Photo Credit: Braden Jarvis

West Kaua’i

Today: Partly sunny with scattered showers. Highs around 80 near the shore to around 68 above 3000 feet. Northwest winds up to 10 mph shifting to the west in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with isolated showers. Lows around 61 near the shore to around 50 above 3000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers. Highs around 78 near the shore to around 66 above 3000 feet. North winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny with scattered showers. Highs around 79. Light winds. Chance of rain 40 percent.

Tonight: Mostly cloudy with isolated showers. Lows 57 to 62. Northeast winds up to 10 mph. Chance of rain 20 percent.

Thursday: Mostly sunny. Highs around 77. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

Kaua’i Mountains

Today: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs 67 to 75 in the valleys to around 62 above 4000 feet. Light winds. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 50 to 55 in the valleys to around 44 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 65 to 73 in the valleys to around 60 above 4000 feet. North winds up to 10 mph. Chance of rain 30 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 72 to 79. Northwest winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 53 to 62. North winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 70 to 77. North winds 10 to 15 mph. Chance of rain 30 percent.

East Kaua’i

Today: Mostly cloudy with numerous showers. Highs 72 to 79. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 51 to 63. North winds up to 10 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 70 to 77. North winds 10 to 15 mph. Chance of rain 30 percent.

Detailed Forecast

Synopsis

An approaching front will keep winds light and variable through today. Some pre- frontal showers will develop today along with interior showers from daytime heating this afternoon. The cold front will move through the island chain later today through Thursday while weakening. Breezy northeast winds will follow the front ushering in cooler and drier weather through the rest of the week, except for portions of the Big Island and Maui where moisture from the front will linger.

Discussion

Clouds and showers have increased over and near Kauai during the past couple of hours, in-line with latest model guidance. Radar indicates mostly light scattered showers with a couple of isolated heavy showers. These clouds and showers are progressing towards Oahu and will bring scattered moderate to locally heavy rain over Oahu during the morning commute. Surface winds will remain light ahead of the front today, and the convective response Tuesday adds confidence that another round of interior clouds/showers can be expected this afternoon.
A cold front will move through Kauai and Oahu tonight and early morning Thursday before weakening and drifting over Maui and the Big Island through Thursday. Shower activity will increase for north and northeast facing slopes and coasts ahead of the front. Model solutions show that the chance for measurable rain will be highest near the Big Island and parts of Maui county as moisture from the front lingers Friday through the weekend. Meanwhile, the western islands may see very little rain as the drier and slightly cooler post- frontal airmass settles in behind the front. In addition, mid and upper level ridging will build, further increasing stability as a weak surface high builds north of the state. Northeast winds will but gusty behind the front then become more moderate Friday through the weekend and the shift more easterly.

Aviation

A weak cold front approaching the islands from the northwest will keep wind speeds in the light to moderate range for the next few days. A weak disturbance moving over Kauai and Oahu will produce brief MVFR conditions over portions of each island. Land and sea breezes will develop with clouds and isolated showers developing each afternoon over island mountain and interior sections. VFR conditions will prevail.
No AIRMETs currently in effect. AIRMET Sierra might be issued later this morning for tempo mountain obscuration near Kauai or Oahu.

Marine

A front will push down the island chain late today through Thursday night, with moderate to fresh northerly winds filling in behind the front. Winds will shift northeast at moderate to fresh levels on Friday as a weak high builds northwest of the state. Winds will ease into the light to moderate range and shift to a more typical east-northeasterly trade wind direction over the weekend into early next week as the weak high passes by to the north of the state. Winds are expected to remain mostly below Small Craft Advisory (SCA) thresholds through early next week. SCA level seas will likely impact portions of the marine area as a large northwest swell moves through Thursday into early Saturday.
The current moderate sized long period northwest swell will gradually decline today. A new more significant northwest swell is expected to build late tonight and Thursday morning, then peak at warning levels Thursday afternoon through Friday along most north and west facing shores of the smaller islands. Advisory level surf appears likely with this swell along west facing shores of the Big Island Thursday night through Friday night as well. This swell will decline Friday night and Saturday, with a reinforcing northwest swell building Saturday night, keeping some moderate sized surf in place along north and west facing shores through early next week.
Small surf will persist along south facing shores through Saturday, with a slight boost possible Sunday through early next week. East shore surf will trend down during the next couple days, then remain well below normal through early next week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov