Photo Credit: Jason Weingardt

West Kaua’i

Today: Breezy. Partly sunny with isolated showers. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers. Lows 70 to 75 near the shore to around 61 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Sunday: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs around 85. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 68 to 74. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 85. Northeast winds 15 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Mostly cloudy. Breezy. Occasional 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. Chance of rain 80 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous 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 70 percent.

Sunday: Partly sunny. Breezy. Numerous 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. Chance of rain 70 percent.

North Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 87. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

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

Sunday: Partly sunny with scattered showers. Highs 78 to 87. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

East Kaua’i

Today: Breezy. Mostly cloudy with scattered showers. Highs 78 to 86. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 75. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Partly sunny with scattered showers. Highs 78 to 86. Northeast 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 blowing through Monday, strongest over the weekend. Showers will favor windward and mauka areas mainly during nights and mornings with some of these showers reaching leeward communities at times. The remnants of former tropical cyclone Adrian should ease the trades and increase shower coverage and intensity Monday night into Wednesday. Moderate to locally breezy trades and drier trade wind weather should return late Wednesday through the end of the work week.

Discussion

Currently at the surface, a 1026 mb high is centered around 1000 miles north-northeast of Honolulu, and is driving moderate to breezy trade winds across the island chain early this morning. Infrared satellite imagery shows mostly cloudy conditions across much of the state. Radar imagery shows numerous showers moving into windward areas, with quite a few showers spilling over into leeward communities as well. Main short term focus revolves around trade wind trends and rain chances during the next several days.
High pressure north of the islands will keep moderate to breezy trade winds blowing through Sunday. The ridge north of the islands will weaken Sunday night through early next week as the remnants of former tropical cyclone Adrian approach and move through the area from east to west. This should ease trades back to moderate levels across the islands. Once the remnants of Adrian shift west of the state, we should see a return to moderate to locally breezy trades for Thursday and Friday.
As for the remaining weather details, fairly typical trade wind weather will prevail through Monday. Showers will favor windward and mauka areas, with some of these showers spilling over into leeward communities at times. We should see an increase in trade wind shower coverage and intensity as the remnant moisture from former tropical cyclone Adrian moves through from east to west across the state Monday night into Wednesday, with more of these showers reaching leeward communities as well. Things appear to dry out pretty noticeably following the passage of the remnants of Adrian, with drier than normal trade wind weather expected late Wednesday through the end of the work week.

Aviation

A high pressure ridge far north of the Hawaiian Islands will continue to produce moderate to breezy trade winds this weekend. Expect passing showers, mainly along north and east slopes of each island favoring the overnight to early morning hours. Leeward areas will see mostly isolated shower coverage as stronger showers drift over south and west slopes of each island.
AIRMET Sierra remains in effect for mountain obscuration over windward mountains of Kauai Oahu Molokai Maui and the Big Island. This AIRMET will likely remain in effect through the early morning hours.
AIRMET Tango remains in effect for moderate turbulence over and south through west of mountains. This AIRMET will continue through the weekend.

Marine

Fresh to strong easterly trade winds will continue through the weekend, then potentially ease slightly Monday through Wednesday. The Small Craft Advisory currently in place for the windier waters and channels has been extended through Sunday.
Surf along south facing shores will remain around the summertime average through the weekend, with mainly a combo of small southwest and southeast swell energy moving through. An upward trend is expected early next week as a fresh south-southwest swell arrives. This swell will peak Tuesday through Wednesday, then ease into the second half of the week.
Surf along north and west facing shores will peak today as a small north-northwest swell moves through. The offshore/nearshore buoy observations reflect this source this morning, which line up well with guidance. Surf will lower back to the summertime average by Monday.
Surf along east facing shores will remain small and choppy into early next week with the trades in place. A downward trend is possible by midweek as the trades ease.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Sunday for Kauai Northwest Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov