West Kaua’i

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Lows 69 to 74 near the shore to around 62 above 3000 feet. East winds up to 15 mph.

Friday: Mostly sunny with isolated showers. Highs 84 to 90 near the shore to around 77 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Friday Night: Partly cloudy. Lows 68 to 73 near the shore to around 61 above 3000 feet. East winds up to 10 mph.

South Kaua’i

Tonight: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Friday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows around 72. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 65 to 70 in the valleys to around 59 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Friday: Mostly cloudy with scattered showers. Highs 75 to 83 in the valleys to around 66 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy with scattered showers. Lows around 66 in the valleys to around 58 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 65 to 74. East winds up to 15 mph. Chance of rain 40 percent.

Friday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 87. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Friday Night: Mostly cloudy with isolated showers. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 64 to 77. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 74 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 64 to 76. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

The forecast will trend drier as ridging builds into the region. Occasional pockets of moisture embedded within moderate to locally breezy trades will continue to support mainly windward and mauka showers for the next several days. Trade winds could veer to become more east-southeasterly as speeds decrease a bit by the second half of the weekend. The overall drier pattern will continue well into next week.

Discussion

This afternoon, surface high pressure centered far northeast of the main Hawaiian Islands continues to drive locally breezy easterly trade winds across the state. Ridging in the wake of an exiting weak disturbance aloft is resulting in drier conditions today than those experienced the past couple of days, though a weak upper jet is steering a thin layer of cirrus across the eastern half of the state. Afternoon satellite and radar imagery shows very few showers across the state, and rain gauge networks show that most locations have received very little or no rainfall since this morning. Observed 00z soundings at Hilo and Lihue show strong inversions between roughly 6,500 and 7,500 feet, with ample dry air aloft. Low cloud cover is also confined mostly to the typical windward and mauka sections of the islands. This is in addition to the afternoon sea-breeze induced increase in cloud and shower coverage over the Kona slopes of the Big Island.
Global forecast models remain in good agreement that the surface high far northeast of the state will remain nearly stationary through Saturday as it experiences minor fluctuations in intensity. This will result in moderate to breezy trade winds continuing across the main Hawaiian Islands into the weekend. The overall drier trend will continue as well, though pockets of low- level moisture trapped beneath the inversion will result in occasional windward and mauka showers, particularly during the overnight through early morning hours each day.
During the second half of the weekend and into early next week, the surface high to our far northeast will weaken further and move closer to the continental U.S. as a front makes its way across the North Pacific and a new high develops far north- northwest of the state. As this occurs, trades will likely weaken a bit more and veer to become more east-southeasterly during the first half of next week. Showers are expected to be fairly limited throughout this time, mainly favoring windward and mauka areas during the overnight through early morning hours each day. Guidance remains consistent that the second half of next week could be even drier as a new surface high becomes established to our northeast.

Aviation

Beneath a transparent shield of cirrus and patchy mid-level clouds, VFR prevails as breezy trades persist at the surface. Little in the way of upstream moisture suggests MVFR remains patchy in nature and confined to windward and mauka areas, mainly overnight.
AIRMET Tango remains in effect for low-level lee turb.

Marine

High pressure northeast of the state will drive moderate to fresh trade winds for the next several days, with only a slight variation in wind speed and direction expected. A disturbance passing well north of the area late this weekend into early next week may weaken the local pressure gradient slightly and allow the trades to ease. The lightest wind speeds are expected Sunday through Tuesday and are expected to veer out of the east- southeast.
The current south swell that produced near summer average surf will continue to gradually fade to background levels tomorrow into the weekend. Models show another small, long period south swell arriving Sunday into early next week that should boost south shore surf back up to near average surf.
Surf along east shores will remain rough and choppy for the next several days. Surf may lower a notch as the trade winds ease late this weekend into early next week. Surf along north facing shores will remain tiny through the period.
Peak high tides associated with the lunar cycle will cause minor coastal flooding along shorelines and low lying coastal areas this afternoon into the early evening during the daily peak high tide. The Coastal Flood Statement is in effect through this evening and then will likely be allowed to expire as water levels are expected to drop and remain below criteria as daily peak high tides lower and south swell dissipates.

HFO Watches/Warnings/Advisories

None.

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