Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to around 70 above 3000 feet. East winds up to 10 mph shifting to the southwest around 10 mph in the afternoon. Chance of rain 30 percent.

Tonight: Partly cloudy with scattered showers. Lows around 66 near the shore to around 55 above 3000 feet. Southwest winds up to 10 mph. Chance of rain 30 percent.

Saturday: Breezy. Mostly sunny with scattered showers. Highs around 83 near the shore to around 71 above 3000 feet. Southwest winds 10 to 20 mph. Chance of rain 30 percent.

South Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 81. West winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with scattered showers. Lows 62 to 67. West winds 10 to 15 mph. Chance of rain 30 percent.

Saturday: Breezy. Mostly sunny with scattered showers. Highs around 82. West winds 10 to 20 mph. Chance of rain 30 percent.

Kaua’i Mountains

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 69 to 77 in the valleys to around 64 above 4000 feet. Southwest winds up to 15 mph. Chance of rain 30 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows 55 to 60 in the valleys to around 49 above 4000 feet. Southwest winds up to 20 mph. Chance of rain 30 percent.

Saturday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 70 to 78 in the valleys to around 65 above 4000 feet. Southwest winds up to 25 mph with gusts to 45 mph. Chance of rain 30 percent.

North Kaua’i

Today: Partly sunny with isolated showers. Highs 74 to 81. South winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 58 to 67. South winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 75 to 82. South winds up to 15 mph shifting to the west in the afternoon. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny. Isolated showers in the afternoon. Highs 74 to 81. Southwest winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 56 to 68. Southwest winds up to 15 mph. Chance of rain 30 percent.

Saturday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 82. Southwest winds up to 20 mph. Chance of rain 30 percent.

Detailed Forecast

Synopsis

Rather dry weather will prevail today through the weekend, with only a few showers possible near the leeward coasts at night and over the island interiors each afternoon. Light winds will gradually increase out the southwest late today and tonight, with moderate southwesterlies then holding through the weekend. Rain chances will increase and breezy southwest winds will develop Sunday night and Monday as a front approaches from the northwest. The front will bring some showery weather as it pushes slowly eastward down the island chain Monday night through middle of next week, with winds gradually easing to light and variable levels.

Discussion

Currently at the surface, a weakening front is located northeast of the state, with a trailing moisture band lingering in the vicinity of Maui and the Big Island. Meanwhile, a surface ridge axis is positioned just south of the Big Island. Light winds prevail with land breezes present across the entire island chain. Infrared satellite imagery shows partly to mostly cloudy conditions across the state. Meanwhile, radar imagery shows isolated to scattered showers moving into leeward portions of the smaller islands. Main short term focus revolves around rainfall and wind trends during the next couple days.
The surface ridge axis south of the state will settle a bit further south today through the weekend, as a front approaches from the northwest. Southwest winds will increase to moderate levels across the western islands late today and tonight, with moderate southwesterlies overspreading the remainder of the state on Saturday. Winds will then change little Saturday night and Sunday as the front stalls out a couple hundred miles northwest of Kauai, then increase to breezy levels Sunday night and Monday as a new front moves in from the northwest. The front will then slowly shift eastward across the state Monday night and Tuesday easing the southwest winds, then stall out and dissipating Wednesday and Thursday, resulting in light winds across the state.
As for the remaining weather details, rather dry weather will continue across the state through the weekend. As the moisture band meanders through the smaller islands however, a few showers will affect areas near the leeward coasts at night, with a few showers possible over the island interiors each afternoon as well. A better shot for some rainfall will develop in advance of a front Sunday night and Monday, with the higher rain chances then spreading down the island chain as the front propagates slowly eastward Monday night through the middle of next week.

Aviation

A few bands of clouds and showers continue to develop across the state this morning. Light to moderate southwesterly winds will continue to blow across the state today with afternoon sea breezes along terrain sheltered north and east slopes. Mostly dry weather conditions will continue with prevailing VFR conditions.
No AIRMETs in effect and none are expected.

Marine

Prevailing southwest to west winds through the weekend are expected as the subtropical ridge will remain south of the islands. Another front slowly approaching from the northwest will bring moderate to fresh south to southwest winds into early next week. This front may move over the islands Monday night and Tuesday, potentially followed by a brief period of trade winds by the middle of next week.
Declining moderate medium period west-northwest swell has dropped below just below High Surf Advisory (HSA) levels this morning. Associated seas have also dropped below 10 feet for all coastal waters as the Small Craft Advisory (SCA) has been cancelled too.
Another WNW swell will arrive Sunday and Monday into the HSA- level surf along select north and west facing shores, and may impact leeward Big Island as well. Another storm is currently developing in the far northwest Pacific and is forecasted to track eastward and merge with the low that will produce this weekends swell. As a result, a large to extra-large long period west- northwest swell is expected Tuesday and could push surf heights to High Surf Warning levels.
Short-period choppy wind waves along south and west facing shores will ease as winds trend down today, but will likely redevelop again over the weekend as southwest winds increase again. Surf along east facing shores will remain small due to the lack of easterly trade winds. Surf along south facing shores will remain small except for areas exposed to the west wrap.

HFO Watches/Warnings/Advisories

High Wind Warning until 6 PM HST this evening for Big Island Summits.

Data Courtesy of NOAA.gov