West Kaua’i

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 69 to 74 near the shore to around 62 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny. Isolated showers in the morning. Highs 84 to 90 near the shore to around 76 above 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly clear. Lows 69 to 74 near the shore to around 61 above 3000 feet. East winds up to 10 mph.

South Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 80 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with numerous showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 74 to 83 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 77 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Partly cloudy with isolated showers. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 64 to 76. East winds 10 to 15 mph. Chance of rain 70 percent.

Thursday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 76. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

The forecast will trend drier for the rest of this week as a weak disturbance aloft lifts away from the state and ridging builds into the region. However, occasional pockets of moisture embedded within moderate to locally breezy trade winds will continue to produce mainly windward and mauka showers for the next several days. Trade wind speeds could decrease even further early next week as an overall drier trade wind pattern continues.

Discussion

This afternoon, latest satellite and radar imagery shows that the enhanced showers and extensive cloud cover observed last night through earlier today have largely diminished. This uptick in showers resulted from instability as a weak disturbance aloft, seen in the 700mb streamlines, approached from the east and moved into the island chain. That weak disturbance aloft is now lifting away from the main Hawaiian Islands as drier, more stable air settles into the region. Meanwhile, surface high pressure centered far northeast of the state remains nearly stationary, maintaining breezy easterly trade wind flow across the island chain this afternoon.
Tonight through the next several days, upper-level ridging will build into the region from the east as the surface high to our northeast remains nearly stationary but weakens slightly. This will result in a slight decrease in trade wind speeds, with prevailing trades in the moderate to locally breezy category. While conditions will begin to trend drier, some lingering instability and pockets of moisture embedded within the trade wind flow will still support typical windward and mauka showers, especially during the overnight through early morning hours each day.
Early next week, relatively little change is expected as the surface high to the far northeast continues to weaken and moves farther eastward away from the Hawaiian Islands. This will weaken the trades even more for the first half of the work week.

Aviation

Breezy trades continue across the Hawaiian Islands through the next several days. AIRMET Tango remains in effect for moderate turbulence below 8000 feet downwind of island terrain on all islands and will continue at least through Thursday morning.
Expect periods of MVFR/IFR conditions within incoming clouds and showers. AIRMET Sierra is posted for tempo mountain obscurations for north through east sections of Kauai, with isolated mountain obscurations for windward sides of the rest of the islands. Elsewhere, VFR conditions are expected to prevail tonight.

Marine

High pressure northeast of the state will drive moderate to locally strong trade winds for the next several days. A weather disturbance passing well north of the area late this weekend should help to ease the pressure gradient and allow trades to gradually ease into early next week. The Small Craft Advisory for the windier waters of Maui County and the Big Island have been canceled due to a gradual weakening of the trade winds, however conditions will remain borderline until later in the weekend.
The current south swell will continue to provide above average surf along south facing shores through the remainder of the afternoon, staying below High Surf Advisory criteria. This swell should gradually fade through Thursday, leaving behind small background energy in its wake. Models indicate another small to moderate sized swell arriving early next week.
Surf along E shores should remain rough and choppy for the next several days but could decrease a notch as the trade winds decrease later this weekend. Surf along N shores remains tiny through the period.
Peak high tides associated with the lunar cycle will cause minor coastal flooding along shorelines and low lying coastal areas through Thursday. The Coastal Flood Statement remains in effect for the daily peak tide each afternoon and may be exacerbated by the current S swell.

HFO Watches/Warnings/Advisories

None.

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