Photo Credit: Brendan Stephen

West Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 89 near the shore to around 78 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 72 near the shore to around 61 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers. Highs around 90 near the shore to around 78 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny with isolated showers. Highs 82 to 90. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 72. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 82 to 90. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Mostly sunny with scattered showers. Highs 76 to 87 in the valleys to around 67 above 4000 feet. East winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 71 in the valleys to around 59 above 4000 feet. East winds around 10 mph becoming up to 15 mph after midnight. Chance of rain 50 percent.

Monday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 87 in the valleys to around 68 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

North Kaua’i

Today: Mostly sunny with isolated showers. Highs 78 to 89. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 66 to 74. East winds around 10 mph. Chance of rain 50 percent.

Monday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 78 to 90. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 87. East winds around 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 76. East winds around 10 mph. Chance of rain 50 percent.

Monday: Partly sunny with scattered showers. Highs 74 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate trade winds will continue through the week. Showers will favor windward and mountain areas, especially in the overnight to early morning hours. A slightly drier trade wind pattern is expected to persist today, followed by subtle wetter trends for the rest of the week.

Discussion

A band of low level clouds and showers will move into windward and mountain sections this morning, keeping scattered showers in the forecast along these north and east facing mountain slopes. Drier trends will return a few hours after sunrise this morning and last through tonight.
In the big picture, the high pressure ridge north to northeast of the Hawaiian Islands will begin to weaken slightly today as a cold frontal system passes through the Central Pacific basin. Trade wind speeds will decrease to moderate levels across the state lasting through the rest of this week.
In the rainfall forecast, we continue to see subtle changes in the day to day shower activity over each island. Brief drying trends will develop through late tonight. Additional bands of clouds, likely associated with the remnants of an old East Pacific frontal boundary, will then drift into the state on the trade winds from Monday through Wednesday. Expect increasing shower trends during this time period, favoring windward and mountain areas in the overnight through early morning hours.

Aviation

Surface high pressure far northeast of the state will continue to help drive moderate trades across the islands through the forecast period. Expect limited showers along windward and mauka this morning, becoming more isolated by this afternoon. Brief MVFR possible within any heavier showers, otherwise VFR conditions prevail.
No AIRMETs are currently in effect.

Marine

A ridge of high pressure north and northeast of the islands will keep moderate to locally fresh trades in place through late this week. The Small Craft Advisory for the typically windy waters around Maui and the Big Island has been cancelled.
A small, medium period north-northwest swell will gradually decline today through Monday as it shifts more northerly. A similar or slightly larger, medium period northwest swell should arrive Tuesday, peak late Tuesday and Tuesday night, then decline as it shifts more northerly Wednesday and Thursday. Several small swells from the north should maintain some small surf along north facing shores Friday through next weekend.
A series of small long-period southwest swells should provide some small but inconsistent surf along south facing shores during the next couple days. A slightly larger south-southwest swell should fill in Tuesday, hold through Wednesday, then gradually decline through the rest of the work week. A small to moderate sized long- period south-southwest swell will gradually fill in late Saturday and Saturday night, then peak at 3 to 4 foot swell heights next Sunday and Monday.
East shore surf will remain small through most of this week, although select spots with more northerly exposure could see some of the north swells throughout the week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov