Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 86 near the shore to around 74 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 68 to 73 near the shore to around 59 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Sunday: Mostly sunny. Isolated showers in the afternoon. Highs around 86 near the shore to around 74 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs around 83. East winds 10 to 20 mph. 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 72. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Sunday: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs around 83. East winds 10 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 73 to 80 in the valleys to around 64 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 59 to 64 in the valleys to around 54 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 73 to 80 in the valleys to around 64 above 4000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 76 to 85. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 72. East winds up to 15 mph. Chance of rain 40 percent.

Sunday: Partly sunny with scattered showers. Highs 76 to 85. East winds up to 15 mph. Chance of rain 40 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 76 to 84. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 60 to 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 76 to 84. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

High pressure north of the islands will keep moderate to breezy trade winds in place through the middle of next week, with only minor fluctuations in strength from day to day. Rather dry trade wind weather will prevail through the weekend, with light showers favoring windward and mauka areas. A disturbance aloft will begin to influence the weather Sunday night through late next week, bringing an increase in trade wind showers to the island chain. Some old frontal remnants could bring periods of wet weather as they move through during the early to middle part of next week.

Discussion

Currently at the surface, a 1027 mb high is centered around 1350 miles northeast of Honolulu, and is driving moderate to locally breezy trade winds across the island chain early this morning. Infrared satellite imagery shows scattered high clouds moving overhead across the islands and some low clouds getting carried along with the trades. Partly cloudy conditions prevail in most areas, with a bit more cloud cover in some windward areas. Radar imagery shows scattered showers moving into windward areas, with a few showers spilling into leeward areas at times. Main short term focus revolves around rain chances.
High pressure will remain anchored to the northeast of the island chain through the middle of next week, keeping moderate to breezy trade winds in place with only minor fluctuations in strength from day to day. The trades may ease a bit late next week as the high weakens slightly.
As for the remaining weather details, rather dry and stable trade wind weather will continue through the weekend, with light showers favoring windward and mauka areas, mainly during nights and mornings. Ridging aloft is forecast to break down Sunday night and Monday, with a disturbance aloft then holding over or near the islands Tuesday through Friday. This should bring an increase in trade wind showers to the islands beginning Sunday night, with some old frontal remnants potentially bringing periods of wet weather as they move through during the early to middle part of next week.

Aviation

A high pressure ridge north of the Hawaii region will keep moderate to breezy trade winds in the forecast at least through Sunday. Stable conditions will allow for brief showers mainly over the north and east sections of each island, favoring the overnight to early morning hours.
AIRMET Tango remains in effect for moderate low-level turbulence downwind of terrain of most islands. This AIRMET will likely remain in effect for the next several days.

Marine

Moderate to strong easterly trades will continue through most of next week as a surface ridge remains anchored north of the islands. A Small Craft Advisory (SCA) is in effect for the windier waters and channels from Molokai to the Big Island. The SCA will likely be extended through next week, and trade winds may increase slightly late Monday into Wednesday. A downward trend is possible late next week as the ridge settles southward into the area.
An out of season west-northwest swell will maintain surf just above June average along exposed north and west facing shores today. This swell will move out Sunday and Monday with little to no northwest swell energy noted by the middle of next week. In the extended, Typhoon Guchol will likely become extratropical in the northwest Pacific during the middle of next week and may send a larger northwest swell to Hawaii next weekend.
Surf along east facing shores will gradually build through early next week with the fresh trades in place, especially Tuesday through Wednesday as a short-period northeast groundswell mixes in.
Surf along south facing shores will remain small each day as a mix of long-period background south and southwest (170-220 degree) swells move through.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Monday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov