Photo Credit: Brendan Stephen

West Kaua’i

Today: Mostly sunny with isolated showers. Highs around 83 near the shore to around 72 above 3000 feet. West winds up to 10 mph shifting to the southeast in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows 63 to 70 near the shore to around 53 above 3000 feet. Light winds.

Wednesday: Mostly sunny. Highs around 83 near the shore to around 72 above 3000 feet. Light winds becoming southwest up to 10 mph in the afternoon.

South Kaua’i

Today: Sunny. Highs around 80. Light winds.

Tonight: Partly cloudy. Lows 60 to 69. North winds up to 10 mph.

Wednesday: Mostly sunny. Isolated showers in the late morning and afternoon. Highs around 80. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny with isolated showers. Highs 71 to 77 in the valleys to around 63 above 4000 feet. North winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 52 to 60 in the valleys to around 48 above 4000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Wednesday: Partly sunny with isolated showers. Highs 71 to 77 in the valleys to around 63 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

North Kaua’i

Today: Partly sunny with isolated showers. Highs 73 to 83. Northwest winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 57 to 68. West winds up to 10 mph shifting to the south after midnight. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 73 to 83. Southeast winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

East Kaua’i

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 72 to 82. Northwest winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 53 to 71. North winds up to 10 mph. Chance of rain 20 percent.

Wednesday: Partly sunny with isolated showers. Highs 72 to 82. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Mostly dry and pleasant conditions will prevail through the week as high pressure builds to the north. Light to moderate northerly winds will shift out of a more typical northeast trade wind direction Wednesday through the second half of the week. As the trades return, clouds and light showers will favor the typical windward and mauka locations overnight through the morning hours.

Discussion

The morning satellite imagery showed deep low pressure to the north and its attendant surface front that moved through over the past couple of days shifting east of the state as a trough. The back edge of the low-level cloud band currently over the Big Island will linger this morning with a few spotty showers, then shift east of the area later today. Elsewhere, light to moderate north-northwest winds have filled in over the islands in the wake of the front, ushering in a much drier air mass. Dewpoints have dipped into the upper 50s to low 60s, which have led to pleasant conditions. The latest model guidance has initialized well with the current pattern and depicts mostly dry conditions prevailing through the week as high pressure builds north of the state. The northerly winds will linger into Wednesday (light enough for localized land/sea breezes to form), then shift out of the northeast through the rest of the week. The strong winds at the summits of the Big Island will continue to ease today through midweek as the upper system moves away from the area. Although mostly dry conditions will prevail, a weak upper trough moving in Wednesday through Thursday, combined with a remnant low-level moisture boundary settling south into the area may be enough for a few light showers over north through northeast facing slopes. The breezy trades will weaken briefly late Friday through Saturday as a weak system passes to the north, then return to breezy levels Sunday into early next week as high pressure builds to the north.

Aviation

A weak front near the Big Island will shift slowly southeast today, with light northerly flow filling in across the island chain. The winds will be light enough to allow for daytime sea breezes and overnight land breezes in many areas. Lingering low clouds and showers will keep some MVFR cigs/vsbys affecting the Big Island early this morning, with improving conditions expected later today. Elsewhere, VFR conditions are expected during the next 24 hours.
AIRMET Sierra remains in effect for mountain obscuration across windward sections of the Big Island. Conditions should improve here later this morning.
AIRMET Tango remains in effect for moderate turbulence N through NE of the mountains on the Big Island. This AIRMET will likely be cancelled later this morning.

Marine

Remnants of the old front near the Big Island will dissipate and drift southeast today. Light to moderate northwest to north winds have filled in behind the front except moderate south to southwest winds over the far east Big Island waters. Winds look to veer through the day with light northwest to north winds, before moderate to fresh northeast winds will fill in by late Wednesday through Friday.
Surf along north and west facing shores has filled in overnight as a mixed- period northwest swell continues to build at nearshore PacIOOS Waimea Buoy, bringing elevated surf to exposed shores. A Small Craft Advisory for Kauai waters for seas is in effect through 6 pm HST today. This swell will hold through the day then gradually diminish as it becomes increasingly north Wednesday. Otherwise, a combination of southeast and southwest swells will support small to moderate surf along south facing shores the next couple of days. Surf along east facing shores will remain very small, then gradually trend up as the northeast trade winds increase later in the week.

HFO Watches/Warnings/Advisories

High Wind Warning until 10 AM HST this morning for Big Island Summits.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters.

Data Courtesy of NOAA.gov