Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 90 near the shore to around 78 above 3000 feet. Northeast winds up to 10 mph shifting to the southeast in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with isolated showers. Lows around 75 near the shore to around 64 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Thursday: Partly sunny with isolated showers. Highs around 90 near the shore to around 79 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny with scattered showers. Highs 82 to 90. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 75. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Thursday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 83 to 91. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Mostly cloudy. Showers likely in the morning, then scattered showers in the afternoon. Highs 76 to 87 in the valleys to around 67 above 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 73 in the valleys to around 61 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 76 to 88 in the valleys to around 68 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 78 to 91. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 68 to 75. Southeast winds up to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 79 to 91. East winds up to 15 mph. Chance of rain 40 percent.

East Kaua’i

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 74 to 87. Northeast winds up to 10 mph shifting to the east in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 67 to 78. Northeast winds up to 10 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will hold through the weekend. A more typical dry season trade wind pattern is expected to return today and hold through Saturday with passing showers focused over windward slopes.

Discussion

Satellite and radar imagery early this morning shows an area of numerous clouds and showers moving mainly Oahu and Kauai. This enhanced area of showers will continue to provide an uptick in clouds and showers through the morning hours as it moves from east to west. Overnight rainfall totals along windward zones have reached at least .20 of an inch with some select leeward areas receiving at least .01 of inch.
A 1031 mb high sitting far north of the state will continue to drive moderate to locally breezy trade winds through the weekend with only some slight variations as the high circulates north of the state and fluctuates in strength. The high is expected to weekend late over the weekend and into early next week but winds may stay breezy locally due to a disturbance passing south of the islands keeping the gradient tight.
As far as rainfall, expect a drying trend later this afternoon due partially with the diurnal pattern and a drier, more stable air mass filtering in. CIMSS precipitable water vapor imagery shows the tail end of above normal moisture currently passing over the state with near to below normal moisture levels upstream that will start to filter in today. In addition 700 mb trough will push west today while more stable conditions build in, limiting cloud depth.
By Saturday, the GFS global models show an upper level low dropping southward within the vicinity of the state around Monday while the EC models has the lo lingering just west of the state. These differences continue to create some uncertainty with the forecast during this time. If the GFS scenario pans out it could mean we will see an increase of shower coverage as early as Sunday. Stay tuned for more details.

Aviation

A stable, moderate to breezy trade wind flow will prevail during the next couple of days. Stable conditions will prevail, with only limited areas of low ceilings and temporary MVFR conditions over windward areas. Aside from afternoon clouds over Kona slopes of the Big Island, VFR conditions will prevail.
AIRMET Tango for low-level turbulence over and downwind of terrain will likely remain in effect during the next couple of days. No other AIRMETS are currently in effect.

Marine

High pressure north and northeast of the state will keep moderate to locally strong trade winds in place through the weekend. A Small Craft Advisory (SCA) is now in effect for the typically windy waters around Maui and the Big Island through 6 AM Friday. The SCA may eventually need to be extended through the weekend.
East shore surf will hold near seasonal levels through Thursday, then slowly lower Friday through early next week. A mix of southeast, south and southwest swells will keep small surf rolling into south facing shores through Monday. A slight bump in south shore surf is possible around Tuesday or Wednesday of next week as a slightly larger long-period southwest swell moves through. North shore surf will remain very small through the weekend. A nice bump in north shore surf is possible Tuesday and Wednesday of next week as a 3 to 4 foot medium to long-period northwest swell arrives.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Friday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov