Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 87 to 92 near the shore to around 78 above 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Mostly clear with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 72 near the shore to around 63 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 86 to 92 near the shore to around 77 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Kaua’i

Today: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 85 to 91. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. Lows 71 to 76. Northeast winds around 15 mph. Chance of rain 70 percent.

Sunday: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 84 to 91. Northeast winds around 15 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Breezy. Occasional showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 76 to 86 in the valleys to around 68 above 4000 feet. East winds 10 to 20 mph. Chance of rain near 100 percent.

Tonight: Mostly cloudy. Breezy. Showers likely in the evening, then occasional showers after midnight. Lows around 69 in the valleys to around 61 above 4000 feet. East winds 10 to 20 mph. Chance of rain 90 percent.

Sunday: Breezy. Cloudy with occasional showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 85 in the valleys to around 68 above 4000 feet. East winds 15 to 20 mph. Chance of rain 90 percent.

North Kaua’i

Today: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 89. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers likely after midnight. Lows 67 to 75. East winds 10 to 15 mph. Chance of rain 70 percent.

Sunday: Partly sunny with occasional showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 78 to 89. East winds 10 to 15 mph. Chance of rain 90 percent.

East Kaua’i

Today: Cloudy with showers likely in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 88. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then occasional showers after midnight. Lows 67 to 78. Northeast winds 10 to 15 mph. Chance of rain 90 percent.

Sunday: Cloudy with occasional showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 75 to 88. Northeast winds 10 to 15 mph. Chance of rain 90 percent.

Detailed Forecast

Synopsis

Breezy trade winds will continue for the foreseeable future. The trade wind flow looks to trend a little more showery today into Sunday, with windward showers occasionally spreading leeward. Otherwise, low clouds and brief showers will generally favor windward and mauka areas during night and morning hours.

Discussion

Slow-moving surface high pressure to the distant N of the islands will support breezy trade winds through the next week. A nearby mid- level ridge will support a strong and relatively low subsidence inversion (currently based between 5000 and 6000 feet) that will limit rainfall coverage and amounts. However, the inversion will remain sufficiently high to allow brief windward showers to develop, mainly during nights and mornings. The Big Island's leeward slopes will see afternoon and evening clouds that will drop a few showers before gradually dissipating through the early morning hours.
Current satellite images show scattered to broken stable and showery low clouds streaming over the islands from the E, with radar detecting randomly distributed light showers. An area of increased PWAT currently crossing 150W is expected to arrive later today into Sunday, bringing the potential for increased windward shower coverage, with a few showers spreading leeward. GOES-18 ProxyVis imagery (courtesy CIRA) indicates the cloud field in this area is dominated by showery open-cell cumulus elements, lending credence to the thought that shower activity will increase in a relatively high PoP / low QPF regime. Typical diurnal variations in cloud cover are expected, leading to better rainfall chances during nights and mornings overall.

Aviation

The breezy trade winds are expected to persist today. Low clouds and showers will continue to be transported by the low-level trade wind flow into the windward sides of the islands through this morning. This may produce periods of MVFR conditions due to lower ceilings / reduced visibilities over some windward sections. Otherwise, expect VFR conditions to prevail across most of the state.
AIRMET Tango remains in effect for Tempo moderate low-level turbulence leeward of the higher terrain on all islands. This AIRMET will likely be needed through this evening based on the latest forecast. AIRMET Sierra may be needed for mountain obscuration later this morning if low clouds and showers become widespread over some windward sections.

Marine

Surface high pressure will remain north of the state and will continue to produce moderate to locally strong tradewinds blowing across the region through the middle of next week. A Small Craft Advisory is in effect through the weekend for the typical windy areas around Maui County and the Big Island and will likely continue through the foreseeable future.
No significant swells are expected over the next seven days with only small surf heights forecast into early next week. A small background long period south (190 degree) swell will move into the islands late Sunday through Tuesday with only a small increase in the surf heights along south facing shores. Surf along east facing shores will remain small and choppy, driven by trade wind wave energy.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov