West Kaua’i

Today: Sunny with isolated showers. Highs 86 to 93 near the shore to around 78 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly clear with isolated showers. Lows 70 to 75 near the shore to around 62 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Friday: Sunny with isolated showers. Highs 86 to 93 near the shore to around 78 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny. Isolated showers in the morning. Highs 84 to 91. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 74. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 84 to 91. East winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 86 in the valleys to around 68 above 4000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 70 in the valleys to around 59 above 4000 feet. East winds up to 10 mph increasing to 10 to 15 mph after midnight. Chance of rain 40 percent.

Friday: Partly sunny with scattered showers. Highs 77 to 85 in the valleys to around 68 above 4000 feet. East winds 10 to 15 mph decreasing to up to 10 mph in the afternoon. Chance of rain 40 percent.

North Kaua’i

Today: Mostly sunny with isolated showers. Highs 79 to 89. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 66 to 74. East winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 79 to 89. East winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Mostly sunny with isolated showers. Highs 76 to 89. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 78. East winds around 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 77 to 89. East winds around 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Partly cloudy, warm and breezy trades the next few days as the state remains under a stable weather pattern. Limited showers will be primarily confined to windward upslope mauka and within higher terrain. Precipitation will potentially increase over the eastern end of the state this weekend in advance of Tropical Cyclone Kiko. Kiko is forecast to reach our far eastern offshore waters early next week. While a large amount of uncertainly exists, there exists the threat for high rainfall that could lead to flooding in association with Kiko.

Discussion

The islands remain under the stable influence of an upper ridge axis extending from mid to upper ridging centered about 1,200 miles northeast of Big Island. Water vapor satellite imagery is depicting the bulk of the drier air in association with the ridge moving around its western periphery. This is supporting the recently warm and dry weather over the eastern half of the state. Cyclonic steering flow in relation to a deepening trough of low pressure northwest of Kauai is impinging on the ridge and neither feature is giving up much ground in this quasi-static synoptic pattern. Overall, the eastern ridge will win out and any higher southwesterly moisture being pulled up along the trough will stay north and west of the state the next few days. Thus, stability will rule and this wash-rinse-repeat weather behavior will be around into the weekend. A benign surface high northeast of the state has maintained a unseasonably weak downstream pressure gradient. This has ultimately resulted in light to moderate trades. Warm days will persist with many communities peaking in the middle to upper 80s by 2 PM under ample sunshine within resident dry air. High stability and a lack of upstream moisture will result in any measurable rain focusing along windward exposures and upslope mauka through Saturday.
Tropical Cyclone Kiko is now moving west at around 10 mph and is forecast to move into our eastern offshore waters, or pass 150W, late next Monday. The track of Kiko will be determined by the drier Central Pacific environment it will be moving into the next couple of days as well as its interaction with increasing southwesterly shear brought on by the aforementioned northwest trough. As of this time, due to the high uncertainly of Kiko's intensity and track, the messaging for the state is focused on the potential for greater rainfall leading to a flood threat during the Monday through early Thursday time frame. Please refer to the National Hurricane Center concerning the official forecasts of TC Kiko's track and intensity.

Aviation

Moderate trades are expected the next few days. Brief periods of low clouds and showers will be possible over windward slopes during the overnight hours. Generally, VFR conditions will prevail but with occasional MVFR during periods of moderate showers. A trough draped across American Samoa will keep vicinity showers in place over NSTU through the period with a chance of afternoon vicinity thunderstorms and/or towering cumulus. No AIRMETS are in effect.

Marine

A weak surface ridge to the north will remain nearly stationary through the weekend. This will maintain gentle to locally fresh trade winds with some localized sea breezes, especially across leeward waters. Hurricane Kiko, approximately 1,500 nm southeast of Honolulu, continues to track westward in the Eastern Pacific, and is forecasted to move into the eastern offshore and coastal waters early next week.
Surf along north facing shores will remain tiny to small over the next few days as reinforcing small short to medium period north- northwest swells are expected. In the extended forecast, the northwest Pacific looks to get active as low pressure systems traverse the basin over the weekend sending the potential for a few small to moderate northwest swells during the middle of next week. Surf along south facing shores will see background medium- to long-period energy through the week before a small to moderate long-period south-southwest swell fills in and peaks over the weekend. Below average surf is expected to continue along east facing shores through the rest of the week. In the extended forecast, easterly energy from Tropical Cyclone Kiko is expected early next week. This will bring the potential for surf to reach High Surf Advisory criteria.
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

Afternoon humidities will briefly fall into the upper 30s to middle 40s under these dry, warm conditions. Winds will remain below critical fire weather thresholds as light to moderate trade winds are forecast through the weekend. Limited rainfall will occur the next couple of days. Trade wind showers may likely increase in coverage over windward areas of Big Island and Maui early next week as TC Kiko approaches the state from the east.

HFO Watches/Warnings/Advisories

None.

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