Photo Credit: Jason Weingardt

West Kaua’i

Today: Partly sunny. Isolated showers in the morning, then numerous showers in the afternoon. Highs around 84 near the shore to around 74 above 3000 feet. Southeast winds up to 10 mph. Chance of rain 70 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 70 near the shore to around 56 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs around 84 near the shore to around 74 above 3000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny with isolated showers. Highs around 82. East winds around 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with scattered showers. Lows 63 to 69. East winds around 10 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 82. East winds 10 to 15 mph. Chance of rain 30 percent.

Kaua’i Mountains

Today: Mostly cloudy. Isolated showers in the morning, then numerous showers in the afternoon. Highs around 77 in the valleys to around 66 above 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 59 in the valleys to around 51 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers. Highs around 77 in the valleys to around 66 above 4000 feet. East winds up to 10 mph. Chance of rain 30 percent.

North Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 77 to 83. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers early in the evening, then partly cloudy with isolated showers in the late evening and overnight. Lows 59 to 68. East winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 77 to 83. East winds up to 15 mph. Chance of rain 30 percent.

East Kaua’i

Today: Partly sunny with isolated showers. Highs 75 to 81. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows 57 to 70. East winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 81. East winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 30 percent.

Detailed Forecast

Synopsis

Moderate trades will prevail over the eastern islands through the first half of the work week, while lighter trades over the western islands allow for some leeward land and sea breezes. Relatively dry weather will persist through Tuesday, with a few showers affecting windward areas overnight into the early morning hours and developing over interior and leeward areas each afternoon. The trades will rebound Tuesday night and Wednesday, bringing a transition over to more typical trade wind weather. The trades will become breezy Thursday through next weekend, and the trade wind showers may increase as well due to a disturbance aloft moving over the islands.

Discussion

Currently at the surface, a weakening front is located around 450 miles west-northwest of Kauai, while a 1031 mb high is centered around 1600 miles northeast of Honolulu. Moderate trade winds prevail in unsheltered areas over the eastern end of the state, while lighter trades persist over the western islands. Infrared satellite imagery shows a combination of high and low clouds resulting in mostly cloudy conditions across the state. Radar imagery shows a few light showers moving into windward areas, with mainly dry conditions elsewhere. Main short term focus continues to revolve around trade wind trends and rain chances during the next few days.
A front northwest of the islands will weaken into a trough and edge slowly eastward during the next couple days. Little change is expected in the overall wind forecast, with moderate trades holding on over the eastern end of the state, while lighter trades prevail over the western islands, allowing some leeward sea and land breezes to develop. We should see the trades start to rebound beginning Tuesday night as the trough west of the state begins to shift slowly westward. Moderate to locally breezy trades should overspread the island chain by late Wednesday, with the trades becoming breezy Thursday through the weekend.
As for the remaining weather details, relatively dry conditions should generally prevail across the island chain through Tuesday. Brief passing showers will be possible in windward areas overnight into the early morning hours, with a few showers developing over interior and leeward areas each afternoon. A few showers could be a bit more robust over Kauai and potentially Oahu this afternoon, as some shortwave energy grazes by just to the north. We should see a transition over to more typical trade wind weather Tuesday night and Wednesday, with wetter trade wind conditions potentially developing Friday through the weekend as upper troughing sets up over the state.

Aviation

Light to moderate ESE winds will continue through Tuesday and VFR conditions are expected to generally prevail. However, low clouds and light showers are persisting across windward portions of Kauai, Maui and the Big Island early this morning, bringing periodic MVFR conditions to these areas. As such, AIRMET Sierra for tempo mountain obscuration is in effect.
High clouds will continue to stream across the Hawaiian Islands today as an upper level jet streak moves in from the west. Tempo moderate turbulence around FL300 to FL380 may accompany this feature…and AIRMET Tango may be needed through the day.
Otherwise, with the lighter ESE flow, afternoon sea breeze activity is expected across wind- sheltered areas, with some inland/leeward cloud buildups and a few light showers possible. However, the high clouds may inhibit heating over land, and therefore limit sea breeze activity.

Marine

High pressure far northeast of the state will continue to slide east while a weak dying front to the northwest edges slowly eastward. Winds will ease through Tuesday and the Small Craft Advisory has been cancelled for all zones this morning. By mid- week, high pressure will rebuild to the northeast transitioning back to typically fresh to locally strong trade winds. The SCA will likely go back up for the typical windy waters around Maui County and the Big Island.
North facing shores will remain small through the week with tiny to small medium period background energy. Surf along east facing shores will continue to decline as winds begin to taper off through Tuesday. A small long period south- southwest pulse will fill in through the day, peak Tuesday and ease Wednesday for south facing shores. Surf heights along the south facing shores should remain near or slightly below seasonal norms.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov