Photo Credit: Braden Jarvis

West Kaua’i

Today: Sunny. Highs 86 to 91 near the shore to around 77 above 3000 feet. Northeast winds up to 10 mph shifting to the south in the afternoon.

Tonight: Mostly clear. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds up to 15 mph.

Wednesday: Sunny. Highs 87 to 92 near the shore to around 77 above 3000 feet. East winds up to 15 mph.

South Kaua’i

Today: Mostly sunny. Isolated showers in the morning. Highs 81 to 90. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 74. Northeast winds around 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 82 to 90. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 74 to 86 in the valleys to around 66 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows 64 to 71 in the valleys to around 59 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 86 in the valleys to around 67 above 4000 feet. Northeast winds up to 20 mph becoming 10 to 15 mph in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 76 to 89. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 66 to 74. East winds up to 15 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 77 to 89. East winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 30 percent.

East Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 74 to 87. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 77. North 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 75 to 87. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

As an upper level low near the state moves off to the northeast and the surface ridge begins to reestablish itself over the region, a more stable moderate to locally breezy trade wind pattern can be expected over the next couple of days with low clouds and brief showers favoring windward and mauka areas. Then trades will weaken briefly early this weekend as a cold front approaches from the north and then dissipates.

Discussion

The upper level low that has been over the state the past few days will quickly lift northeast of the state and bring slightly more stable trade wind conditions to the island chain through the rest of the week. However, mid level ridging will have a hard time building overhead as a broad region of weak troughing persists until this weekend as the short wave trough to the north gets absorbed into the longwave trough and moves eastward, and a weak mid level low/trough to the south moves off to the west.
The surface ridge will reestablish itself over the region and maintain generally moderate to locally breezy trades through Thursday. In this pattern, low clouds and brief showers will favor windward and mauka areas as batches of low level moisture are brought in on the trades, particularly during the late night/early morning periods. Then trades will weaken in response to a frontal system that will approach and dissipate to the north of the state Friday into Saturday, possibly allowing for land and sea breeze development across the areas that are typically more sheltered from the trades. This would allow for some leeward interior cloud build up during the afternoon hours and clearing overnight. Trades will then strengthen back to moderate levels by early next week as the aforementioned front dissipates and the surface pressure gradient restrengthens over the area.

Aviation

Moderate to locally breezy trades expected over the next couple of days. SHRA and low cigs will will bring brief periods of MVFR conds to windward and mauka areas. VFR should prevail elsewhere.
No AIRMETs are currently in effect.

Marine

A high pressure ridge far north of the state will continue to be weakened by cold frontal systems prowling across the Central Pacific basin this week. Therefore gentle to fresh trade winds will continue into next weekend, slightly below Small Craft Advisory levels in the windier eastern waters and channels.
A small long-period north-northwest swell moving through Hawaiian waters will slowly decline over the next few days, keeping surf elevated along north facing shores into Wednesday.
A medium to long period south swell, rolling in roughly 1 foot above model guidance at the PacIOOS Lanai buoy this morning. This swell will also slowly decline trough the first half of this week, elevating surf heights along south facing shores into Wednesday. The latest swell guidance shows yet another smaller long period south swell filling in on Thursday, holding through Friday, and then gradually declining over the weekend.
Surf along west facing shores will be influenced by a mix of both the north and south swells through Wednesday. Surf along east facing shores will be rough and choppy in the gentle to fresh trade wind pattern.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov