West Side

Today: Sunny. Highs 75 to 86. East winds up to 15 mph.

Tonight: Mostly clear. Isolated showers in the evening. Lows 64 to 72. East winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Tuesday: Sunny. Highs 74 to 85. East winds up to 15 mph.

South Side

Today: Sunny. Highs 77 to 87. Northwest winds up to 15 mph.

Tonight: Mostly clear. Lows 66 to 71. Northwest winds up to 10 mph in the evening becoming light.

Tuesday: Sunny. Highs 75 to 86. Light winds becoming north up to 10 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs around 81 near the shore to around 67 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 68 to 73 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 78 to 83 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny. Highs 81 to 88. Northeast winds up to 15 mph.

Tonight: Mostly clear. Lows around 68. East winds up to 10 mph in the evening becoming light.

Tuesday: Sunny. Highs 80 to 86. Northeast winds up to 15 mph.

Upcountry

Today: Sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 53 to 70. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly clear. Scattered showers in the evening, then isolated showers after midnight. Lows around 45 at the visitor center to around 42 at the summit. East winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny. Scattered showers in the morning. Highs 53 to 68. East winds up to 10 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs around 81 near the shore to around 67 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 68 to 73 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 78 to 83 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Sunny. Highs 69 to 80. Northeast winds up to 15 mph.

Tonight: Mostly clear. Lows 60 to 66. Light winds.

Tuesday: Sunny. Highs 68 to 79. Light winds.

Kaunakakai

Today: Sunny. Highs 70 to 88. East winds 10 to 15 mph.

Tonight: Mostly clear. Lows 56 to 72. East winds up to 15 mph.

Tuesday: Sunny. Highs 69 to 87. East winds up to 10 mph.

Detailed Forecast

Synopsis

A cold front passing far north of the Hawaiian Islands will weaken the high pressure ridge just north of the state, keeping light to moderate trade winds in the forecast lasting into Wednesday. Brief passing showers are possible in this weather pattern favoring the late afternoon to early morning hours. A stronger cold frontal low pressure system moves into the Central Pacific basin on Wednesday, driving the ridge axis directly over the island chain, and producing light east to southeasterly winds. The forward motion of the front will likely stall out and diminish west of Kauai over the weekend.

Discussion

The weather pattern over the Hawaiian Islands this morning appears to be fairly stable. Temperature inversion heights are around the 5,000 to 6,000 foot level, supporting brief passing showers favoring the windward and mountain areas. We continue to see a high pressure ridge just north of the islands with cold frontal systems passing by farther to the north. These cold core low pressure systems will continue to weaken the ridge this week, keeping trade winds in the light to moderate range lasting into Wednesday.
By Wednesday evening, this subtle weather pattern changes once again, as a stronger cold frontal low moves through the Central Pacific basin. Colder air surrounding this system will drive the weakened ridge farther south, with the ridge axis hovering directly over the Hawaiian Islands from Thursday to Friday. Lighter east to southeasterly winds will develop from Thursday onward into the weekend, expanding the coverage of daytime sea breezes to all islands. Not much in the way of showers during this time period as the ridge over the islands keeps conditions fairly stable. One exception to this rule will be along the southeast slopes of the Big Island, where southeasterly wind flow will lift clouds up the slopes of Mauna Loa, enhancing clouds and showers over Kau and Puna Districts.
These lighter winds will continue through the weekend as the forward movement of an approaching cold front appears to stall out as the boundary dissipates just west of Kauai. Light southerly winds may increase shower activity over Kauai and Niihau from Saturday to Sunday. Model solutions are fairly inconsistent from run to run on these enhanced shower impacts. The rest of the state appears on the drier side in an east to southeast wind and a hybrid sea breeze pattern during the day over each island. Another stronger cold front approaching the islands from the west may bring another round of wet weather with southerly winds by early next week, stay tuned.

Aviation

Light to moderate trade winds will continue for the next few days. Terrain sheltered leeward areas will see expanding coverage of daytime sea breezes. Brief passing showers are expected in the later afternoon to early morning hours. TEMPO MVFR is possible in passing showers.
No AIRMETs in effect and none are expected.

Marine

The pressure gradient back to the surface high centered about 1,600 nm northeast of the islands will weaken as the high exits east. Thus, today's moderate to locally fresh easterly trade winds will begin to fall off through the week. A large North Pacific storm will push a cold front in the vicinity of Kauai and Niihau next weekend. The approach of the front will weaken and veer winds more southerly through the holiday. The tail end of this front will likely pass north of the island chain this time next week. A decent size northwest swell passage over Thanksgiving may push seas to near Small Craft Advisory thresholds. A large northwest swell will likely lift seas to SCA heights (10 ft or higher) this time next week.
This morning's moderate size, medium period northwest swell (320-340 degree) will continue to fall through Tuesday. This will result in near head high surf this morning over better northern exposures before falling to waist high by tomorrow. A slightly larger size, long period northwest swell (330 degree) is scheduled to arrive Wednesday, fill in and peak on Thursday. This swell will result in solid High Surf Advisory level surf with the possibility of surf just touching High Surf Warning heights during its peak Wednesday night into Thursday morning. A large storm force low moving up from the West Central Pacific may drive a very large northwest swell toward the islands late this week. As of now, this swell is forecast to arrive early next week and could generate XL size surf along north-facing shores.
Weakened trades will result in a decline of east-facing shore chop.

Fire weather

Winds and humidity levels will remain below critical fire weather thresholds this week. Brief passing showers will trend higher during the typical late afternoon to early morning hours. Temperature inversion heights will range from 5,000 to 6,000 feet elevation today near Maui and the Big Island.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov