Photo Credit: Brendan Stephen

West Kaua’i

Today: Partly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 70 to 75 near the shore to around 61 above 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

South Kaua’i

Today: Breezy. Mostly cloudy with numerous showers. Highs around 85. East winds 15 to 20 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 68 to 74. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 85. East winds 10 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Breezy. Mostly cloudy with showers. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then showers after midnight. Lows 61 to 66 in the valleys to around 56 above 4000 feet. East winds 10 to 20 mph. Chance of rain 90 percent.

Wednesday: Mostly cloudy. Breezy. Showers in the morning, then scattered showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph decreasing to up to 15 mph in the afternoon. Chance of rain 80 percent.

North Kaua’i

Today: Mostly cloudy with numerous showers. Highs 78 to 87. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 74. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Wednesday: Mostly cloudy with scattered showers. Highs 78 to 87. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy with numerous showers. Highs 78 to 86. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 62 to 76. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Wednesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 78 to 86. East winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will persist through early next week, with clouds and showers favoring windward and mauka areas, particularly during nights and mornings, and a few showers reaching leeward areas from time to time. A bit more showery trade wind pattern is expected today and tonight as the remnant moisture from former tropical cyclone Adrian moves through. The airmass will dry out from east to west across the state Wednesday, with drier than normal trade wind weather then persisting through Friday. The airmass will moisten up again Friday night, bringing a return of more typical trade wind weather which will prevail through early next week.

Discussion

Currently at the surface, a 1026 mb high is centered around 1150 miles northeast of Honolulu, and is driving moderate trade winds in unsheltered areas across the island chain early this morning. Infrared satellite imagery shows mostly cloudy conditions in windward areas, with partly cloudy skies in most leeward locales. Radar imagery shows scattered to numerous showers moving into windward areas, with some of these showers reaching leeward communities at times. Main short term focus revolves around rain chances during the next couple days.
A ridge of high pressure will remain anchored to the north of the islands during the next 7 days, keeping moderate to locally breezy trade winds blowing across the island chain with only minor fluctuations in strength from day to day. Remnant moisture from former tropical cyclone Adrian will bring some showery trade wind weather to the islands today and tonight, with a few more showers reaching leeward areas than normal. The airmass will dry out from east to west across the state Wednesday, with a rather dry trade wind pattern then prevailing through Friday. The airmass is expected to moisten up again Friday night through early next week, bringing a return of more typical trade wind weather to the island chain.

Aviation

Moderate to breezy easterly trade winds will continue through the 24-hr forecast period, with clouds and showers favoring windward and mountain locations. Shower coverage has increased overnight, which will continue today as an area of deeper moisture associated with former Tropical Cyclone Adrian moves through. Some of these showers will manage to make it over leeward areas of the smaller islands. This will translate to periods with MVFR conditions in and around showers moving through.
AIRMET Sierra for mountain obscuration is now in effect for all windward zones as the aforementioned area of deeper moisture begins to move through. This will likely continue through at least the morning hours. Conditions should begin to improve from east to west later today through tonight.
AIRMET Tango for lee turbulence remains in effect.

Marine

A ridge of high pressure north of the islands will keep moderate to locally strong trade winds in place through the weekend. A Small Craft Advisory is now in effect for the typically windy waters around Maui and the Big Island through Thursday, and this will likely need to be extended through the weekend.
Surf along south facing shores will see an increase today along with a second pulse that is slightly larger that will peak on Wednesday. Medium to long period energy has already started showing up at the nearshore buoys south of the islands which will keep surf near or a notch above the summer time average today and Wednesday. However, surf is not expected to reach the advisory level of 10 feet with this event. South shore surf will then decline to mainly background levels Friday through next weekend.
Surf along north facing shores will hold at typical summer levels during the next 7 days. East shore surf will change very little through the weekend, remaining slightly below normal.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov