Photo Credit: Brendan Stephen

West Kaua’i

Today: Partly sunny with scattered showers. Highs 85 to 91 near the shore to around 76 above 3000 feet. Light winds. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Monday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 86 to 91 near the shore to around 77 above 3000 feet. Southeast winds up to 10 mph. Chance of rain 40 percent.

South Kaua’i

Today: Partly sunny with scattered showers. Highs 83 to 91. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with isolated showers. Lows around 73. Northeast winds up to 10 mph. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 83 to 91. East winds up to 10 mph. Chance of rain 40 percent.

Kaua’i Mountains

Today: Mostly cloudy with scattered showers. Highs 74 to 83 in the valleys to around 66 above 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 70 in the valleys to around 59 above 4000 feet. East winds up to 10 mph. Chance of rain 40 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 76 to 84 in the valleys to around 67 above 4000 feet. Light winds. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 77 to 87. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 66 to 73. Southeast winds up to 10 mph. Chance of rain 40 percent.

Monday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 78 to 88. East winds up to 10 mph. Chance of rain 40 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 75 to 87. Northeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 77. Light winds. Chance of rain 40 percent.

Monday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 76 to 87. Light winds becoming east around 10 mph in the afternoon. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Light to moderate trade winds will continue for the next several days, with land and sea breezes dominating. Expect clouds and showers favoring leeward and interior areas each afternoon, then clearing overnight with limited windward showers. A shallow band of moisture will linger around through today. Expect slightly drier conditions to filter in Monday through mid- week, with another round of increased showers possible toward the end of the week.

Discussion

A surface high is centered far west-northwest of the state, with a weak ridge extending eastward just to our north, is producing light to locally moderate trades over the islands. Latest CIMSS precipitable water vapor imagery shows enhanced moisture around the state. Radar imagery shows scattered showers along windward Oahu and the Big Island early this morning with isolated showers elsewhere. Satellite imagery shows low level clouds mainly around the Big Island with a mix of low to mid level clouds over Oahu with mostly clear conditions elsewhere. There is also some high clouds streaming in from the north that will provide a little more cloud cover today for the smaller islands.
As trades remain on the lighter side today, seabreezes should kick in shortly after sunrise today. This will mean an increase of clouds and showers along windward and leeward interior areas in the afternoon. Shortly after sunset, a land breezes will develop at night, with most inland and leeward areas clearing. Background tradewind flow will strengthen slightly tonight and lingering moisture could allow for some clouds and limited showers along windward areas.
Trade winds will trend more to the lighter side Monday through mid week as the weak surface ridge to the north weakens due to a frontal boundary well north of the state sagging southward. The background wind flow will potentially shift out of the east- southeast Monday as the ridge redevelops east of the state. The land/sea breeze pattern will continue through mid week for the most part, with afternoon showers over interior and leeward areas. Despite an overall drying trend, brief periods of slightly heavier rainfall amounts are possible each afternoon, as a weakness develops in the upper level ridge over the state. Land breezes will lead to general clearing and drying conditions at night, with a shower or two still moving into some windward areas.
By the second half of the week, global models continue to show the tail end of a front approaching the western half of the state from the north. Depending how far south this front and associated upper- level troughing make it, we could possibly see a wetter overall pattern develop Thursday into Friday, especially for Kauai and Oahu, along with a brief return of moderate to breezy trades.

Aviation

Light trade winds will continue through the weekend allowing for the development of local land and sea breezes. Expect any clouds and showers that develop over the interior this afternoon to dissipate shortly after sunset. VFR conditions will generally prevail across the state, with brief MVFR conditions possible under passing showers. However, a band of moisture from a remnant front may increase the potential for increased clouds and showers across portions of Kauai and Oahu through the morning hours.
No AIRMETs are currently in effect nor expected today.

Marine

Gentle to moderate trade winds will prevail through tonight the high pressure ridge north of the islands remains weak. A weak frontal system passing far north of the region will continue to disrupt the trade winds through early next week. A stronger ridge will build in far north of the state by Thursday increasing trade winds.
A series of North Pacific swells are due this week, likely leading to the first High Surf Warning event of the season starting on Tuesday. Energy from an approaching northwest swell will lead to above October average north shore surf into Monday. A storm force low, previously West Pacific Typhoon Bolaven, will send a large northwest swell toward the islands early next week. Small, long- period, westerly forerunners may arrive by Monday morning. The larger, long-period northwest swell will build rapidly from Monday night into Tuesday, likely producing High Surf Warning conditions for north and west facing shores from Kauai to Maui from late Tuesday through Wednesday. This northwest swell will slowly decrease through the rest of the week. A Small Craft Advisory will also be issued on Tuesday and Wednesday for seas 10 feet or greater.
Along south facing shores, a series of south-southwest swells will keep surf around October average through much of the week. Small surf heights continue along east facing shores through next Thursday.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov