Photo Credit: Braden Jarvis

West Kaua’i

Today: Sunny. Highs around 89 near the shore to around 78 above 3000 feet. East winds up to 15 mph.

Tonight: Partly cloudy. Lows around 72 near the shore to around 61 above 3000 feet. East winds up to 10 mph.

Monday: Mostly sunny. A 20 percent chance of showers in the afternoon. Highs 86 to 91 near the shore to around 77 above 3000 feet. East winds up to 10 mph shifting to the southwest around 10 mph in the afternoon.

South Kaua’i

Today: Mostly sunny. Breezy. A 40 percent chance of showers in the morning. Highs 82 to 90. Northeast winds 10 to 20 mph.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows around 73. Northeast winds around 10 mph.

Monday: Mostly sunny with a 20 percent chance of showers. Highs 82 to 90. East winds around 10 mph shifting to the southeast in the afternoon.

Kaua’i Mountains

Today: Breezy. Mostly cloudy with showers likely in the morning, then mostly sunny with chance of showers in the afternoon. Highs 75 to 86 in the valleys to around 67 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. A 50 percent chance of showers. Lows 63 to 70 in the valleys to around 59 above 4000 feet. East winds 10 to 15 mph.

Monday: Partly sunny with a 50 percent chance of showers. Highs 76 to 85 in the valleys to around 68 above 4000 feet. East winds around 10 mph.

North Kaua’i

Today: Partly sunny with chance of showers in the morning, then mostly sunny with slight chance of showers in the afternoon. Highs 78 to 89. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows 65 to 73. East winds up to 10 mph.

Monday: Mostly sunny with a 20 percent chance of showers. Highs 78 to 89. East winds up to 10 mph shifting to the north around 10 mph in the afternoon.

East Kaua’i

Today: Partly sunny with chance of showers in the morning, then mostly sunny with slight chance of showers in the afternoon. Highs 75 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows 65 to 77. East winds around 10 mph.

Monday: Mostly sunny with a 20 percent chance of showers. Highs 75 to 87. East winds around 10 mph.

Detailed Forecast

Synopsis

Locally breezy trade winds will persist through tonight, bringing just a few showers, mainly to windward areas. Winds will diminish Monday, and remain light for the remainder of the week. The light winds will combine with a ridge aloft to support a mostly dry weather pattern. A wetter regime may develop by next weekend.

Discussion

Locally breezy ENE trade winds will persist through tonight, bringing just a few showers, mainly to windward areas. Winds will diminish Monday, and will remain light for the remainder of the week. The light winds will combine with a ridge aloft to support a mostly dry weather pattern. Long range guidance suggest a trend toward a wetter pattern may develop by next weekend.
A strengthening and locally breezy trade wind flow is being supported by a ridge far N of the islands, with broad low pressure about 1200 miles NW of Kauai. A strong and low subsidence inversion is the result of a strong mid-level ridge centered directly overhead. End result is a mostly dry trade wind regime, with radar and satellite showing randomly scattered stable and showery low clouds carrying little in the way of rainfall. Little change is expected through tonight.
The low far NW of the area will persist in one form or another for most of the next week as another low develops far NE of the islands. This will lead to a significant reduction in the low-level pressure gradient, with light E to SE winds expected through the week. The ridge aloft will remain overhead, and a mostly dry regime is likely. Best chance for a shower may be over leeward areas in the afternoons as sea breeze convergence drives cloud formation, with a slight chance of windward showers at night.
Although confidence is quite low due to significant spread in the guidance, a slow-moving low aloft may develop near the islands next weekend, potentially leading to a wetter regime.

Aviation

Moderate to locally breezy trades are expected through the rest of today. Winds should diminish Monday and continue to be light for the rest of the week. SHRA and low cigs should favor windward and mauka locations. Brief MVFR conds are possible in SHRA, but VFR should prevail.
No AIRMETs currently in effect.

Marine

Moderate to locally strong easterly trade winds will continue through the day as the upper level high remains north of the islands. A Small Craft Advisory (SCA) is in effect for the typical windier waters and channels around Maui County and the Big Island through 6 pm today. Winds will gradually decrease tonight through the beginning of the week due to two lows forecast to form far northwest and northeast of the waters. The surface ridge will weaken allowing the light to moderate east to southeasterly trades to remain steady through Friday.
A small, short-period north to northwest swell will gradually diminish through the middle of the week, shifting to a more northeasterly direction by Tuesday. Tiny background northwest energy is expected through the week before a small to moderate medium period northeast swell is forecasted by the end of the week. South facing shores will see background south swells that will keep surf from going flat. A small, long-period reinforcement is expected to arrive Monday night and decline through the week followed by another on Friday.
A Coastal Flood Statement (CFWHFO) for all coastal zones is highlighting the fact that higher than forecast water levels are combining with full moon high tides, bringing the potential for minor coastal flooding, mainly during the early morning hours through Monday morning.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov