West Kaua’i

Rest Of Tonight: Mostly clear. Lows 70 to 75 near the shore to around 61 above 3000 feet. Light winds.

Saturday: Mostly sunny with isolated showers. Highs 85 to 92 near the shore to around 77 above 3000 feet. East winds up to 10 mph shifting to the south in the afternoon. Chance of rain 20 percent.

Saturday Night: Mostly clear. Isolated showers after midnight. Lows around 73 near the shore to around 61 above 3000 feet. Light winds. Chance of rain 20 percent.

South Kaua’i

Rest Of Tonight: Partly cloudy with isolated showers. Lows 71 to 76. Northeast winds around 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Isolated showers in the morning. Highs 83 to 91. East winds around 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy with isolated showers. Lows around 73. Northeast winds around 10 mph in the evening becoming light. Chance of rain 20 percent.

Kaua’i Mountains

Rest Of Tonight: Partly cloudy. Isolated showers late in the evening, then scattered showers after midnight. Lows 63 to 70 in the valleys to around 59 above 4000 feet. East winds up to 10 mph. Chance of rain 40 percent.

Saturday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 85 in the valleys to around 68 above 4000 feet. East winds up to 10 mph. Chance of rain 30 percent.

Saturday Night: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 63 to 70 in the valleys to around 59 above 4000 feet. Light winds. Chance of rain 40 percent.

North Kaua’i

Rest Of Tonight: Partly cloudy with isolated showers. Lows 65 to 73. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers. Highs 78 to 88. East winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy with isolated showers. Lows 65 to 73. East winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

East Kaua’i

Rest Of Tonight: Partly cloudy with isolated showers. Lows 65 to 78. Northeast winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers. Highs 76 to 88. East winds up to 10 mph. Chance of rain 20 percent.

Saturday Night: Partly cloudy with isolated showers. Lows 65 to 77. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light to moderate trade winds will persist into early next week, occasionally disrupted by land and sea breezes. Generally dry and stable conditions will prevail, though shower activity may increase slightly late Sunday into Monday as an upper level low approaches. Attention then turns to Hurricane Kiko, which may influence island weather next week depending on its eventual track.

Discussion

Light to moderate trade winds will continue through the weekend as weak high pressure to the north remains disrupted by a surface low/trough. This weaker background flow will allow localized sea breezes to develop each afternoon, producing clouds and a few light showers over leeward and interior areas. Subsidence from mid-level ridging and the intrusion of drier air will help limit rainfall coverage and intensity through Saturday night.
From Sunday into Monday morning, a band of moisture embedded within the lighter trades combined with increasing mid- to upper- level instability from an approaching upper level low may lead to a modest uptick in shower activity.
Attention then shifts to Tropical Cyclone Kiko. Kiko is currently a Category 4 hurricane moving west-northwest at 10 mph. The latest forecast track from the National Hurricane Center has shifted slightly to the right of the previous forecast track and has it weakening to tropical storm strength by Tuesday as it passes north and east of the island chain. For now, the main impacts look to be focused on the marine-side of things as detailed in the marine section below. However, we will continue to monitor Kiko's track for the potential to see any direct impacts from winds and rainfall.

Aviation

Light to moderate trade winds will prevail across the state. Trades will weaken this weekend as a trough moves closer to the Hawaiian Islands, remaining NW of the state, while Tropical Cyclone Kiko approaches the area from the southeast. Brief periods of MVFR conditions associated with occasional showers are possible, primarily over windward an mountainous areas. Otherwise, VFR conditions are expected.
There are currently no AIRMETs in effect, and none are anticipated through tonight.

Marine

Weak surface ridging just north of the state will continue to produce moderate trades through tonight. A weak trough is expected to develop just north of the islands this weekend and cause trade winds to ease into the gentle to moderate range with localized sea breezes. Moderate to locally fresh trade winds should briefly return on Monday.
Hurricane Kiko, approximately 1000 NM ESE of Hilo, continues to track west northwest in the Eastern Pacific. The latest forecast from the National Hurricane Center has Kiko entering our offshore waters late Monday as a strong Tropical Storm or weak Hurricane. Kiko is then expected to skirt our coastal waters, north of the Big Island or Maui County, as a tropical storm on Tuesday. Please keep a close eye on the future National Hurricane Center forecast track updates as the system approaches.
A small, short period, northwest swell will bring small surf to north facing shores through this weekend. In the extended forecast, additional small northwest swells from distant north pacific disturbances will continue to generate rounds of small surf along north facing shores through mid-next week.
A moderate long-period south-southwest swell will gradually fill in on Saturday and peak on Sunday above the summer average. As this swell declines on Monday, another reinforcing swell out of the south-southwest is expected on Tuesday. This should help maintain surf near or slightly above the summer average throughout the first half of next week.
Surf along east facing shores will steadily rise Sunday through early next week as swell energy from Tropical Cyclone Kiko arrives. The surf may approach High Surf Advisory Criteria as early as Monday and possibly breach High Surf Warning levels Monday night into Tuesday. However, surf heights will be highly depended on the track and intensity of Kiko as it nears the state.
Peak monthly high tides, combined with water levels running higher than predicted, may lead to minor flooding along the shoreline and in low-lying coastal areas. A Coastal Flood Statement remains in effect through Sunday afternoon.

Fire weather

While afternoon humidities will briefly fall into the upper 30s to middle 40s under dry and warm conditions, winds will remain below critical fire weather thresholds with light to moderate winds forecast through Sunday. On Monday, drier air will filter across the state, dropping relative humidities, but winds should still remain below critical fire weather thresholds. Showers may increase in coverage and intensity over many windward exposures early to mid next week as TC Kiko passes north of the state.

HFO Watches/Warnings/Advisories

None.

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