Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Sunny. Isolated showers in the afternoon. Highs 86 to 92 near the shore to around 77 above 3000 feet. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds up to 10 mph increasing to 10 to 15 mph after midnight.

Saturday: Sunny and breezy. Highs around 89 near the shore to around 76 above 3000 feet. East winds 10 to 20 mph.

South Kaua’i

Today: Sunny. Highs 85 to 92. Northeast winds around 10 mph.

Tonight: Partly cloudy. Scattered showers after midnight. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Saturday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 84 to 91. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Sunny. Isolated showers in the afternoon. Highs 76 to 83 in the valleys to around 69 above 4000 feet. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 65 to 71 in the valleys to around 60 above 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 40 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 75 to 84 in the valleys to around 67 above 4000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

North Kaua’i

Today: Sunny. Isolated showers in the afternoon. Highs 79 to 88. Light winds becoming northeast up to 15 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 66 to 74. East winds up to 10 mph. Chance of rain 30 percent.

Saturday: Sunny. Isolated showers in the morning. Highs 78 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

East Kaua’i

Today: Sunny. Isolated showers in the afternoon. Highs 78 to 88. Light winds becoming northeast around 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 66 to 77. Northeast winds around 10 mph. Chance of rain 40 percent.

Saturday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 76 to 87. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Detailed Forecast

Synopsis

Trade winds will gradually strengthen today, becoming breezy this weekend as a strong high builds far northwest of the islands. An approaching front may increase shower coverage for portions of the island chain early next week, with the best chance of enhanced showers on Kauai.

Discussion

A ridge just north of Kauai keeps winds light and variable across the western end of the state this morning, while light to moderate southeasterly winds prevail over the eastern half. Overnight land breezes cleared cloud cover generated by sea breezes yesterday afternoon, leaving scattered low clouds to clear skies everywhere except across southeast slopes of the Big Island. Total rainfall was minimal overnight. Our airmass remains rather dry and stable, with latest soundings showing about 1.2 inches of PW and positive lifted index values. Sharp inversions in the 4500 and 5500 feet layer limit vertical cloud development and rainfall potential.
Models show the ridge north of Kauai will rebound northward, allowing trade winds to build back in across the islands. Winds will still be light enough to allow development of sea breezes across sheltered locations today, but locally breezy trades will return statewide by Saturday and continue to strengthen through the rest of the weekend. Expect a gradual trend toward a typical distribution of trade wind clouds and showers favoring windward and mauka areas. A front will approach Kauai from the north early next week. An associated band of moisture looks likely to increase showers across windward and mountain areas of Kauai from Monday though mid-week.

Aviation

Light and variable winds are giving way to weak trades from east to west across the state early this morning. This flow is helping to bring some clouds and light showers mainly to windward areas this morning. Even with winds expected to gradually increase today, some local sea breezes will still be possible in the afternoon, mostly in protected leeward areas. Trades will continue to strengthen overnight into Saturday, bringing more clouds and showers across windward areas. VFR conditions will generally prevail, except for in passing showers where periodic MVFR conditions will be possible.
No AIRMETs are currently in effect and none are expected to be needed today or tonight.

Marine

Light winds this morning will gradually give way to returning trades this afternoon as a new strong high begins to build to the distant northwest. The trades are then expected to strengthen to fresh and locally strong levels tonight and Saturday, and a Small Craft Advisory may be needed for the typically windy waters around the Big Island and Maui as early as tonight. Advisory level winds will likely expand to additional waters Sunday through Tuesday as the building high strengthens the trade winds further.
The current north-northwest swell will get reinforced by a new moderate sized north-northwest swell late today through Saturday, with the next reinforcement due in late Sunday through Monday. North shore surf will then slowly decline Monday night through Thursday, with a small medium-period swell possibly moving in around next Friday. North shore surf will remain well below seasonal levels during the next 7 days.
The current small south-southwest will get reinforced by a new small south-southwest swell later today, keeping small surf in place along south facing shores through the weekend. South shore surf is then forecast to trend back closer to background levels by the middle to latter part of next week.
Surf along east facing shores will trend up over the weekend and then hold at or above normal levels through much of next week due to the strong trades over and upstream of the islands.

Fire weather

Trade winds will build back into the region beginning today, becoming breezy and gusty by Saturday. With a front stalling north of Kauai over the next few days, most islands will be rather dry with limited showers, especially during afternoons. A combination of afternoon relative humidity values below 50% in some leeward locations, expected gusty winds, and KBDI values above 690 increases concerns about the potential for hazardous fire weather conditions this weekend into early next week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov