Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 15 mph shifting to the southwest in the afternoon. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated showers. Lows 69 to 74 near the shore to around 60 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs around 85. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 67 to 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs around 85. East winds 10 to 15 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then frequent showers after midnight. Lows 60 to 65 in the valleys to around 55 above 4000 feet. East winds up to 15 mph. Chance of rain 80 percent.

Saturday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 78 to 87. East winds up to 15 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 73. East winds up to 10 mph. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers. Highs 78 to 87. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 78 to 86. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows 61 to 75. Northeast winds around 10 mph. Chance of rain 50 percent.

Saturday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 86. East winds around 10 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A ridge of high pressure north of the state will keep trade winds blowing through the next 7 days, although they will be somewhat lighter through early Saturday allowing for some localized land and sea breezes. Pockets of moisture will get caught up in the trades through the period, bringing some showery conditions to windward areas at times and sending a few showers into leeward communities as well. There remains potential for some heavier showers, particularly over the eastern islands, as the remnant trough, of what is now Invest 94E, passes by to the south of the state around the middle of next week.

Discussion

Currently at the surface, a 1022 mb high is centered around 1000 miles northeast of Honolulu, while the remnant trough of former tropical cyclone Jova is located around 300 miles east of Hilo. The gradient across the state continues to produce moderate trade winds early this morning, with localized land breezes in some of the more sheltered leeward areas. Infrared satellite imagery shows partly to mostly cloudy conditions, with cloud cover the greatest over western portions of the state. Radar imagery shows scattered showers moving into windward portions of the islands, with some of these showers spilling over into leeward communities. Main short term focus revolves around rain chances and trade wind trends during the next few days.
A ridge of high pressure north of the islands will keep a generally moderate trade wind flow in place during the next couple days, with localized sea breezes expected in the more sheltered leeward areas each day. The trades may be slightly weaker tonight into Saturday as the remnant trough of former tropical cyclone Jova moves from east to west through the islands. The trades should restrengthen from east to west across the state Saturday afternoon and Saturday night, with moderate to locally breezy conditions then expected Sunday through late next week.
As for the remaining forecast details, a pocket of drier air with precipitable water values around 1.2 to 1.3 inches is evident just upstream of the islands, and this should bring much drier conditions to the state today after a rather showery night. The drier weather appears brief however, as the remnant trough of former tropical cyclone Jova should bring a return of showery trade wind weather tonight into early Saturday, with a drier airmass moving in from east to west across the state Saturday afternoon and Saturday night, then holding through the day Sunday. A fairly typical trade wind pattern is expected to return Sunday night and hold through late next week, with showers favoring windward and mauka areas particularly at night and during the early morning hours, with a few showers reaching leeward communities at times. There remains potential for some heavier showers, particularly over the eastern islands, as the remnant trough, of what is now Invest 94E, passes by to the south of the state around the middle of next week.

Aviation

Light to moderate easterly trades will persist, with clouds and showers favoring windward slopes and coasts. Some of these showers will push into leeward areas over the western end of the state as a band of moisture moves through this morning. Although conditions should temporarily improve through the day as some drier air moves in, a return of showery conditions with periods of MVFR CIGs/VSBYs appears likely tonight into Saturday as another area of moisture moves in.
AIRMET Sierra is in effect for tempo mountain obscuration across windward sections of the islands, which may continue through daybreak for the western end of the state. Conditions will steadily improve from east to west through the day as the drier air arrives.

Marine

A weakening high pressure ridge far north of the state will keep gentle to moderate trade winds in the forecast into Saturday. A remnant trough of former Tropical Cyclone Jova will move through the islands Saturday bringing an increase in shower activity as it moves through. Trade winds will increase into the fresh to locally strong range late Saturday and Saturday night as the remnants of Jova pass to the west of the state. A Small Craft Advisory may be needed for typical windy waters around Maui and the Big Island starting late Saturday and lasting through the first half of next week.
For the south shores, another small long period south swell will arrive this weekend. Longer period forerunners will begin to arrive in Hawaii by early Saturday morning, with swell energy peaking Sunday, and then slowly decreasing into next week.
Surf along east facing shores will remain on the small side through the weekend. No significant swells are expected to affect the north and west facing shores through the forecast period.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov