Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Partly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs around 80 near the shore to around 69 above 3000 feet. Northwest winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers. Lows 61 to 68 near the shore to around 51 above 3000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs around 80 near the shore to around 69 above 3000 feet. North winds up to 10 mph shifting to the east in the afternoon. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs around 77. West winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows 58 to 67. Northwest winds up to 15 mph in the evening becoming light.

Tuesday: Partly sunny. Scattered showers in the afternoon. Highs around 77. Light winds becoming south around 10 mph in the afternoon. Chance of rain 30 percent.

Kaua’i Mountains

Today: Partly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs 68 to 74 in the valleys to around 60 above 4000 feet. West winds up to 15 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with isolated showers. Lows 50 to 58 in the valleys to around 46 above 4000 feet. Northwest winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 68 to 74 in the valleys to around 60 above 4000 feet. North winds up to 10 mph. Chance of rain 50 percent.

North Kaua’i

Today: Breezy. Partly sunny with isolated showers. Highs 70 to 80. West winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers. Lows 55 to 66. West winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 70 to 80. West winds up to 15 mph shifting to the north in the afternoon. Chance of rain 40 percent.

East Kaua’i

Today: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 69 to 79. Northwest winds up to 15 mph shifting to the north in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy early in the evening, then mostly cloudy with isolated showers in the late evening and overnight. Lows 51 to 69. Northwest winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 69 to 79. Northwest winds up to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

The wet pattern will continue over the eastern end of the state today as a cold front around Maui County continues eastward. Meanwhile, light to moderate west-northwest winds with drier air filling in from west to east will continue in the wake of the front as high pressure builds north of the state. Expect a more typical trade wind pattern to return with showers favoring windward and mauka locations Wednesday through the second half of the week.

Discussion

Updated to correct Watch/Warning/Advisory section.
The short-term guidance remains in good agreement and depicts the wet pattern persisting today over the eastern end of the state due to an upper trough to the north and its attendant surface front slowly advancing down the island chain. Radar imagery showed the back edge of the moderate showers with decent rainfall rates along/ahead of the front around Maui early this morning beginning to weaken. The latest rainfall summary depicted 24-Hr rainfall totals (through 2 AM HST) ranging from 3 to 5 inches on Kauai to 1 to 2 inches over Oahu and Maui County. In addition to the wet conditions, expect a wintry mix over the Big Island summits this morning with warning level westerly winds. Elsewhere, light to moderate west-northwest winds and drier conditions have begun to fill in from west to east. Dewpoints are forecasted to dip into the upper 50s to low 60s this afternoon, which will limit rainfall chances. The drying trend will continue over the eastern end of the state on Tuesday as high pressure builds to the north and the fronts slips east of the area. A return of a more typical trade wind pattern with clouds/showers favoring windward areas is anticipated Wednesday through the second half of the week.

Aviation

A quick-moving cold front will exit Hawaii to the northeast today. Clearing has already begun on Kauai. Frequent rain showers possibly mixed with isolated thunderstorms will persist across the central Islands this morning then taper off from the west in the afternoon. The front is weakening as it presses eastward, so the heaviest showers are not expected to reach the Big Island.
Meanwhile, east-southeast flow in advance of the front will carry repeated bands of light showers towards the Big Island with the greatest impact being felt along the windward coast south of Laupahoehoe tonight.
AIRMET Sierra for mountain obscuration is currently in effect for Maui and Molokai. Conditions are expected to improve in the early afternoon.
Moderate upper level turbulence could redevelop across the state later today as the upper level trough to the northwest of Hawaii digs southward.
Occasional light rime icing is expected in layered clouds above 15 kft. Conditions are expected to persist into the evening hours.

Marine

A front over Maui County will continue to push slowly eastward today and tonight, then stall out and slowly dissipate near the Big Island Tuesday and Wednesday. Light to moderate west to northwest winds will fill in behind the front today, with winds becoming rather light for Tuesday. Moderate north to northeast winds will fill in by late Wednesday, with fresh to strong trades expected Thursday and Friday as high pressure builds eastward well to the north of the state. The trades appear to ease a bit over the weekend as the high to the north weakens.
A Small Craft Advisory remains posted for the Alenuihaha Channel and leeward Big Island waters today due to funneling effects between Maui and the Big island. A SCA has also been issued for 10 foot seas around Kauai today.
Surf along north and west facing shores will trend up today as a northwest swell builds. Surf may flirt with low end advisory levels along north facing shores of the smaller islands late today and tonight, but should hold just below the advisory threshold of 15 feet. Surf along east facing shores will remain very small through the week. Small, medium to long period south swells will keep some small surf rolling into south facing shores through the week.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 AM HST Tuesday for Haleakala Summit.
High Wind Warning until 6 AM HST Tuesday for Big Island Summits.
Winter Weather Advisory until 11 AM HST this morning for Big Island Summits.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Alenuihaha Channel, Big Island Leeward Waters.

Data Courtesy of NOAA.gov