West Kaua’i

Tonight: Partly cloudy with scattered showers. Lows around 70 near the shore to around 60 above 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 82 to 89 near the shore to around 75 above 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tuesday Night: Partly cloudy with scattered showers. Lows 67 to 72 near the shore to around 60 above 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

South Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 88. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows around 70. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Tonight: Mostly cloudy with numerous showers. Lows 61 to 68 in the valleys to around 58 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 74 to 81 in the valleys to around 65 above 4000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 70 percent.

Tuesday Night: Breezy. Mostly cloudy with numerous showers. Lows 62 to 68 in the valleys to around 57 above 4000 feet. East winds up to 20 mph. Chance of rain 70 percent.

North Kaua’i

Tonight: Mostly cloudy with numerous showers. Lows 63 to 71. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 85. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 63 to 71. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Tonight: Mostly cloudy with numerous showers. Lows 63 to 74. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tuesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 72 to 84. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 63 to 74. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Breezy trades deliver showers windward and mauka through the week.

Discussion

Strong mid-level ridging positioned north of the islands supports a corridor of active subsidence in maintenance of the rather uniform 7kft trade wind inversion evident on this morning's soundings. The batch of moisture that brought showers to much of Oahu this morning now resides over and upstream of Kauai where trades will remain on the wetter side for the next several hours. Breezy trades will usher this moisture west of island during the first half of tonight. Stable trades then prevail with little in the way of change through at least Thursday.
The resident subtropical jet remains a fixture through the week mainly serving to funnel pockets of high clouds across area skies. A potively tilted mid/upper trough axis remains anchored along the northern periphery of this jet and is presently positioned well west of the islands. As the week progresses, however, this feature will evolve eastward tending to close off and deepen with time. This will assist in slightly weakening the local pressure gradient as subtle surface pressure falls commence leading to slightly weakened trades. The low latitude origin of the low will limit available instability, but it will nonetheless weaken the inversion and will likely give existing trade wind showers a boost as early as Thursday night or Friday.

Aviation

VFR from Oahu through Big Island as breezy, stable trades prevail. An area of enhanced moisture will bring MVFR to windward and interior sections of Kauai for the next several hours before trades finally usher it west of the area. VFR then prevails areawide for the second half of the night through Tuesday afternoon with MVFR limited to isolated instances within heavier showers.
AIRMET Sierra remains in effect for windward Kauai.
AIRMET Tango remains in effect for moderate lee turb.

Marine

Fresh to locally strong trade winds will persist through much of the week as as an area of high pressure remains far northeast of the state. A Small Craft Advisory (SCA) covers the typical windy waters near Maui and the Big Island through Tuesday. This SCA will likely be extended through mid to late in the week.
The current moderate period south-southwest swell will bring elevated surf to south facing shores through tonight, then slowly decline through mid-week. By the end of the week, only small background south swell will exist.
Surf along east-facing shores will be rough and choppy due to the breezy trade winds through the week. A series of small northwest swells will keep small surf in place along north facing shores through the week.

HFO Watches/Warnings/Advisories

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

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