Photo Credit: Jason Weingardt

West Kaua’i

Today: Sunny in the morning, then partly sunny with isolated light showers in the afternoon. Highs 86 to 91 near the shore to around 77 above 3000 feet. East winds up to 15 mph shifting to the southeast in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening, then partly cloudy with isolated showers after midnight. Lows around 70 near the shore to around 61 above 3000 feet. Northeast winds around 10 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 85 to 90 near the shore to around 76 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Mostly sunny with isolated light showers. Highs 84 to 90. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 71. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 83 to 90. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Partly sunny. Scattered light showers in the morning, then isolated light showers in the afternoon. Highs 76 to 85 in the valleys to around 68 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers. Highs 75 to 84 in the valleys to around 67 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated light showers. Highs 78 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated light showers. Highs 76 to 87. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 64 to 76. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 86. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will focus low clouds and isolated to scattered light showers over windward and mauka areas, especially during night and morning hours. Leeward communities will be mostly dry, but afternoon clouds and a few showers will develop across leeward shores and slopes of the Big Island.

Discussion

There is little change in forecast philosophy from last evening. A persistent surface ridge well north of the islands continues to drive moderate to breezy trade winds across local waters and will keep this flow in place through the forecast period. Satellite loop shows an area of patchy broken low clouds, embedded within trade flow, moving westward across Kauai and surrounding waters. Scattered low clouds to clear skies are noted across the remaining islands this morning. Radar shows isolated to scattered light showers within this scarce cloud cover. Models show our airmass will remain stable as a mid-level ridge southeast of the Big Island builds north over the chain, keeping a low and strong subsidence inversion in place into next week. This will cap cloud development and keep showers on the light side.
Expect little change from the current weather pattern into the weekend, except for a forecast trade wind speed bump toward the end of the week. Low clouds riding the trade flow will generate a few light showers across windward areas, while leeward areas stay mostly dry. Expect increased leeward clouds each afternoon, especially on the Big Island, where a few showers will develop. An upper trough passing over the islands on Thursday will likely deliver some high clouds and may trigger a slight increase in showers. Moisture associated with the remnants of former east Pacific Hurricane Adrian may arrive within trade flow late in the weekend, bringing increased windward showers.

Aviation

Moderate easterly trade winds will continue through the 24-hr forecast period and beyond, with clouds and showers favoring windward and mauka locations. Periods with MVFR CIGs/VSBYs are possible in and around passing showers this morning, especially over the western end of the state where a band of low clouds is moving through. Elsewhere, VFR conditions will prevail.
AIRMET SIERRA is in effect for north through east sections of the western end of the state for mountain obscuration above 2000 ft due to clouds and showers. This will likely be cancelled later this morning as the band of low clouds shifts west of Kauai.

Marine

A surface ridge will remain far north of the state and maintain moderate to locally strong trade winds throughout the week. A Small Craft Advisory (SCA) is in place over the typically windier waters around Maui County and the Big Island through Wednesday. This SCA will likely need to be extended beyond Wednesday, since the locally strong trade winds are expected to persist and strengthen slightly in the second half of the week.
Surf along all shores are expected to remain tiny through Friday. Small south and southeast swells will maintain small background surf along south facing shores. In the long range, a series of small to moderate south to south-southwest swells are expected starting this weekend and continuing through the first half of next week.
North facing shores may see a slight pulse out of the north- northwest Wednesday or Thursday. A larger north-northwest swell is possible this weekend, which could produce small surf along north and west facing exposures. East facing shores will remain small through the week before gradually building to modest heights later this week.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov