Photo Credit: Braden Jarvis

West Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs around 91 near the shore to around 79 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 73 to 78 near the shore to around 64 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Sunny. Isolated showers in the afternoon. Highs around 91 near the shore to around 79 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs around 88. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 71 to 77. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Breezy. Mostly sunny with isolated showers. Highs around 88. East winds 10 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 78 to 85 in the valleys to around 69 above 4000 feet. East winds up to 15 mph. Chance of rain 60 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 78 to 85 in the valleys to around 69 above 4000 feet. East winds up to 15 mph. Chance of rain 40 percent.

North Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 81 to 90. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 67 to 77. East winds up to 15 mph shifting to the southeast after midnight. Chance of rain 30 percent.

Wednesday: Mostly sunny with isolated showers. Highs 81 to 90. East winds up to 15 mph. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 81 to 89. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 78. East winds 10 to 15 mph. Chance of rain 30 percent.

Wednesday: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 81 to 89. East winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

High pressure north-northeast of the islands will keep breezy trade winds blowing through early next week. Relatively dry trade wind weather is expected to prevail, with low clouds and showers favoring windward and mauka areas, primarily at night and during the early morning hours, with a stray shower reaching leeward communities from time to time.

Discussion

Currently at the surface, a 1029 mb high is centered around 1600 miles north-northeast of Honolulu, while the remnant low of former Tropical Cyclone Fernanda is located around 400 miles south- southwest of South Point. The gradient locally is producing moderate to locally breezy trade winds across the island chain early this morning. Infrared satellite imagery shows partly to mostly cloudy conditions in windward areas, with partly cloudy skies in most leeward locales. Radar imagery shows isolated to scattered showers moving into windward slopes and coasts, with mainly dry conditions in leeward locales with the exception of a few showers hugging the leeward Big Island coast. Main short term focus revolves around trade wind trends and rain chances.
Strong high pressure will remain anchored to the north-northeast of the islands through Friday, with the high then weakening as it shifts southward and closer to the islands over the weekend into early next week. Overall, very little change in the overall trade winds strength is expected during the next 7 days, with breezy trade winds prevailing statewide.
As for the remaining weather details, very little change in the overall weather pattern is expected today through early next week, with pockets of moisture periodically moving through the islands. Showers will favor windward and mauka areas, particularly at night and during the early morning hours, with a stray shower occasionally reaching leeward communities.

Aviation

Moderate to breezy easterly trade winds will continue, with clouds and showers favoring windward and mauka areas. Expect periods of MVFR CIGs/VSBYs for windward/mauka areas through the early morning hours. Elsewhere, VFR conditions will prevail.
AIRMET Sierra for mountain obscuration is now in effect for the windward areas of Oahu and Maui, but will likely be dropped by daybreak as conditions steadily improve.

Marine

Persistent high pressure far NNE of the islands will support a seasonable, fresh to strong trade wind flow into next weekend. A Small Craft Advisory will remain posted for the windier zones around Maui and the Big Island for the foreseeable future.
NDBC and PacIOOS buoys around the islands are detecting a mix of swell energy this morning, including a small, medium-period SSE swell, building long-period E swell (generated by Hurricane Hilary), a lingering small long-period SW swell, and short-period E wind waves. Even so, relatively small combined seas of 4 to 7 feet prevail, although likely larger (and unmeasured) in the windier channels between the islands. The E swell will peak near 4 feet into Wednesday, then lower Thursday, with the SSE swell peaking around 2 feet in the short term, then gradually diminishing. Otherwise, no other swell sources are noted.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov