Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny. Highs 86 to 91 near the shore to around 77 above 3000 feet. North winds up to 10 mph shifting to the southwest in the afternoon.

Tonight: Partly cloudy. Lows around 71 near the shore to around 61 above 3000 feet. Northeast winds up to 15 mph.

Tuesday: Mostly sunny. Breezy. Highs around 89 near the shore to around 77 above 3000 feet. East winds up to 20 mph.

South Kaua’i

Today: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 82 to 89. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tuesday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 82 to 89. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 74 to 84 in the valleys to around 67 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 70 in the valleys to around 59 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Breezy. Mostly cloudy with scattered showers. Highs 74 to 85 in the valleys to around 67 above 4000 feet. East winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 77 to 89. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 74. East winds up to 15 mph becoming around 10 mph after midnight. Chance of rain 50 percent.

Tuesday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 90. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 75 to 86. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 76. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly cloudy with scattered showers. Highs 74 to 86. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A stable, moderate trade wind pattern will prevail today with mainly light showers focused over the windward and mountain areas. Increasing trade winds and slightly wetter conditions are expected through the rest of the week.

Discussion

As expected, no changes to the forecast, with little change in the latest model runs.
A broad high pressure system remains over the northern Pacific, with a weak area of low pressure due north of the islands. As the low lifts northward today, the pressure gradient over the islands will strengthen some, leading to a small uptick in the trades. A mid- to upper-level ridge remains over the islands providing a very stable airmass which will continue to limit shower activity today.
Trades will increase some more tonight and Tuesday, and a batch of increased moisture riding in on the the trades will provide a little boost to the shower activity. Heading into the middle of the week, the trades are expected to increase to locally breezy levels as the above mentioned ridge builds while the low lifts northward.
A mid-level trough approaching from the southeast Tuesday night will lead to borderline Wind Advisory conditions on the highest summits of the Big Island. This trough will weaken as it passes over the islands Thursday, resulting in a weakening of the summit winds. This trough will have a minimal impact on the general stable airmass over the islands.
Breezy trade winds, and a somewhat dry and stable pattern of mainly windward showers will then prevail Friday into next weekend.

Aviation

Moderate to locally breezy trade winds are expected to continue through today and increase slightly heading into tomorrow. Low clouds and showers will bring brief periods of MVFR conditions to windward and mauka areas, but overall, VFR conditions are expected to generally prevail.
No AIRMETs are currently in effect. However, AIRMET Sierra for tempo mountain obscuration may be needed if shower coverage increases.

Marine

High pressure northeast of the state will continue to generate moderate to locally fresh trade winds today, as a trough remains anchored far north of the state. The aforementioned area of high pressure is forecast to strengthen over the next couple of days and bring moderate to locally strong trade winds from Tuesday onward. A Small Craft Advisory will likely be issued for the typical windy waters around Maui County and The Big Island by Tuesday.
Small surf will hold along south facing shores through much of this week as the current small south- southeast swell slowly declines. A small south-southwest swell will fill in tonight, which should maintain small surf along south facing shores through the work week. Into the long range, a deep low pressure system currently southeast of New Zealand will send a decent run of south swells beginning this weekend. Surf heights may reach advisory thresholds of 10 feet along south facing shores during its peak Sunday into Monday.
Surf along north and east is expected to gradually taper off on today. However, surf along east facing shores will steadily increase during the second half of the week as the trades strengthen locally and upstream of the state.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov