Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny with isolated showers. Highs around 82 near the shore to around 72 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 72 near the shore to around 62 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny with isolated showers. Highs around 82 near the shore to around 72 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 80. Northeast winds 15 to 20 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 69 to 75. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Monday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 80. East winds 15 to 20 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Mostly cloudy. Breezy. Showers in the morning, then scattered showers in the afternoon. Highs 71 to 76 in the valleys to around 63 above 4000 feet. East winds 10 to 25 mph. Chance of rain 80 percent.

Tonight: Mostly cloudy. Breezy. Numerous showers in the evening, then showers after midnight. Lows 62 to 67 in the valleys to around 56 above 4000 feet. East winds 10 to 25 mph. Chance of rain 80 percent.

Monday: Mostly cloudy. Breezy. Showers in the morning, then scattered showers in the afternoon. Highs 71 to 76 in the valleys to around 63 above 4000 feet. East winds 10 to 25 mph. Chance of rain 80 percent.

North Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 71 to 81. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 72. East winds 10 to 20 mph. Chance of rain 70 percent.

Monday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 71 to 81. East winds 10 to 20 mph. Chance of rain 50 percent.

East Kaua’i

Today: Breezy. Mostly cloudy with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 72 to 81. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 63 to 75. East winds 10 to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 72 to 81. East winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Breezy to locally strong trades will continue through early next week. A typical trade wind pattern will prevail during this time with showers focused over windward and mauka zones, especially overnight and during the early morning. Trades will gradually ease around the midweek time frame as a cold front passes to the north.

Discussion

Breezy trade winds will continue into the first half of next week as a persistent subtropical high moves slowly eastward. Typical trade wind conditions will be the result, with the best chance for showers favoring windward and mauka locations overnight through the morning hours as pockets of moisture move through. A weak low aloft just north of Hawaii combined with an area of moisture moving through will lead to periods of enhanced showers.
For the second half of the week, guidance remains in decent agreement and depicts the high weakening as a cold front passes to the north allowing the trades to relax beginning around Wednesday. The tail end of the aforementioned front passing to the north is projected to hangup north of the state through this time. This pattern transition would result in mostly dry conditions prevailing with gentle to moderate trades, except for afternoon showers that manage to develop over localized leeward areas where local sea breezes may form.

Aviation

Breezy to locally strong trades will continue into Monday, with showers favoring windward and mauka zones overnight through the morning hours. Some showers will lead to MVFR CIGS/VSBYS for brief periods as they pass through. Otherwise, VFR conditions will prevail.
AIRMET Tango remains in effect below 9000 feet over and immediately south through west of mountains. This AIRMET will likely remain in effect through the rest of the weekend with breezy trade winds persisting.

Marine

A 1029 mb surface high centered far N of the islands will move slowly ESE through Monday, with little overall change in the current strong to near-gale force trade wind regime. A Small Craft Advisory (SCA) is posted for all waters through today, and has been extended into Wednesday for the windiest zones around Maui and the Big Island. Additional zones may need to be extended beyond this afternoon.
The high will weaken far NE of the area from Monday night through Thursday, with its associated ridge shunted toward the islands. This will occur as low pressure fills the central N Pacific and sends a front toward the area. Trade winds will ease in response, with lightest winds expected on Thursday. A new high building NW of the islands will turn the winds toward the NE Thursday/Friday, potentially pushing the dissipating front over Kauai waters.
A long-period S swell will support surf heights above the seasonal average today, then diminish Monday through Wednesday, with small surf then prevailing along S facing shores into next weekend. The locally strong trade winds over and upstream of the islands will support short-period wind wave development that will lead to choppy surf along E facing shores, with E shore surf diminishing after midweek. Surf along N facing shores will be small for the next several days, but back-to-back medium-period NNW swells are expected from Thursday through Monday. Potential exists for surf heights to reach High Surf Advisory levels along exposed N facing shores with the second swell next weekend.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Wednesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Small Craft Advisory until 6 PM HST this evening for all remaining Hawaiian coastal waters.

Data Courtesy of NOAA.gov