Kauai Weather

West Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 79 to 85 near the shore to around 71 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 64 to 71 near the shore to around 59 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Monday: Sunny. Highs 79 to 87 near the shore to around 72 above 3000 feet. East winds 10 to 15 mph.

South Kaua’i

Today: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 84. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 69. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny. Isolated showers in the morning. Highs 78 to 85. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly cloudy. Occasional showers in the morning, then numerous showers in the afternoon. Highs 69 to 77 in the valleys to around 61 above 4000 feet. East winds up to 15 mph. Chance of rain 80 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then scattered showers after midnight. Lows 60 to 68 in the valleys to around 57 above 4000 feet. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 70 percent.

Monday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 71 to 80 in the valleys to around 63 above 4000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

North Kaua’i

Today: Breezy. Partly sunny with numerous showers. Highs 71 to 82. East winds up to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 61 to 70. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 70 percent.

Monday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 83. East winds 10 to 15 mph. Chance of rain 40 percent.

East Kaua’i

Today: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 69 to 81. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 73. Northeast winds around 10 mph. Chance of rain 50 percent.

Monday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 71 to 83. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Synopsis

A front dissipating over the western end of the state, coupled with an upper level trough moving down the island chain, will enhance trade wind showers today. A ridge building north of the islands behind the front will bring trade winds to the region for the start of the new year.

Discussion

No significant changes to the forecast over the next couple of days. The forecast was updated to bring it in line with the latest National Blend of Models (NBM), with little difference between the global models in the short term. This resulted in a decrease in the PoPs over the next couple days, beginning this afternoon, which seems to be in ine with the front dissipating.
No real changes to the forecast philosophy through Thursday. Lingering clouds associated with the dissipating front are over the smaller islands. Radar continues to show fast moving showers moving in on the trade wind flow, with some heavier showers likely the result of the upper level trough. The upper level trough is over the central islands early this morning, and will continue to quickly move down the island chain today, and is expected to the east late this afternoon.
A high pressure ridge north of the islands will then sustain moderate to locally breezy trade winds into the new year. A front passing north of the islands Wednesday will weaken the trades a bit, but a new high moving north of the islands will keep that period brief. Another stronger front approaching from the northwest on Thursday will veer the surface winds to the southeast and then south. But the global models are in good agreement with the southern end of this front washing out before it reaches the islands. Yet another front on the heels of that front looks to reach the islands over the next weekend. There is general agreement with the global models, with some differences in timing. Details will be worked out with future model runs.
A hot spot over Halemaumau Crater on the Big Island continues to be seen on infrared satellite imagery. The University of Hawaii (UH) Vog Model shows that SO2 emissions have cleared out of the smaller islands and should remain confined to portions of the Big Island and the waters to the southwest through Tuesday night. Based on the wind forecast, that trend should continue.

Aviation

A weak dissipating front over the western end of the state continues to bring low clouds and scattered showers. Expect areas of MVFR cigs across Kauai and local MVFR cigs over windward Oahu. VFR conditions to prevail elsewhere with isolated showers. Trade winds will continue to strengthen overnight bringing a return of clouds and showers that are focused over windward and mauka areas.
AIRMET Sierra for tempo mountain obscuration is in effect for Kauai and windward Oahu through the morning and likely extended through the day. No other AIRMETs currently in effect.

Marine

The current northwest (310-330) swell will continue to gradually decline through midweek. The High Surf Advisory for west facing shores of the Big Island has been cancelled. A more moderate northwest (300-320) swell is expected to arrive later in the week and could produce advisory level surf on exposed north and west facing shores of Kauai, Oahu, or Maui. Surf along south and east facing shores is expected to remain small through the week.
Fresh to locally strong trade winds have returned in response to high pressure building in to the north of the islands. The Small Craft Advisory (SCA) is now in effect through this afternoon for the waters surrounding Kauai and through tomorrow afternoon for the typically windier waters around Maui County and the Big Island. The SCA could need to be further extended if strong high pressure persists over the northeast Pacific.

Fire weather

No critical fire weather conditions are expected for the next seven days. Expecting trade winds to become established across the islands from north to south through the rest of this weekend, with some enhanced trade wind showers. A more typical trade wind pattern is expected Monday through Thursday.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Big Island Windward Waters.
Small Craft Advisory from 6 PM this evening to 6 PM HST Monday for Maui County Windward Waters.
Small Craft Advisory until 6 PM HST Monday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Kauai Now Weather is brought to you by Blue Hawaiian Helicopters.

Data Courtesy of NOAA.gov