Photo Credit: Brendan Stephen

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.

Saturday: 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.

Saturday: Partly sunny with isolated showers. Highs around 83. East winds 10 to 15 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 up 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 decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers. Highs 73 to 80 in the valleys to around 64 above 4000 feet. East winds 10 to 15 mph decreasing to up to 15 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 30 percent.

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

Saturday: 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. 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.

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

Saturday: Partly sunny with scattered showers. 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 late next week, with only minor fluctuations in strength from day to day. Rather dry trade wind weather will prevail today 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. A period of wet weather is possible early next week, mainly in windward areas, as some old frontal remnants move through.

Discussion

Currently at the surface, a 1024 mb high is centered around 900 miles north-northeast of Honolulu, while a weakening front is positioned around 650 miles north-northeast of Hilo. The gradient locally is primarily influenced by the high north of the islands and is producing moderate to locally breezy trade winds early this morning. Infrared satellite imagery shows some thin cirrus moving over the islands as well as some low clouds moving into windward areas with the trades. Overall, mostly clear to partly cloudy conditions prevail across the state, with a few pockets of more extensive cloud cover in some windward locales. Radar imagery shows isolated to scattered windward showers and a few leeward spillovers. Main short term focus revolves around rain chances.
High pressure north of the state will lift northeast and strengthen through the weekend, then remain anchored northeast of the islands through late next week. The trades will hold at moderate to breezy levels through late late next week, with only minor fluctuations in strength from day to day.
As for the remaining weather details, rather dry and stable trade wind weather will continue today 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 the islands Tuesday through Thursday. This should bring an increase in trade wind showers to the islands, with some old frontal remnants potentially bringing a period of wet weather when they move through early next week.

Aviation

A high pressure ridge north of the Hawaii region will keep moderate to locally breezy easterly trade winds in place through the weekend. Stable conditions aloft will allow for brief passing showers mainly over windward and mountain areas. VFR conditions will prevail.
No AIRMETs are currently in effect.

Marine

Fresh to strong easterly trades have returned and will continue through much of next week as the ridge remains anchored north of the area. This has resulted in a Small Craft Advisory that has been issued for the windier waters and channels from Molokai to the Big Island, which will likely hold into next week. Seas will respond and climb into the 6 to 8 foot range over these areas.
Surf along exposed north and west facing shores will remain up into early Saturday before easing as an out of season small west- northwest swell moves through. A return of the typical summertime conditions is expected Sunday through Monday.
Surf along east facing shores will rise and become rough as the trades strengthen locally and upstream across the eastern Pacific. Guidance shows a fetch setting up down the 040-070 direction band far northeast of the state Sunday into next week, which will generate a short-period (8-9 sec) groundswell arriving by midweek.
Surf along south facing shores will continue 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 Sunday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov