stable as a departing low aloft allows a mid-level ridge to build overhead. Any showers that arrive on the trade flow will favor windward areas during nights and mornings, with little in the way of total accumulation. Leeward Big Island will see their typical afternoon and evening clouds and showers that linger well into the night before clearing by morning.

Aviation

Trade winds will gradually strengthen today, with locally breezy conditions expected across much of the state by this afternoon. Showers will favor windward and mauka areas, with a few showers spilling leeward from time to time.
No AIRMETs are in effect. AIRMET Sierra may be needed for mountain obscuration on Kauai later this morning. AIRMET Tango may be needed for low level turbulence over and downwind of the terrain of all islands this afternoon.

Marine

Fresh to strong trades have returned and will persist through the upcoming weekend. Seas will quickly respond and become rough over the exposed waters, especially over the windier waters and channels. As a result, a Small Craft Advisory is now in effect for the typically windier waters and channels between Molokai and the Big Island, and may need to be expanded to other waters this weekend.
Surf along north and west facing shores will return to near summertime levels through the second half of the week and upcoming weekend. For the long-range, guidance does show a small northwest (320-330 deg) swell arriving late Sunday through early next week from a gale that is currently located over the far northwest Pacific.
Surf along east facing shores will trend up Thursday through the weekend as the local and upstream trades return to fresh/strong levels.
Surf along south facing shores will remain small each day through Friday with mainly background southerly swell energy moving through. Although high pressure is currently parked in our typical swell window southeast of New Zealand, a powerful gale- to storm-force low that has been pulsing over the past few days far south of the Tuamotus and Tahiti will generate a long-period south-southeast (165- 175 deg) swell, that should arrive Friday night and be fully filled in by the end of Saturday, driving surf heights above the summertime average. Expect this to linger well into next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Friday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov