Photo Credit: Sebastien Gabriel

West Kaua’i

Rest Of Today: Partly sunny. Breezy. Isolated showers in the morning. Highs around 79 near the shore to around 64 above 3000 feet. North winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 60 near the shore to around 50 above 3000 feet. North winds up to 20 mph shifting to the northeast 10 to 15 mph after midnight. Chance of rain 20 percent.

Friday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 77 near the shore to around 62 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

South Kaua’i

Rest Of Today: Partly sunny. Isolated showers in the morning. Highs 75 to 80. Light winds becoming east up to 15 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 59. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Friday: Breezy. Mostly sunny with isolated showers. Highs 73 to 78. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Rest Of Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 68 to 74 in the valleys to around 58 above 4000 feet. North winds up to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Breezy. Scattered showers in the evening, then isolated showers after midnight. Lows 51 to 57 in the valleys to around 47 above 4000 feet. North winds up to 15 mph increasing to up to 25 mph after midnight. Chance of rain 30 percent.

Friday: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 66 to 72 in the valleys to around 56 above 4000 feet. Northeast winds 10 to 25 mph. Chance of rain 40 percent.

North Kaua’i

Rest Of Today: Breezy. Partly sunny with isolated showers. Highs 68 to 78. North winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 53 to 61. North winds up to 20 mph. Chance of rain 20 percent.

Friday: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 65 to 76. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

East Kaua’i

Rest Of Today: Partly sunny. Isolated showers in the morning. Highs 68 to 79. North winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 52 to 64. North winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Breezy. Mostly sunny with isolated showers. Highs 66 to 76. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Update

The forecast has been updated to better align the PoP and associated parameters in line with the latest radar data. Radar data shows the leading edge of rain associated with the cold front moving down the island chain is over Molokai early this morning, and is expected to spread to Kahoolawe and Maui shortly.

Synopsis

A front will continue moving down the island chain through Friday, bringing a period of clouds and showers to each island in turn. After the front passes, breezy north to northeast winds will deliver a cool air mass through the weekend, with limited windward showers. Gradual warming is expected early next week as trade winds diminish.

Aviation

Moderate southwesterly winds will continue across the eastern half of the state this morning ahead of a cold front currently moving through Oahu. Prefrontal clouds and showers will develop ahead of the main frontal cloud band. Expect brief periods of MVFR ceilings and visibilities with showers as the cold front passes through each island.
This cold front will reach the islands in Maui County later this morning, and then spread to the Big Island by this afternoon. Expect improving weather trends after the front passes each island with breezy northerly winds as high pressure builds in quickly behind the frontal trough.
AIRMET Sierra remains in effect for mountain obscurations above 2,000 feet over Kauai and Oahu this morning. This AIRMET will likely spread eastward to islands in Maui County later this morning.
AIRMET Tango remains in effect for moderate turbulence over and down wind if island mountains on Kauai and Oahu this morning. This AIRMET will likely spread eastward to the islands in Maui County later this morning.

Marine

A front will push southeastward down the island chain through the day. Gentle to moderate southwesterlies ahead of the front will transition to moderate to locally fresh northerlies in the wake of the front. As backing surface high pressure builds in behind the front and tightens the northwest pressure gradient against the state, weekend northeasterlies will subtly strengthen into the fresh to locally strong range. Early week winds will shift to a more easterly direction while holding at moderate to locally strong levels as the high north of the state moves off to the east.
Surf will sharply increase to XL size along many northern and western exposures progressive down the island chain through the day as a very large northwest swell (320 degree) builds in from the northwest. The swell will peak later Thursday and then gradually lower into Friday. A High Surf Warning (HSW) is in effect for the north and west-facing shores of Niihau, Kauai, Oahu, Molokai, Big Island and north facing shores of Maui through Friday afternoon. A Small Craft Advisory is also in effect for all waters (sans Maalea Bay) as a result of high seas created by this swell. This large swell will adversely impact coastal areas, especially during high tide times Thursday and Friday. Preparations should be made for significant coastal impacts as ocean water runs up and inundates beaches and potentially adversely affects coastal properties and roadways.
As the northwest swell fades, a moderate to large size, medium period north swell (350-010 degree) will build on its heels Friday night and Saturday, likely peaking surf at high end High Surf Advisory (HSA) or low end HSW heights along better exposed north-facing shores Saturday night and Sunday. North wrap may push weekend eastern shore surf up to HSA thresholds with the potential for this wrap to also make it into the west-facing shores of Maui and Big Island. The north swell will gradually lower as it shifts more north to northeasterly Monday night through the middle of next week. A new small to moderate size northwest swell may move through from late Monday into the middle of next week. South shore surf will remain small over the next several days.

Prev discussion

/ISSUED 331 AM HST Thu Feb 15 2024/
Breezy southwest winds prevail across local waters from Oahu eastward this morning, thanks to a front passing across Oahu and a weakened ridge which has been pushed south of the Big Island. Post-frontal northerly flow is building in across Kauai. Earlier clouds and showers ahead of the front have dissipated, leaving the frontal band across the western islands as the main cloud feature. This 150-mile wide band of broken to overcast showery low clouds marking the front is poised to pass east of Oahu by sunrise. Models show the front reaching Maui County later this morning and the Big Island tonight before moving southeast of the islands by Saturday. Winds across the highest Big Island summits have been steadily increasing overnight, with gusts near 60 mph observed at 3am HST. A High Wind Warning for the Big Island summits remains in effect through Friday afternoon.
As the front passes through the state our airmass will remain mostly stable, with moisture confined to low cloud level. Significant rainfall is therefore not expected. However, the Big Island's Hamakua coast may see several inches of rainfall tonight through Saturday morning, thanks to residual frontal moisture possibly pushed upslope by post-frontal north to northeast winds.
A high northwest of the islands will drive locally breezy north to northeast winds after the front passes, delivering a cool and dry air mass. Clouds and limited light showers will favor north and east coasts and slopes through the weekend as this air mass is slow to warm. The high will pass north of the islands early next week and weaken to the northeast of the islands by midweek, causing trade winds gradually ease while delivering limited windward showers.
AVIATION… Moderate southwesterly winds will continue across the eastern half of the state this morning ahead of a cold front currently moving through Oahu. Prefrontal clouds and showers will develop ahead of the main frontal cloud band. Expect brief periods of MVFR ceilings and visibilities with showers as the cold front passes through each island.
This cold front will reach the islands in Maui County later this morning, and then spread to the Big Island by this afternoon. Expect improving weather trends after the front passes each island with breezy northerly winds as high pressure builds in quickly behind the frontal trough.
AIRMET Sierra remains in effect for mountain obscurations above 2,000 feet over Kauai and Oahu this morning. This AIRMET will likely spread eastward to islands in Maui County later this morning.
AIRMET Tango remains in effect for moderate turbulence over and down wind if island mountains on Kauai and Oahu this morning. This AIRMET will likely spread eastward to the islands in Maui County later this morning.
MARINE… A front will push southeastward down the island chain through the day. Gentle to moderate southwesterlies ahead of the front will transition to moderate to locally fresh northerlies in the wake of the front. As backing surface high pressure builds in behind the front and tightens the northwest pressure gradient against the state, weekend northeasterlies will subtly strengthen into the fresh to locally strong range. Early week winds will shift to a more easterly direction while holding at moderate to locally strong levels as the high north of the state moves off to the east.
Surf will sharply increase to XL size along many northern and western exposures progressive down the island chain through the day as a very large northwest swell (320 degree) builds in from the northwest. The swell will peak later Thursday and then gradually lower into Friday. A High Surf Warning (HSW) is in effect for the north and west-facing shores of Niihau, Kauai, Oahu, Molokai, Big Island and north facing shores of Maui through Friday afternoon. A Small Craft Advisory is also in effect for all waters (sans Maalea Bay) as a result of high seas created by this swell. This large swell will adversely impact coastal areas, especially during high tide times Thursday and Friday. Preparations should be made for significant coastal impacts as ocean water runs up and inundates beaches and potentially adversely affects coastal properties and roadways.
As the northwest swell fades, a moderate to large size, medium period north swell (350-010 degree) will build on its heels Friday night and Saturday, likely peaking surf at high end High Surf Advisory (HSA) or low end HSW heights along better exposed north-facing shores Saturday night and Sunday. North wrap may push weekend eastern shore surf up to HSA thresholds with the potential for this wrap to also make it into the west-facing shores of Maui and Big Island. The north swell will gradually lower as it shifts more north to northeasterly Monday night through the middle of next week. A new small to moderate size northwest swell may move through from late Monday into the middle of next week. South shore surf will remain small over the next several days.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 PM HST Friday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala, Big Island East, Big Island North.
High Wind Warning until 6 PM HST Friday for Big Island Summits.
Small Craft Advisory until 6 AM HST Saturday for all Hawaiian waters except Maalaea Bay,

Data Courtesy of NOAA.gov