Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny. Breezy. Scattered showers in the morning. Highs around 87 near the shore to around 77 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows 70 to 75 near the shore to around 61 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Breezy. Mostly sunny with isolated showers. Highs around 87 near the shore to around 77 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny. Breezy. Scattered showers in the morning. Highs around 86. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 68 to 74. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Friday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 86. Northeast winds 15 to 25 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Mostly cloudy. Breezy. Showers likely in the morning, then isolated showers in the afternoon. Highs 73 to 81 in the valleys to around 70 above 4000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then frequent showers after midnight. Lows 61 to 66 in the valleys to around 56 above 4000 feet. East winds up to 25 mph. Chance of rain 80 percent.

Friday: Mostly cloudy. Breezy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 73 to 81 in the valleys to around 70 above 4000 feet. East winds up to 20 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 80 percent.

North Kaua’i

Today: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 76 to 86. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 64 to 74. East winds up to 20 mph. Chance of rain 70 percent.

Friday: Breezy. Partly sunny with scattered showers. Highs 76 to 86. East winds up to 20 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 86. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 62 to 75. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

Friday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 86. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Strong trade winds will persist into early next week, bringing brief showers to windward and mauka areas. There's a potential for increased windward shower coverage tonight through Friday due to an approaching weak upper disturbance from the east.

Discussion

The surface ridge is expected to strengthen gradually over the next few days, typically strengthening the trade winds locally. However, an approaching mid- to upper-level trough could temporarily weaken these winds later today through Friday. Prior to this, there remains the possibility of a short-fused wind advisory for lower elevations in the typical windier locations of Maui County and the Big Island through the day. Strong northeast winds at the Big Island Summits are holding early this morning due to a tight pressure gradient aloft, but have begun to trend down. That trend will should continue as the upper trough moves through. This trough could also weaken the strong subsidence inversion, potentially increasing windward shower activity tonight through Friday, with some showers reaching the dry leeward areas of the smaller islands.
Guidance suggests seasonable trade wind conditions continuing this weekend through early next week, with the ridge remaining strong to the north. The strong trades could ease slightly later next week as the ridge weakens. Showers will favor the typical windward areas, with minimal accumulations expected.

Aviation

Windy trade winds will continue for the next couple of days, with passing showers favoring windward and mauka areas. Expect mainly VFR, with brief MVFR in showers/low clouds.
AIRMET Sierra for tempo mountain obscuration remains in effect for most windward areas.
AIRMET Tango for low-level mountain lee turbulence will remain in effect for the next several days due to the strong trades. May also need AIRMET Tango for strong surface winds greater than 30 kt this afternoon.

Marine

Strong- to near gale-force east to northeast trades with seas up to the 10 ft advisory level will continue through early next week as the ridge holds strong to the north. The strong trades could ease slightly later next week as the ridge weakens.
Surf along east facing shores will remain rough through early next week due to the strong trades locally and upstream of the state. A downward trend is possible next week as the upstream fetch weakens and the local trades begin to ease around midweek.
Surf along south facing shores will remain up as overlapping south-southwest swells move through. After a brief down trend today, a fresh south-southwest pulse arriving Friday will result in an upward trend going into the weekend. A more significant south swell will gradually fill in late Saturday night into Sunday, then likely reach the advisory level late Sunday through Monday. A gradual downward trend is expected Tuesday through midweek.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Friday for all Hawaiian waters,

Data Courtesy of NOAA.gov