Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Sunny. Isolated showers in the morning. Highs around 86 near the shore to around 73 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 70 near the shore to around 60 above 3000 feet. Northeast winds 10 to 15 mph decreasing to up to 15 mph after midnight.

Friday: Sunny with isolated showers. Highs 84 to 89 near the shore to around 74 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 79 to 87. Northeast winds 10 to 20 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated showers. Lows around 71. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Breezy. Partly sunny with scattered showers. Highs 79 to 87. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Breezy. Partly sunny with scattered showers. Highs 70 to 81 in the valleys to around 63 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 69 in the valleys to around 56 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Friday: Breezy. Partly sunny with scattered showers. Highs 71 to 82 in the valleys to around 64 above 4000 feet. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 73 to 86. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows 64 to 72. East winds up to 15 mph. Chance of rain 50 percent.

Friday: Mostly sunny with scattered showers. Highs 74 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 70 to 84. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 75. North winds 10 to 15 mph. Chance of rain 40 percent.

Friday: Partly sunny with scattered showers. Highs 72 to 84. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A weak cold front will stall and dissipate across the central islands later today and continue to bring persistent showers along and ahead of its frontal boundary, along with breezy northeast winds statewide. Breezy trades with periodic showers will continue into next week. An upper level low developing southeast of the Big Island this weekend may help to enhance trade wind showers.

Discussion

Satellite and radar imagery show a weak front draped across the central islands, with persistent showers streaming in along and ahead of the frontal boundary. Breezy to locally strong northeast winds are filling in behind the front along with strengthening northeast trades ahead of it, the latter of which will continue to deliver persistent showers to the central islands and the Big Island through tonight. Most of these showers are passing over the island terrain, bringing wet conditions across windward, mauka and leeward areas. So far these showers have been benign, but if they continue to train over the same areas and bring persistent moderate to heavy rainfall, localized flooding will be possible.
The leading edge of the front is now moving into Maui County early this morning and is expected to dissipated later today. The focus for showers will also shift slightly southeast along with the front and then remnant moisture will continue to filter in across the central part of the state on the breezy northeasterly trades through the rest of the week.
Models show an upper low will dig south of the Big Island and then lift northwest along the island chain late this week and into the weekend. However, available moisture may be the limiting factor in shower development through the weekend and into early next week, making pinpointing where showers fall across the island chain a bit tricky. But as pockets of atmospheric moisture move through, increased instability from the low aloft may help to enhance trade wind showers this weekend into early next week.

Aviation

A shallow band of moisture accompanying a cold front nearing Maui County this morning, combined with gusty northeast winds, will continue to generate showery conditions over windward slopes from Oahu to the Big Island. These conditions support AIRMET Sierra for mountain obscuration remaining in effect for these windward areas, potentially persisting through a good portion of the day as this boundary stalls. Drier and more stable air trailing the front has moved over Kauai, which will limit cloud/shower coverage.
AIRMET Tango remains in effect due to low-level turbulence over and downwind of terrain. Moderate turbulence between FL250 and FL350 associated with an upper trough is also expected through the period.

Marine

A weakening front will stall out and gradually dissipate in the vicinity of Maui County through Friday. High pressure building in behind the front to the distant northwest, will lift northeast and merge with a new high over the weekend. Trade winds will remain steady at fresh to strong levels through early next week, with some of the windier channels seeing near Gale force winds at times. A Small Craft Advisory remains in effect for most waters through 6 PM Friday. The SCA will likely need to be expanded to include the typically windier areas around Maui and the Big Island through early next week.
Surf along north and west-facing shores will hold steady today, with the current north-northwest swell then slowly lowering through Friday. A new long-period northwest swell will arrive on Friday, keeping surf up through Saturday, before slowly lowering on Sunday. A pair of back to back moderate sized long-period northwest swells will arrive during the early to middle part of next week, with the latter swell potentially bringing advisory level surf to north and west facing shores on Wednesday.
Surf along east-facing shores will remain elevated and choppy through the middle of next week due to the strong trade winds.
Surf along south-facing shores will remain small and near the seasonal average through the middle of next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Friday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov