Photo Credit: Jason Weingardt

West Kaua’i

Today: Partly sunny with scattered showers. Highs around 86 near the shore to around 74 above 3000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows around 69 near the shore to around 58 above 3000 feet. Light winds. Chance of rain 40 percent.

Wednesday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 85 near the shore to around 74 above 3000 feet. Light winds. Chance of rain 50 percent.

South Kaua’i

Today: Partly sunny with scattered showers. Highs 82 to 87. West winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Lows 67 to 72. Northwest winds up to 10 mph. Chance of rain 30 percent.

Wednesday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 84. West winds up to 10 mph shifting to the south in the afternoon. Chance of rain 30 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 73 to 80 in the valleys to around 67 above 4000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening. Lows around 63 in the valleys to around 55 above 4000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 73 to 79 in the valleys to around 67 above 4000 feet. West winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 77 to 84. West winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Scattered showers early in the evening. Lows 62 to 70. West winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Wednesday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 77 to 84. Light winds. Chance of rain 50 percent.

East Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 85. Southwest winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows 61 to 73. Light winds. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 84. Light winds. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A weakening cold front will stall out near Oahu and Molokai and diminish today. Expect light southwesterly winds to bring a few showers into the southern slopes of most islands with added interior showers in a sea breeze pattern during the day on Tuesday. Land and sea breezes will continue from Wednesday through Friday. Weak trade winds will build in over the weekend as another weak cold front moves into and stall out near Kauai and Oahu, enhancing shower activity over Kauai, Oahu and possibly Molokai from Saturday to Sunday. Light to locally moderate trade winds along with sheltered sea breezes are forecast next week Monday and Tuesday.

Discussion

A combination of satellite and radar imagery this morning shows several bands of showers moving into southern Oahu and Molokai this morning. A few of these stronger shower bands may briefly reach Lanai and West Maui around sunrise. Rainfall amounts will remain on the lighter side as more stable conditions develop through the day. Strong upper level winds will keep wind advisories posted for the highest peaks of Mauna Loa and Mauna Kea on the Big Island today. Wind speeds this afternoon at summit level may fall just below advisory thresholds.
A land and sea breeze weather pattern will continue for most islands through Saturday. Brief pop up showers are possible in the afternoon to early evening hours due to day time heating and sea breeze wind convergence bands. Overall weather conditions will be fairly stable tonight through the end of the week. Land breezes at night will clear out clouds over the islands.
A weak cold front will move into Kauai by Saturday morning with a period of increasing clouds and showers over the Garden Isle. Some prefrontal shower bands may set up as far east as Molokai this weekend. Maui and the Big Island will remain fairly dry as the forward movement on the front stalls out over the northwestern islands. This frontal boundary diminishes by Sunday, allowing light to locally moderate trade winds to filter back into the region. Day time sea breezes will continue along leeward and terrain sheltered western slopes of each island in a hybrid light wind pattern.

Aviation

A weakening front will move through Oahu today and stall out and dissipated in the vicinity of Molokai tonight. Rather light winds will prevail allowing for overnight land breezes and daytime sea breezes in most areas. Scattered showers along with some reduced cigs and vsbys can be expected along and near the front, with prevailing VFR conditions expected elsewhere.
AIRMET Sierra remains in effect for mountain obscuration over Oahu and Molokai. Conditions should improve later today.
AIRMET Tango remains in effect for moderate upper level turbulence from Molokai eastward to the Big Island. Conditions should improve prior to daybreak Tuesday.

Marine

Moderate to fresh south- southwest winds associated with a front near Oahu will diminish today as the front stalls and weakens over Oahu/Maui County. A return of light and variable winds will allow daytime sea breezes and overnight land breezes to form near the coasts later this afternoon through the rest of the week. The background flow will shift out of the northeast to east through the second half of the week and potentially increase into the light to moderate range for most waters. Another front is forecast to approach Friday, potentially reaching Kauai over the weekend. If the boundary settles southward into Kauai, moderate to fresh northeast winds could return over the weekend as the ridge noses eastward behind the boundary to the north.
Based on latest available observations the north-northwest swell (330-340 degrees) is leveling off. Surf heights along north and west facing shores should stay just below advisory levels. The generation source of this swell will stall around a 1000 NM north- northwest of the area over the next day or two, keeping surf heights elevated through much of the week. Given the proximity of this fetch to the state, expect the peak swell period to hover within the 12-14 sec band initially, with some shorter period energy mixed in through this event.
Surf along south facing shores will remain rough today due to a mix of short period wind waves associated with the aforementioned south-southwest winds and a small, long-period south-southwest swell. A larger south-southwest swell is expected to arrive Wednesday, which will hold through the second half of the week. A similar source is possible Sunday into early next week due to the consistent late season activity within our swell window near New Zealand.
Surf along east facing shores will remain small through the weekend due to the light winds locally and upstream across the eastern Pacific.
Water levels are running significantly higher than predicted around Kauai, which is leading to localized nuisance flooding reports during high tide. As a result, a Coastal Flood Statement has been issued and remains in effect through this afternoon. Most impacts in the vulnerable locations will occur around noon during the daily peak high tide once again Tuesday. This will become a statewide concern this upcoming weekend during the peak monthly tides.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST this evening for Big Island Summits.

Data Courtesy of NOAA.gov