Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly cloudy with isolated showers. Highs around 78 near the shore to around 66 above 3000 feet. West winds around 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows around 58 near the shore to around 47 above 3000 feet. Northwest winds around 10 mph in the evening becoming light. Chance of rain 30 percent.

Saturday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 78 near the shore to around 66 above 3000 feet. West winds up to 10 mph. Chance of rain 30 percent.

South Kaua’i

Today: Mostly cloudy with isolated showers. Highs around 77. West winds around 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 54 to 59. Northwest winds around 10 mph. Chance of rain 20 percent.

Saturday: Sunny. Isolated showers in the morning. Highs around 77. West winds around 10 mph shifting to the southwest in the afternoon. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly cloudy with isolated showers. Highs 66 to 73 in the valleys to around 60 above 4000 feet. West winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 47 to 52 in the valleys to around 41 above 4000 feet. Northwest winds up to 10 mph. Chance of rain 30 percent.

Saturday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 65 to 73 in the valleys to around 60 above 4000 feet. Southwest winds up to 10 mph. Chance of rain 30 percent.

North Kaua’i

Today: Mostly cloudy with isolated showers. Highs 70 to 77. West winds around 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 50 to 59. Northwest winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Saturday: Mostly sunny. Isolated showers in the morning. Highs 70 to 77. West winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Mostly cloudy with isolated showers. Highs 68 to 78. West winds around 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 48 to 60. Light winds. Chance of rain 20 percent.

Saturday: Mostly sunny. Isolated showers in the morning. Highs 70 to 77. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Drier than normal conditions will persist through the weekend as a ridge of high pressure develops over the area. Expect a few interior showers each afternoon, but total rainfall will be light. South to southwest winds will return late Sunday into early next week, which could increase shower activity.

Discussion

Light westerlies persist across the islands this morning, with a large low to our north affecting flow across a broad stretch of the central North Pacific. Satellite loop shows a ragged band of broken to overcast middle and high clouds across the state, marking the southern edge of the jetstream along the south flank of the low. Scattered low clouds are noted within breaks in the middle and high clouds, with radar showing minimal shower activity. Overnight soundings show a dry and stable airmass remains in place, with the Lihue sounding showing less than an inch of PW, positive lifted index values, and a strong capping inversion.
Expect light westerly flow today at lower elevations. Winds may be light enough for sea breezes to develop, but interior showers will be sparse given our dry airmass. However, windward slopes of the Big Island may see afternoon clouds and a few light showers. Winds on the summits of the Big Island will remain above warning threshold through the weekend, with localized wind gusts of over 90 mph.
High pressure will build across the region over the weekend. Expect a continuation of the current weather pattern, with light winds and fair weather conditions. A few light showers may occur over interior areas, but for the most part we will likely see only afternoon clouds with an isolated light shower or two. Another low passing north of the state on Sunday will likely introduce southerly wind flow. Expect increased showers within this flow by early next week. Another front may reach the islands from the northwest late next week.

Aviation

Weak high pressure will persist statewide. Light sea breezes will drive weather in the afternoon and early evening hours. Weak land breezes will predominate in the late night and early morning hours. Layered mid and high level clouds streaming in from the west are the result of a nearby upper level jet.
Late night radar imagery reveals a band of persistent light showers along the Windward coast of the big island south of Laupahoehoe. Elsewhere across the state, only isolated showers can be detected. Shower coverage is expected to remain minimal today, but become focused over island interiors in the afternoon and evening hours.
AIRMET Tango for mid level turbulence to the lee side of Big Island higher terrain remains in effect due to brisk west winds at and near summit level. Conditions are expected to end later this morning.

Marine

A surface ridge over the islands with weak lows passing just north of the state will produce light westerly winds today, then light and variable winds on Saturday and Sunday, becoming moderate southwesterly winds from Sunday night through Wednesday. The Small Craft Advisory (SCA) was also extended through this afternoon for most coastal waters due to lingering high seas. This SCA should drop for all coastal waters by tonight as the northwest swell heights decrease.
The large northwest (320) swell will decrease today and continue to produce warning level surf along north and west facing shores on the smaller islands and west facing shores of the Big Island through this afternoon. The High Surf Warning was extended through this afternoon. This swell will then subside below warning levels later tonight, where a High Surf Advisory will be issued this evening as the northwest swell decreases. A medium period smaller north (360-020) swell is expected to move in by Saturday and will bring elevated surf to north facing shores into early next week.
Minimal trade wind swell is expected this week, though there is some potential for wave wrap along east facing shores exposed to the next north swell due to arrive this weekend. South facing shores will remain small this week with only background swell energy.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 PM HST this evening 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.
High Wind Warning until 6 PM HST Sunday for Big Island Summits.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters, Alenuihaha Channel, Big Island Windward Waters.

Data Courtesy of NOAA.gov