Photo Credit: Brittney Cruz

West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 83 to 88. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 70 to 76. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Mostly sunny with isolated showers. Highs 81 to 86. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny. Breezy. Highs around 88. Northeast winds up to 20 mph.

Tonight: Partly cloudy. Breezy. Lows around 71. Northeast winds 10 to 20 mph.

Monday: Mostly sunny. Breezy. Highs around 86. Northeast winds 10 to 25 mph.

North Shore

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with showers likely. Lows 69 to 75 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Monday: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to around 67 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Central Maui

Today: Breezy. Mostly sunny with isolated showers. Highs around 87. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Isolated showers. Lows 69 to 74. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Monday: Breezy. Mostly sunny with isolated showers. Highs around 85. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 60 at the visitor center to around 55 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows around 49 at the visitor center to around 45 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 63 at the visitor center to around 59 at the summit. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

East Maui

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with showers likely. Lows 69 to 75 near the shore to around 55 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Monday: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 78 to 83 near the shore to around 67 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Lanai City

Today: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 75 to 84. Northeast winds 10 to 15 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 69. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 73 to 82. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 75 to 86. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 62 to 73. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Monday: Breezy. Mostly sunny with isolated showers. Highs 73 to 84. Northeast winds 15 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds will prevail through much of the next week, with the trades strongest today through Monday as a trough passes by to the south of the islands and a strengthening area of high pressure builds southeastward and closer to the state. Fairly typical trade wind weather will persist over the smaller islands today, although some showery weather will affect windward Kauai at times this morning. More unsettled weather is expected over windward sections of the Big Island however, where showery conditions may linger into this evening. Drier trade wind weather should return statewide by late tonight and continue through Thursday. A more showery trade wind pattern could develop Friday into next weekend as a disturbance aloft moves in.

Discussion

Currently at the surface, a trough of low pressure is located around 225 miles south of the Big Island, while a 1030 mb high is centered 1500 miles north-northwest of Honolulu. The resulting gradient is producing moderate to breezy trade winds across the island chain early this morning. Infrared satellite imagery shows partly to mostly cloudy conditions across the state, with cloud cover most prevalent over windward locales. Radar imagery shows scattered showers moving into windward areas, with a stray shower reaching leeward areas from time to time, with shower coverage the highest over windward sections of Kauai and the Big Island. Main short term concern revolves around rain chances during the next 24 hours or so.
High pressure to the north-northwest of the islands will build southeastward and strengthen during the next couple days, while a trough of low pressure passes steadily westward to the south of the state. This will keep breezy trade winds in place across the island chain through Monday, with a slight easing of the trades into the moderate range expected by Tuesday as the ridge north of the state weakens. A cold front passing by to the distant north will further weaken the ridge north of the islands Wednesday, dropping the trades a notch further. The trades should then begin to increase on Thursday as high pressure strengthens to the northeast of the state, with locally breezy conditions returning Friday into next weekend.
As for the remaining weather details, showery conditions will likely affect windward Big Island through this evening, as a slug of deep tropical moisture moves through. More typical trade wind weather is expected over the smaller islands, although some showery weather may continue across Kauai this morning. More typical trade wind weather should then settle in over the whole state by late tonight, with showers favoring windward and mauka areas, mainly during the overnight and early morning hours and a stray shower reaching leeward areas from time to time. A weakness aloft will develop over the state Friday into next weekend, which could bring a more showery trade wind pattern back to the islands.

Aviation

The clouds and showers moving over Kauai and producing some mountain obscuration should be clearing out soon, but AIRMET Sierra remains in effect for the time being. Have recently cancelled the AIRMET Sierra that was in effect for Oahu as conditions have improved there.
Conditions had deteriorated on the Big Island around midnight prompting AIRMET Sierra for mountain obscuration over the east side. However clouds and showers have recently thinned. Another batch of clouds and showers just southeast of the Big Island could bring another spell of MVFR and/or mountain obscuration, so leaving the AIRMET in place for the time being.
Strong high pressure north of the islands will continue to support breezy easterly trade winds across the region into tomorrow. As such, AIRMET Tango remains in effect for moderate mechanical turbulence downwind of the mountains below 9000 ft, and is expected to continue into at least tomorrow.

Marine

A high pressure ridge far north of the region and a surface trough passing steadily westward, to the south of the island chain, will increase trade wind speeds a bit into Monday. Trade winds in the moderate to strong range will last into Tuesday. Wind speeds may weaken a bit from late Tuesday into Thursday due to a reshuffling of the high pressure centers along the ridge far north of the region. A Small Craft Advisory (SCA) was expanded this morning to cover most of the Hawaiian Coastal Waters and Channels. This SCA will decrease in coverage back to the typical windier waters and channels on Monday as the trough passes slowly west of the area. Trade wind speeds will remain just below SCA thresholds for the windier waters near the eastern islands from Tuesday into Thursday.
The north-northwest swell continues to decline this morning, north shore surf will slowly decrease into Monday. A small north swell will build in from Tuesday night into Wednesday with a small bump in surf heights expected along north facing shores. The south swell will drop slightly today and then fade to background level surf heights through at least Wednesday. The trade wind swell will hold surf heights roughly the same for one more day along east facing shores before decreasing slowly on Monday and Tuesday, and then increase back to near average heights on Thursday or Friday.

HFO Watches/Warnings/Advisories

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

Maui Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov