Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 87 near the shore to around 76 above 3000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy. Lows around 72 near the shore to around 61 above 3000 feet. East winds up to 10 mph.

Friday: Partly sunny. Isolated showers in the afternoon. Highs around 87 near the shore to around 76 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs 81 to 88. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 73. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Friday: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 81 to 88. East winds 10 to 15 mph. Chance of rain 40 percent.

Kaua’i Mountains

Today: Scattered showers in the morning, then occasional showers in the afternoon. Highs 74 to 85 in the valleys to around 66 above 4000 feet. East winds 10 to 15 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 70 in the valleys to around 59 above 4000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Friday: Mostly cloudy with scattered showers. Highs 74 to 85 in the valleys to around 66 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 76 to 88. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 40 percent.

Friday: Partly sunny with scattered showers. Highs 77 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 74 to 86. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 76. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 74 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate northeast trades will weaken a bit today and tomorrow as a couple fronts north of the islands disrupt the trade wind flow. A surface trough moving through the islands from the east will bring some clouds and showers, mainly to windward areas. Some strengthening of the trades is expected early next week.

Discussion

There are some changes to the PoP grids for the first couple of days with this mornings package. The PoPs have been lowered a bit for the windward sides of the islands based on the National Blend of Models. This seems to be picking up on a weakening of the trough that will be moving through the islands today from the east.
Clouds associated with the southern end of a weakening surface trough have moved over the Big Island, bringing an uptick in shower activity. Satellite shows the clouds with the trough becoming less organized as the trough weakens. Some clouds and showers are likely to move over the smaller islands today, but as indicated above, the PoPs have been lowered a bit.
The upper level low is off to the west of Kauai this morning, with minimum impacts to the local weather. High clouds are moving over the islands from the south on the east side of the upper level low. An upper level ridge building over the islands will help to stabilize the airmass Friday.
A couple of fronts passing far north of the islands will help to maintain light to moderate trades winds into the weekend. Heading into the new week, high pressure will move in behind the fronts, to the north of the islands, allowing trades to rebound to moderate to locally breezy levels.

Aviation

Moderate trades expected through the rest of the week. SHRA and low cigs could bring brief MVFR conds to windward and mauka areas. VFR should prevail elsewhere.
AIRMET Sierra is in effect for mtn obsc for windward Big Island. Conds expected to improve later this morning.

Marine

A ridge of surface high pressure far northwest of the state will remain nearly stationary through this evening and maintain moderate to locally fresh trades across the local waters. Tonight into early this weekend, a weak cold front will drop southward, weaken the pressure gradient, and allow local winds to ease into the gentle to locally moderate range. Small Craft Advisory conditions may develop early next week as a high rebuilds north of the state and moderate to locally strong trade winds return.
As of early this morning, both Hanalei and Waimea buoys indicated the presence of a 3 to 4 foot, 11 to 12 second, north northwest swell. Thus, expect small surf along exposed north facing shores through the remainder of today. This swell will slowly subside through Friday, then bump up again this weekend as a similar size north northwest swell reinforces. The next significant north northwesterly swell (340 degree) is poised to arrive late Sunday into early next week and may be large enough to produce High Surf Advisory level conditions along north facing shores.
Long period forerunners of the next small south swell will begin to trickle in by mid- day today and reinforce background swell currently in place. This new swell should build further on Friday which will add a slight bump up for surf along south facing shores. Surf along west- facing shores will be influenced by a mixture of both north northwest and south swells. Thus, expect western exposures to remain slightly elevated as well. East- facing shore chop will be lower than normal over the next several days as trade wind flow remains relatively weak locally and upstream.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov