Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 87 to 92 near the shore to around 77 above 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers. Lows around 73 near the shore to around 62 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 89 near the shore to around 78 above 3000 feet. East winds up to 10 mph. Chance of rain 50 percent.

South Kaua’i

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 82 to 90. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

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

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 82 to 90. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Mostly cloudy with scattered showers. Highs 76 to 87 in the valleys to around 68 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 72 in the valleys to around 60 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 75 to 87 in the valleys to around 67 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 78 to 89. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 74. East winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 78 to 89. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 74 to 87. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 77. Northeast winds around 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 75 to 87. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

High pressure north of the islands will keep moderate trades blowing through Saturday, with perhaps a slight easing Sunday through early next week. Rather dry trade wind weather will prevail through the weekend, with showers favoring windward slopes and coasts. A slight increase in trade wind showers will be possible next week as remnant moisture from some old fronts moves into the region from the east.

Discussion

Currently at the surface, a west to east oriented ridge of high pressure is located around 700 miles north of Honolulu, and is driving moderate trade winds across the island chain early this morning. Cira ProxyVis satellite imagery shows mostly cloudy conditions in windward areas, with partly cloudy skies in most leeward locales. Radar imagery shows scattered showers moving into windward slopes and coasts, with a decaying shower occasionally spilling over into leeward areas. Main short term focus revolves around trade wind trends and rain chances.
The ridge of high pressure north of the islands will remain nearly stationary through Friday night, maintaining moderate trade winds across the island chain. The trades will likely be light enough that some localized sea breezes develop each afternoon in the most sheltered leeward locations. The trades appear to ease slightly this weekend through early next week, as a series of fronts approach and stall out to the distant northwest.
As for the remaining weather details, the combination of mid-level ridging over the islands and deep tropical moisture remaining displaced to the south, will keep rather dry trade wind weather in place through at least the weekend. Scattered showers will favor windward and mauka areas, with a decaying shower reaching leeward areas at times. Some deeper moisture associated with the remnants of some old fronts may get caught up in the trades next week, bringing an increase in trade wind shower coverage.

Aviation

Moderate to locally breezy trades will continue for the next several days. SHRA and low cigs should mainly be focused on windward and mauka locations. Brief MVFR conds are possible in SHRA, otherwise VFR should prevail.
No AIRMETs in effect.

Marine

A weak high north of the state will maintain moderate to locally fresh trades through the rest of the week. Overnight ASCAT observations showed winds have eased below Small Craft Advisory (SCA) criteria. Latest model guidance still shows some zones briefly reaching or near SCA criteria at times but is not persistent enough to warrant the continuation of the SCA, thus the SCA has been cancelled. A series of fronts approaching from the far northwest will aid in weakening the high to the northeast this weekend and persisting into next week. Trades will gradually weaken into the gentle to locally fresh range by Sunday and hold at these levels through early next week.
The moderate, long period northwest swell (320 to 330 degrees) that brought near advisory level surf yesterday morning will continue to gradually decline through Friday. A small, medium to short period north- northwest swell (340 to 350 degrees) will build in Friday providing a small, short lived boost to north and select west facing shores surf this weekend.
Multiple small, south and southwest swells (220 to 200 degrees) are expected now into early next week. The current small, long period southwest swell will continue to fade today along with an overlapping tiny, short period southwest swell. A couple of tiny, long period southwest (220 degrees) swells are then expected Friday through the weekend keeping small surf along south facing shores. The next small, long- period south- southwest swell (200 degrees) is expected to fill in Monday and peak Tuesday into Wednesday that could bring near to slightly above average surf along south facing shores.
East facing shores will remain small through early next due to the lack of strong trades locally and upstream.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov