Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 88 near the shore to around 76 above 3000 feet. West winds up to 10 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Scattered showers early in the evening. Scattered showers after midnight. Lows 65 to 70 near the shore to around 56 above 3000 feet. Light winds. Chance of rain 50 percent.

Thursday: Mostly sunny in the morning then becoming mostly cloudy. Scattered showers. Highs around 88 near the shore to around 76 above 3000 feet. Southeast winds up to 10 mph. Chance of rain 50 percent.

South Kaua’i

Today: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85. West winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 63 to 69. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 85. Southeast winds up to 10 mph. Chance of rain 40 percent.

Kaua’i Mountains

Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. Light winds. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 56 to 61 in the valleys to around 51 above 4000 feet. Light winds. Chance of rain 50 percent.

Thursday: Partly sunny. Scattered showers in the morning, then numerous showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. Light winds becoming east up to 10 mph in the afternoon. Chance of rain 60 percent.

North Kaua’i

Today: Mostly sunny. Scattered showers in the afternoon. Highs 78 to 87. West winds up to 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 59 to 69. Light winds. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 78 to 87. East winds up to 10 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 78 to 86. West winds up to 10 mph shifting to the east in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 57 to 71. Light winds. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 78 to 86. Southeast winds up to 10 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A land and sea breeze pattern is expected through Thursday, with sea breezes allowing for the development of a few daytime heating driven showers each afternoon, while land breezes keep most showers offshore or very near the coast each night. Moderate trade winds and a more typical windward and mauka focused shower pattern should return Friday, with this pattern then holding through early next week.

Discussion

Currently at the surface, a cold front is located around 175 miles northwest of Kauai, while a 1031 mb high is now over 2000 miles northeast of Honolulu. Light winds prevail, with land breezes present statewide. Infrared satellite imagery shows mostly clear conditions, with radar imagery showing only a few showers out over the coastal waters. Main short term focus revolves around rain chances and timing the returning trades back into the island chain.
A land and sea breeze pattern is expected to prevail through early Thursday, as an approaching front keeps the gradient weak. The front is forecast to stall out just northwest of Kauai tonight, then weaken into a trough and shift westward through the remainder of the work week while ridging rebuilds to the northwest of the islands. This should allow the trade winds to slowly return from east to west across the state Thursday and Thursday night, with moderate trades then holding in place Friday through early next week.
As for the remaining weather details, sea breezes will drive the development of a few showers over interior and mauka areas this afternoon, with showers holding mainly offshore or very near the coast tonight. The one exception may be Kauai where moisture associated with the front may edge close enough to bring a few more showers onshore tonight. Although the trades will begin to return Thursday, the combination of daytime heating and localized sea breezes will likely allow for some leeward and/or interior shower development in the afternoon once again, with coverage the highest over Kauai where closer to the front. More typical trade wind weather featuring mainly windward and mauka showers should then return Friday and prevail through early next week.

Aviation

Weak land breezes and mostly clear skies this morning will be replaced by light sea breezes and cumulus build-ups this afternoon. Clouds and scattered light showers will become focused over island interiors by early afternoon, then weaken and taper off after sunset. Brief MVFR ceilings or visibilities are likely in showers. Otherwise, VFR conditions will prevail all areas.
No AIRMETS are currently in effect or anticipated at this time.

Marine

A cold front moving through the northwest offshore waters this morning will hang up and linger over these waters north northwest of the islands through early Friday. This scenario has kept the pressure gradient weak across the state and created light east southeast or more variable local coastal water breezes across most of the near and offshore waters. Light winds will continue into Friday until high pressure from the west expands in north of the state. This will re-establish moderate to locally fresh trade winds this weekend.
A moderate size northwest (310 degree), medium period swell will be building in across the island chain today. This latest swell will reinforce Monday's northwest swell and peak surf to well over head high (as high as double head high along better exposed Kauai and Oahu north and northwest coasts) today and Thursday. The swell will become more north (340-350 degree) tonight into Thursday as it peaks out. The north swell will begin to subside Friday and fade out through the weekend. Surf along south-facing shores will generally remain hip to chest high through the week in response to a series of small, medium period south southeast swells mixing into the longer period south southwest background. Very small chop will occur along eastern shores through late week under these light and mainly variable breezes.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov