Photo Credit: Jason Weingardt

West Kaua’i

Today: Partly sunny with scattered showers. Highs around 83 near the shore to around 69 above 3000 feet. South winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers. Lows around 69 near the shore to around 59 above 3000 feet. South winds around 10 mph. Chance of rain 20 percent.

Sunday: Partly sunny in the morning then becoming mostly sunny. Highs around 82 near the shore to around 69 above 3000 feet. South winds 10 to 15 mph.

South Kaua’i

Today: Partly sunny with isolated showers. Highs 79 to 84. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Lows around 67. Southwest winds 10 to 15 mph.

Sunday: Partly sunny in the morning then becoming mostly sunny. Highs 78 to 83. South winds 10 to 15 mph.

Kaua’i Mountains

Today: Partly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 80 in the valleys to around 65 above 4000 feet. Southwest winds 10 to 20 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers. Lows 61 to 66 in the valleys to around 57 above 4000 feet. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Sunday: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 73 to 79 in the valleys to around 63 above 4000 feet. South winds 10 to 15 mph. Chance of rain 20 percent.

North Kaua’i

Today: Partly sunny in the morning, then mostly sunny with isolated showers in the afternoon. Highs 74 to 82. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening, then mostly cloudy with isolated showers after midnight. Lows 61 to 70. Southwest winds around 10 mph. Chance of rain 20 percent.

Sunday: Partly sunny in the morning then becoming mostly sunny. Highs 73 to 82. South winds 10 to 15 mph.

East Kaua’i

Today: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 75 to 83. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers. Lows 62 to 72. Southwest winds around 10 mph. Chance of rain 20 percent.

Sunday: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 72 to 82. South winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

South winds are expected today with a stalling to the west of the state this weekend. Clouds, and a few showers, may impact the western end of the state today, and again Monday and Tuesday. The front could bring some unsettled weather, and windier conditions Wednesday and Thursday as it moves down the island chain.

Discussion

No major changes to the forecast with the morning package. For today and tonight, the PoP and associated fields were nudged towards the NBM No changes to the forecast or the forecast philosophy this evening. Also not expecting any significant changes to the forecast with the morning package.
Southerly winds will continue into the first part of the new week. A weakening front to the northwest of the state will slowly approach the islands, and is expected to stall west of the state this weekend. A ridge over the southern end of the island chain is helping to keep dry and stable conditions in place. The nearby front will at times send some clouds and showers over the western islands over the next couple of days.
The front is expected to weaken further on Sunday, allowing the ridge to edge northward. However, the front will be invigorated by a passing longwave trough late Sunday into Monday. This will strengthen the south to southwest winds to moderate to fresh levels Monday and Tuesday while the frontal cloud and rain band edges closer to Kauai forcing the ridge to the eastern end of the state. Showers will likely increase a little bit across Kauai and Oahu Monday and Tuesday from current levels as winds and upstream moisture from the southwest boost up. The front is forecast weaken as it moves down the island chain Wednesday through Thursday night. Rainfall and southwest winds may initially be heavy/strong as the front moves across Kauai to Maui County, but weaken as it reaches the Big Island Thursday night, and then dissipates across the Big Island on Friday. Winds will shift northwesterly behind the front, and then shift back southerly as the front dissipates and a ridge builds in.

Aviation

A ridge remains extended over the state today with a stationary front northwest of Kauai. Between these two features, light to moderate southerly winds can be expected to continue. While ridging will help to limit cloud cover and shower activity over the next 24 hours, satellite imagery shows some low level clouds and showers near Kauai and Oahu this morning that have developed along an area of prefrontal convergence. Even though the front northwest of Kauai is not expected to make any progression towards the state today, prefrontal convergence may lead to occasional periods of MVFR conditions…particularly across Kauai. Otherwise, VFR conditions should prevail.
AIRMET Sierra for mountain obscuration is in effect for the island of Kauai. This will likely be cancelled later this morning as conditions gradually improve.

Marine

A surface ridge over the central portion of the island chain will produce southerly winds through early next week. Gentle to moderate southeast to south winds around the Big Island veer out of the south to southwest near Kauai, where locally fresh winds will be possible today and again late Sunday as fronts stall to the northwest. Southwest winds are expected to increase late Tuesday or Wednesday, possibly to Small Craft Advisory strength, as another front nears Kauai. The front will likely move down the island chain late next week.
North and west facing shores will trend up to High Surf Warning (HSW) levels through the day as long period forerunners of the swell have been registering at PacIOOS buoy 51201 (Waimea Bay) over the early morning hours. With the offshore NOAA buoys 51101 and 51001 northwest of the islands continuing to rise, expect a steady rise in surf along north and west facing shores of most other islands through the day that will peak well above HSW later today and Sunday. Due to the significant westerly component of this swell, shadowing could produce varying surf heights on Oahu and Maui County, and west facing shores of the Big Island all the way up to Mahukona will experience significant impacts, including overwash onto vulnerable coastal roadways and beaches. Tracking the offshore buoys, a Small Craft Advisory (SCA) has been issued for all waters exposed to the swell on Saturday and Sunday as seas rise above the 10 feet SCA criteria. Seas will build over Kauai this morning and spread down the island chain coinciding with the rising swell. This swell will decline Sunday night and Monday, followed by a smaller pulse of west- northwest swell Tuesday and Wednesday.
Surf along east facing shores will remain small into next week due to a lack of easterly trade winds upstream of the islands. A small pulse of south-southwest swell will fade Saturday, with little to no southerly swell expected through the rest of the week.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 PM HST Sunday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
High Surf Warning from 6 PM this evening to 6 PM HST Sunday for Kona, Kohala, Big Island South.
High Surf Advisory until 6 PM HST Sunday for Lanai Leeward.
Small Craft Advisory until 6 PM HST Sunday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov