Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny. Highs around 87 near the shore to around 75 above 3000 feet. Light winds.

Tonight: Partly cloudy. Lows 67 to 72 near the shore to around 58 above 3000 feet. Light winds.

Friday: Mostly sunny. Highs around 87 near the shore to around 75 above 3000 feet. Light winds.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Highs around 84. East winds up to 10 mph shifting to the south in the afternoon.

Tonight: Partly cloudy. Lows 65 to 71. Light winds.

Friday: Mostly sunny. Highs around 84. Light winds becoming east up to 10 mph in the afternoon.

Kaua’i Mountains

Today: Partly sunny. Highs 74 to 81 in the valleys to around 65 above 4000 feet. Light winds.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Lows 58 to 63 in the valleys to around 53 above 4000 feet. Light winds.

Friday: Partly sunny in the morning then becoming mostly sunny. Highs 74 to 81 in the valleys to around 65 above 4000 feet. Light winds.

North Kaua’i

Today: Mostly sunny. Highs 77 to 86. Light winds.

Tonight: Partly cloudy. Lows 61 to 71. Light winds.

Friday: Partly sunny in the morning then becoming mostly sunny. Highs 77 to 86. Northeast winds up to 10 mph.

East Kaua’i

Today: Partly sunny. Highs 77 to 85. Light winds.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Lows 59 to 72. Light winds.

Friday: Partly sunny in the morning then becoming mostly sunny. Highs 77 to 85. Northeast winds up to 10 mph.

Detailed Forecast

Synopsis

A surface ridge will remain just north of Kauai during the next couple days, keeping the trades light and allowing for land and sea breezes to form across much of the state. The ridge will lift northward this weekend allowing the trades to gradually strengthen, with moderate to locally breezy conditions returning Sunday through the middle of next week. Very dry conditions will greatly limit shower activity through the weekend, with a slight increase in windward showers expected Monday and Tuesday. A more typical trade wind pattern should return by the middle of next week.

Discussion

Currently at the surface, a east to west oriented ridge of high pressure has settled southward to around 150 miles north of Kauai, and this has weakened the trades with land breezes present in many leeward areas. Infrared satellite imagery shows scattered to broken low clouds across the area resulting in partly to mostly cloudy skies. Radar imagery and rain gage observations show very dry conditions remain in place across the state. Main short term focus continues to revolve around trade wind trends during the next several days.
The ridge of high pressure north of the state will shift southward to a location just north of Kauai today through Friday, keeping the trades light and allowing for land and sea breezes to be common across much of the state. The ridge will begin to lift northward over the weekend allowing the trades to gradually strengthen, with moderate to locally breezy conditions expected Sunday through the middle of next week.
As for the remaining weather details, very stable and dry conditions remain over the island chain, as evident in the sharp trade wind inversions, at or below 4 kft at both Hilo and Lihue during the 12z soundings. Little change in the trade wind inversion is expected through the weekend, which will greatly limit shower activity across the entire state. The trade wind inversion will begin to lift early next week, which should bring a slight increase in trade wind showers Monday and Tuesday, while still remaining drier than normal for this time of year. A more typical trade wind pattern should return by the middle of next week as the trade wind inversion rises further.

Aviation

Trade winds will gradually weaken over the next twenty-four hours as the pressure gradient across the Islands relaxes further. This will allow sea breezes to predominate along leeward coasts in the afternoon and early evening hours. Meanwhile, mid-level ridging building in from the east will make for an increasingly drier air mass later in the week.
A strong inversion aloft around 04 kft will both encourage morning low clouds and inhibit afternoon shower development. Low clouds have persisted overnight across the state, especially along windward coasts of the Big Island and Maui. AIRMET Sierra is currently in effect for mountain obscuration along northeast slopes of the Big Island. Conditions are expected to improve around noon due to daytime heating. Limited shower development is expected over interior portions of the Big Island in the late afternoon and early evening.

Marine

The ridge to the north of the islands continues to slowly sink southward, weakening the trade winds over the region. Expect winds to remain below Small Craft Advisory (SCA) levels through the end of the week. Over the weekend, the ridge will lift to the north, allowing moderate trade winds to build back. Guidance shows the potential for a SCA to return for the typical windier waters around Maui County and the Big Island by Sunday.
The south Pacific remains active sending consecutive pulses to south facing shores of Hawaii over the first half of the month. Surf has leveled off overnight but another south- southwest swell is expected to arrive later today and peak Friday. A moderate long period south- southwest swell will build into this weekend, peaking Sunday night into Monday near High Surf Advisory levels. Late next week, a moderate long period south swell is expected to reach HSA levels. Stay tuned as the storm continues to develop.
The current small northwest swell continues to decline. Another small pulse from the northwest is expected to build through this afternoon keeping surf elevated. Wind waves for east facing shores have diminished significantly and this trend looks to continue into the weekend.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov