Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 80 to 85 near the shore to around 71 above 3000 feet. Light winds becoming south up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 66 to 72 near the shore to around 59 above 3000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 80 to 85 near the shore to around 71 above 3000 feet. Light winds. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 80 to 85. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 69. West winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 79 to 86. Light winds. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly sunny in the morning then becoming partly sunny. Highs 72 to 79 in the valleys to around 64 above 4000 feet. West winds up to 10 mph.

Tonight: Partly cloudy with isolated showers. Lows 60 to 66 in the valleys to around 56 above 4000 feet. Southwest winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 71 to 78 in the valleys to around 63 above 4000 feet. Southwest winds up to 10 mph. Chance of rain 20 percent.

North Kaua’i

Today: Mostly sunny. Isolated showers in the morning. Highs 74 to 82. Southeast winds up to 10 mph shifting to the north in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 61 to 70. South winds up to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 73 to 82. Light winds becoming west up to 10 mph in the afternoon. Chance of rain 30 percent.

East Kaua’i

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

Tonight: Partly cloudy. Lows 61 to 71. West winds up to 15 mph.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs 71 to 82. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light winds will persist into next week with limited rain expected over western slopes. Light to moderate trade winds should begin to return by late next week as the subtropical ridge shifts back north of the islands.

Discussion

Weak ridging remains south of the main Hawaiian Islands, keeping our pressure gradient slack and our winds light southwesterlies this morning. Overnight soundings continue to show a dry and stable airmass, with less than 1.3 inches of PW and positive lifted index values. A strong inversion persists near 4500 feet, capping vertical cloud development. Satellite loop shows broken to overcast stable low clouds moving across western portions of Kauai. However, the rest of the state appears to have scattered low clouds to clear skies. Radar shows isolated light showers within scant cloud cover over coastal waters around the smaller islands.
Models show southwesterly flow will keep dry and stable air across the area through the week. Expect limited shower coverage over western slopes, with further drying and increased stability to follow. Benign weather will prevail into next week as flow remains westerly over the western end of the state. Flow will be light enough to allow development of land/sea breezes and modest interior afternoon cloud build-ups. Weak and rapidly decaying fronts will occasionally approach Kauai, falling apart in an environment hostile to rainfall. By next Wednesday, the subtropical ridge should drift just far enough north of the islands to allow light trade winds to reach the state.

Aviation

Light winds will give way to increasing southwesterly winds today as a front approaches from the northwest, although sea breezes may still develop in the more sheltered areas. VFR conditions are expected to prevail statewide.
No AIRMETS are in effect. Moderate to perhaps severe upper level turbulence in the layer between FL250 and FL350 will spread from northwest to southeast down the island chain later today. AIRMET Tango will likely be required with the 22/1600Z AIRMET package.

Marine

A weak high pressure ridge will settle in over the Hawaii region with two cold fronts passing by north of the state into the weekend. This pressure pattern will produce light to moderate breezes with shifting wind directions each day into early next week. The declining NW swell will maintain a Small Craft Advisory (SCA) for high seas for most Kauai waters into the afternoon hours. The SCA was dropped this for all other Hawaiian waters and channels this morning as swell heights fall below SCA thresholds.
The current declining northwest (320 degrees) swell pushing through the islands continues to produce High Surf Advisory level surf heights today along north and west facing shores of Niihau, Kauai, Oahu, Molokai, along north facing shores of Maui. This swell will likely decline below HSA thresholds by late this afternoon to evening. Meanwhile, a fresh overlapping northwest (310 degrees) swell will slowly build into the Hawaii region today, surf heights from this swell peak at HSA levels from Friday through Saturday. HSA level surf heights should continue through Sunday for north and west facing shores as yet another similar northwest swell arrives this weekend. A downward trend in surf heights along north and west facing shores will develop by early next week as this swell energy slowly declines.
Smaller surf heights remain in the forecast this week for south and east facing shores.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST this evening for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Olomana, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters.

Data Courtesy of NOAA.gov