Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Sunny. Isolated showers in the afternoon. Highs around 89 near the shore to around 77 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 69 to 74 near the shore to around 60 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny with isolated showers. Highs around 87 near the shore to around 75 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 86. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 67 to 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 84. East winds 10 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 76 to 83 in the valleys to around 67 above 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows 60 to 65 in the valleys to around 55 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Thursday: Mostly cloudy. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 74 to 81 in the valleys to around 65 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 79 to 88. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers 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 77 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 79 to 87. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 61 to 74. Northeast 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 77 to 85. East winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Trade winds will ease slightly today and tomorrow, then remain at moderate speeds through the weekend. Low clouds and passing showers will favor windward and mountain areas, especially night and morning. Leeward Big Island will see afternoon and evening clouds that will clear during nights and mornings.

Discussion

A persistent high pressure ridge N of the islands will weaken somewhat through tomorrow, allowing trade wind speeds to moderate. Trades will likely continue to be locally breezy in the typically windy areas during the afternoons, but overall speeds will be moderate through the weekend. Some increase in trade wind speeds is possible early next week as the ridge strengthens.
The trades will deliver randomly distributed low cloud clusters, occasionally delivering some showers, mainly to windward areas. The island atmosphere will remain stable, thus heavy showers are not expected. Afternoon heating of leeward Big Island slopes will lead to typical cloud and shower development that will persist through the evening hours before clearing late at night.

Aviation

Breezy trade winds will start to gradually weaken today. A band of unstable showers moving into the Big Island and Maui, will drift westward, increasing cloud and shower trends across the Hawaiian Islands through the evening hours.
Mostly VFR conditions will prevail with periods of MVFR conditions in showers mainly along northern and eastern slopes of each island. Stronger showers will drift into leeward areas later today with these unstable clouds.
AIRMET Sierra remains in effect for mountain obscurations over north through east sections of Maui and the Big Island this morning. These conditions may continue through the evening hours.
AIRMET Tango will remain in place for moderate low level turbulence over and south through west of all island mountains. This AIRMET will likely continue at least through the morning hours.

Marine

The strong ridge north of the state that has been delivering the gusty easterly trades over the past several days will gradually weaken today through the second half of the week. Expect the local winds to respond and begin to ease from the fresh to strong category to the moderate to fresh range with localized pockets of strong winds potentially continuing. As a result, no changes are anticipated at this time to the current Small Craft Advisory in place for the the typically windier waters between Maui County and the Big Island.
Surf along south facing shores will steadily lower through Thursday as the south-southeast swell that has been impacting the area since Saturday continues to ease. Early morning observations at the offshore/nearshore buoys to the south reflect this trend with the peak energy now down into the 12-15 second bands. Surf heights will respond and steadily lower today, then return to the typical summertime levels late Thursday through the weekend. For the long range (next week), mainly background swells from the south and south- southwest (Tasman sources) are expected.
Surf along east facing shores will gradually lower through the second half of the week as the trades ease locally and upstream across the eastern Pacific.
Surf along north and west facing shores will remain near the summertime average each day with mainly background north-northwest swell moving through.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov