Photo Credit: Braden Jarvis

West Kaua’i

Today: Sunny. Highs around 81 near the shore to around 68 above 3000 feet. Northwest winds around 10 mph.

Tonight: Mostly clear. Lows around 66 near the shore to around 55 above 3000 feet. Light winds.

Friday: Sunny. Highs around 82 near the shore to around 68 above 3000 feet. Southwest winds up to 10 mph.

South Kaua’i

Today: Sunny. Highs around 81. West winds around 10 mph shifting to the southwest in the afternoon.

Tonight: Mostly clear. Lows around 64. Northwest winds around 10 mph.

Friday: Sunny. Highs 78 to 83. Southwest winds around 10 mph.

Kaua’i Mountains

Today: Sunny. Isolated showers in the afternoon. Highs 72 to 78 in the valleys to around 63 above 4000 feet. West winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 56 to 63 in the valleys to around 54 above 4000 feet. West winds up to 15 mph.

Friday: Sunny. Highs 73 to 79 in the valleys to around 63 above 4000 feet. Southwest winds 10 to 15 mph.

North Kaua’i

Today: Sunny. Highs 71 to 80. Northwest winds around 10 mph.

Tonight: Mostly clear. Lows 59 to 66. Southwest winds up to 10 mph.

Friday: Sunny. Highs 71 to 81. Southwest winds up to 10 mph.

East Kaua’i

Today: Sunny. Highs 73 to 82. Light winds.

Tonight: Mostly clear. Lows 58 to 68. Light winds.

Friday: Sunny. Highs 73 to 82. Southwest winds up to 10 mph.

Detailed Forecast

Synopsis

Clouds and showers associated with a front will push through Oahu this morning, spreading to Maui County today, bringing a period of gusty showers, some briefly heavy. Winds will ease today to light southwest to west winds as the front stalls, weakens and then dissipates near Maui County. Expect a general drying trend behind the front and as the lingering moisture from the front diminishes today through the weekend. Southwest winds will strengthen Saturday into Monday as another front approaches the state. This next front may bring a modest increase in showers from late Monday through Wednesday, potentially followed by a period of trade winds.

Discussion

Clouds and showers associated with a front will push through Oahu, and spread to Maui County today, some showers will be gusty and heavy at times. Limited clouds and showers will follow behind and ahead of moisture band associated with the front. CIMSS satellite imagery shows about one inch or less of precipitable water following the front and near the Big Island. Breezy southwest winds have trended down overnight and will become light out of the west today. Meanwhile, wind speeds over the Big Island Summits have increased overnight to warning levels based on latest observations, and are expected to persist through today, thus a High Wind Warning remains in effect through this afternoon.
After the moisture band associated with the front dissipates today a dry weather pattern will set up by Friday into the weekend. A strong mid level ridge will build over the state with dramatically warm 500 mb temperatures, producing shallow clouds with minimal (if any) rainfall. A land sea breeze pattern will set up today and Friday, where areas outside the band of moisture will see clear skies overnight and early morning with clouds and showers developing over interior areas during the afternoon and evening hours. Winds will strengthen back to breezy levels out of the southwest Saturday into Monday as another front approaches the state from the north. The increased southerly flow may bring an isolated leeward shower or two. The front is expected to slide across the state Monday through Wednesday, producing a modest increase in showers. Breezy north winds may develop behind the front as a high pressure system builds to the northwest and progresses eastward.

Aviation

A cold front will continue to progress southeastward across the central islands this morning and then begin to slow and dissipate across Maui County later today. MVFR ceilings and visibility are expected along and behind the front due to clouds and showers. Light to moderate winds can be expected to persist across the state today, with locally breezy winds across Maui County early this morning. Then conditions will begin to clear from west to east later today as drier air filters in and winds will become light and variable overnight.
AIRMET TANGO is in effect along north through east sections of Kauai, Oahu, Molokai, and Maui, in the lee of the mountains, for tempo moderate turbulence. These conditions should gradually improve today.
AIRMET SIERRA is in effect above 2500 feet for Oahu, Molokai, Lanai and Maui for tempo mountain obscuration from clouds and showers as the front moves through. This AIRMET will likely be cancelled from west to east today as drier air filters in behind the front and clears out the clouds and showers.

Marine

Trade winds remain seasonably absent from the 5-day marine forecast, although there is a chance they make an appearance in about a week. Until then, the subtropical ridge will remain S of the islands, and the prevailing flow will be from the SW after a brief period of light to moderate W winds today.
A storm low far to north will shift further north today and the assoicated front will stall and dissipating near Maui. The upper level support that brought isolated thunderstorms to the offshore waters has moved east of the area thus the threat of thunderstorms has diminished. As the front weakens today, light to moderate W winds will develop and persist through Friday. Another front slowly approaching from the NW will nudge the ridge S again Friday and Saturday, with moderate to fresh S to SW winds gradually increasing from W to E across the island chain into early next week. The front may move over the islands Monday night and Tuesday, potentially followed by a period of trade winds.
A fresh pulse of medium-period WNW swell will support an increase in surf heights along exposed N and W facing shores today. A High Surf Advisory (HSA) remains in effect until Friday morning, with the swell expected to gradually diminish Friday and Saturday. Associated seas greater than 10 feet will also persist through today, thus the Small Craft Advisory has been extended for select marine zones until Friday morning.
Another WNW swell will arrive Sunday and Monday, likely leading to HSA-level surf along many N and W facing shores, including leeward Big Island. As a large complex gyre of low pressure fills a large chunk of the N Pacific this weekend, this swell may continue to build Tuesday, pushing surf heights to High Surf Warning levels along exposed shores. This swell is expected to diminish Wednesday and Thursday of next week.
Short-period choppy wind waves along S and W facing shores will ease as winds diminish the next couple of days, but will likely redevelop over the weekend as SW winds increase again. East facing shores have become the “leeward” side, with minimal surf and lack of wind waves.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Friday for north and west facing shores of Niihau Kauai Oahu Molokai, north facing shores of Maui, and west facing shores of Lanai and the Big Island.
High Wind Warning until 6 PM HST this evening for Big Island Summits.
Small Craft Advisory until 6 AM HST Friday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters.

Data Courtesy of NOAA.gov