Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Breezy. Mostly cloudy with scattered showers. Highs around 82 near the shore to around 68 above 3000 feet. Northeast winds up to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 67 near the shore to around 58 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 40 percent.

Friday: Mostly cloudy with isolated showers in the morning, then mostly sunny in the afternoon. Highs around 83 near the shore to around 70 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Cloudy with occasional showers in the morning, then partly sunny with showers likely in the afternoon. Highs 76 to 82. Northeast winds 20 to 25 mph. Chance of rain 90 percent.

Tonight: Breezy. Cloudy with showers likely. Lows around 68. Northeast winds 15 to 25 mph. Chance of rain 70 percent.

Friday: Breezy. Mostly cloudy with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 78 to 84. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Breezy. Occasional showers. Highs 69 to 76 in the valleys to around 60 above 4000 feet. East winds 10 to 25 mph decreasing to up to 25 mph in the afternoon. Chance of rain near 100 percent.

Tonight: Breezy. Cloudy with occasional showers. Lows 60 to 66 in the valleys to around 56 above 4000 feet. East winds up to 20 mph. Chance of rain 90 percent.

Friday: Breezy. Partly sunny with scattered showers. Highs 70 to 77 in the valleys to around 61 above 4000 feet. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Today: Breezy. Cloudy with occasional showers in the morning, then partly sunny with showers likely in the afternoon. Highs 71 to 81. East winds 10 to 20 mph. Chance of rain 90 percent.

Tonight: Breezy. Mostly cloudy with occasional showers. Lows 61 to 70. East winds up to 20 mph. Chance of rain 90 percent.

Friday: Partly sunny. Breezy. Showers likely in the morning, then isolated showers in the afternoon. Highs 72 to 82. East winds 10 to 20 mph. Chance of rain 70 percent.

East Kaua’i

Today: Breezy. Occasional showers. Highs 67 to 80. Northeast winds 10 to 20 mph. Chance of rain near 100 percent.

Tonight: Cloudy with occasional showers. Lows 61 to 72. Northeast winds 10 to 15 mph. Chance of rain 90 percent.

Friday: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 70 to 80. Northeast winds around 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

A wet and breezy trade wind pattern will persist through Friday, with rainfall favoring windward and mauka areas. Expect clearer skies and drier conditions over the holiday weekend, with winds trending lighter Sunday and Monday.

Discussion

High pressure far north of the islands will drive breezy trade winds into the weekend. Wind speeds will diminish and become fairly light Sunday and Monday as this high moves eastward. A new high building northwest of the area will then bring increasing northeast trade winds early next week. A developing upper low north of Kauai enhanced showers and kept high cloud cover across the state overnight. Rainfall was been especially heavy on Kauai and Oahu, but this activity has decreased this morning. Models show available moisture will decrease over the next 24 hours, easing flooding concerns. However, lingering instability keeps a chance for thunderstorms in the forecast for the Big Island interior this afternoon.
The upper low will move east of the islands Friday night and Saturday, allowing upper ridging to build over the area from the west. Expect a much drier trade wind weather pattern this weekend. The high building northwest of the area early next week may push a weak front across the islands around Tuesday, bringing a brief increase in windward showers. Otherwise, rainfall will be limited, favoring windward areas.

Aviation

The wet and breezy trade wind pattern will persist through the 24-Hr forecast period due to moisture being drawn into the area as an upper trough moves through. MVFR conditions with periods of IFR CIGS/VSBYS in showers will continue, especially for windward and mauka areas.
AIRMET SIERRA remains in effect due to mountain obscuration above 2000 feet for north through east sections of all islands.
AIRMET TANGO remains in effect below 8000 feet over and immediately south through west of mountains due to tempo moderate turbulence. AIRMET TANGO also remains in effect between FL180 and FL320 for tempo moderate turbulence.

Marine

Fresh to strong trades will continue over local waters through Thursday before weakening slightly over the weekend. The Small Craft Advisory is out for all waters through today and likely scaled back to the typical windy zones around Maui County and the Big Island on Friday.
A moderate, medium period northwest swell will fill in slowly today and peak Friday. Early long period forerunners continue to build in on the offshore buoys (NDBC 51101/51001) through the early morning hours in the 17 to 19 second bands. This northwest swell event should peak near or under High Surf Advisory (HSA) criteria before declining Saturday. A moderate to large long- period northwest swell is expected to fill in Sunday, peaking Sunday evening well into the HSA criteria, and slowly drop Monday. Indications from forecast models is a large to extra large long- period northwest swell expected next week Tuesday into Wednesday above High Surf Warning levels.
Surf along south facing shores will see a series of small long period background energy keeping the south shore from going completely flat over the next few days. Surf along east facing shores has continued to decline but its compounded by short period wind waves from ongoing trades.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov