Photo Credit: Braden Jarvis

West Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs around 83 near the shore to around 73 above 3000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows 65 to 70 near the shore to around 56 above 3000 feet. Light winds. Chance of rain 40 percent.

Sunday: Mostly sunny with isolated showers in the morning, then partly sunny with numerous showers in the afternoon. Highs around 85 near the shore to around 75 above 3000 feet. Southeast winds up to 10 mph shifting to the south around 10 mph in the afternoon. Chance of rain 60 percent.

South Kaua’i

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 82. West winds up to 10 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 71. Light winds. Chance of rain 20 percent.

Sunday: Mostly sunny with isolated showers in the morning, then partly sunny with numerous showers in the afternoon. Highs around 84. Southwest winds up to 10 mph. Chance of rain 60 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 71 to 77 in the valleys to around 66 above 4000 feet. Light winds. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening. Lows around 60 in the valleys to around 52 above 4000 feet. Light winds. Chance of rain 40 percent.

Sunday: Mostly sunny in the morning, then partly sunny with numerous showers in the afternoon. Highs 73 to 79 in the valleys to around 68 above 4000 feet. Light winds becoming southwest up to 15 mph in the afternoon. Chance of rain 60 percent.

North Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 73 to 82. West winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening. Lows 60 to 68. Light winds. Chance of rain 40 percent.

Sunday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 84. Light winds becoming north up to 10 mph in the afternoon. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 73 to 83. Light winds. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows 58 to 71. Light winds. Chance of rain 40 percent.

Sunday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 85. Southwest winds up to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Light winds will allow for daytime sea breezes and overnight land breezes through the weekend, with southerly winds picking up late Sunday over the western end of the state. The southerly winds will pick up to moderate levels Sunday night into Tuesday as a front approaches from the west and eventually fizzles out over the western islands. An increase in rainfall will be possible over the Big Island and Kauai from late Sunday night through Tuesday as a couple bands of moisture move into these island, while drier conditions persist over Oahu and Maui County. A return to a land and sea breeze pattern is expected Wednesday through Friday, with a few showers possible near the coast at night and over the island interiors each afternoon.

Discussion

Currently at the surface, a dissipating trough of low pressure is located around 100 miles north of Honolulu, while a cold front around 600 miles northwest of Kauai continues to track southeastward towards the islands at around 15 mph. Light winds have overspread the island chain, with land breezes present statewide. Infrared satellite imagery shows mostly cloudy conditions over Kauai and portions of the Big Island, with partly cloudy skies in most other areas. Radar imagery shows a few showers over Kauai, the Big island and Maui, with very little if any shower activity elsewhere. Main short term focus revolves around wind trends and rain chances/thunder potential associated with an approaching front.
A cold front approaching from the northwest will keep light winds in place during the next couple days, with sea and land breezes dominant statewide. Winds may begin to pick up out of the south Sunday afternoon over the western islands in advance of the approaching front, with moderate south to southwest winds filling in Sunday night and holding in place through Monday night and possibly Tuesday as the decaying front moved into the western islands and fizzles out. Model guidance shows surface ridging becoming re-established over the state Wednesday through Friday, which should keep winds light with sea and land breezes dominant.
As for the remaining weather details, a few showers will be possible mainly near the island coasts this morning, with scattered daytime heating driven showers expected over the island interiors this afternoon into the early evening hours. Mostly dry conditions are expected once the showers diminish in the evening, although a shower or two can't be ruled out near the island coasts overnight into Sunday morning. A few daytime heating driven showers will be possible over the island interiors again Sunday afternoon, with coverage highest over Kauai as some deeper moisture overspreads the island in advance of the approaching front.
The deepest moisture and greatest instability in association with the approaching front appears to remain north and west of the state Sunday night through early next week. Rain chances appear highest over Kauai during this time, and there remains a slight chance of a thunderstorm here Sunday night and Monday. Some deeper moisture may also try to sneak northward into the Big Island Monday through Tuesday as well, bringing a bit higher shower coverage here along with the potential for an isolated thunderstorm each afternoon. Over Oahu and Maui County drier conditions are expected during this time as these islands will remain in the dry slot between deeper moisture to the east and west.
A sea breeze/land breeze pattern appears to become re-established Wednesday through next Friday, with a few showers possible near the island coasts at night and over the island interiors each afternoon.

Aviation

A weakening trough lingering near Kauai will continue to produce a few showers and low ceilings over the island of Kauai this morning. Light southerly winds will allow local scale afternoon sea breezes to form over all islands for the next couple days. Converging sea breeze winds may produce a few showers over leeward and island interior sections. Overnight land breezes will tend to clear out clouds and showers for most areas. The exception will be over the leeward Big Island where isolated to scattered showers will continue overnight along the leeward coast from the Kona District to Upolu Point. Expect VFR conditions to prevail with brief MVFR conditions in any shower bands.
No AIRMETs in effect.

Marine

A trough north of the islands will continue to weaken and drift northward as another cold front approaches the Hawaii Region from the northwest. Expect light to moderate southerly winds lasting into the first half of next week as the next cold front moves into the western islands from Monday night into Tuesday. A weak ridge will build over the state keeping winds light Wednesday through Friday.
Surf along exposed north facing shores will steadily lower through Sunday as a north swell eases. Another north-northwest swell will build in from Sunday night into Monday, then linger through a good portion of next week. Surf heights along both west and north facing shores are forecast to peak near or slightly below the advisory thresholds early next week.
Surf heights along south facing shores will diminish to background levels today and then rise again early next week as overlapping long period south swell energy moves into the Hawaii Region. The first swell will slowly fill in late Sunday through Tuesday. Expect a second south swell to arrive by Wednesday and last through the second half of next week. Surf heights along east facing shores will remain small through much of next week due to lighter winds forecast across the state.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov