West Side

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 77 to 84. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 68 to 73. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Monday: Sunny and breezy. Highs 77 to 83. Northeast winds 10 to 25 mph.

South Side

Today: Mostly sunny. Breezy. Highs 76 to 86. North winds up to 20 mph increasing to 10 to 25 mph in the afternoon.

Tonight: Partly cloudy. Breezy. Lows 66 to 76. North winds 10 to 25 mph.

Monday: Sunny and breezy. Highs 76 to 86. Northeast winds 10 to 25 mph.

North Shore

Today: Breezy. Partly sunny with isolated showers. Highs 80 to 85 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 69 to 75 near the shore to 49 to 54 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 65 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Central Maui

Today: Mostly sunny. Breezy. Highs 79 to 86. Northeast winds 10 to 20 mph.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Lows 66 to 71. Northeast winds 10 to 20 mph.

Monday: Mostly sunny. Breezy. Highs 78 to 86. Northeast winds 10 to 20 mph.

Upcountry

Today: Mostly sunny. Breezy. Highs around 62 at the visitor center to around 65 at the summit. East winds up to 20 mph.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 41 to 56. East winds up to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Highs around 61 at the visitor center to around 66 at the summit. Northeast winds up to 20 mph shifting to the east in the afternoon.

East Maui

Today: Breezy. Partly sunny with isolated showers. Highs 80 to 85 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 69 to 75 near the shore to 49 to 54 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 65 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Lanai City

Today: Mostly sunny. Breezy. Highs 72 to 79. Northeast winds up to 20 mph increasing to 10 to 25 mph in the afternoon.

Tonight: Partly cloudy. Breezy. Lows around 67. Northeast winds 15 to 25 mph.

Monday: Sunny and windy. Highs 73 to 79. Northeast winds 15 to 30 mph.

Kaunakakai

Today: Mostly sunny. Breezy. Highs 71 to 85. Northeast winds 10 to 20 mph.

Tonight: Partly cloudy. Breezy. Lows 58 to 73. Northeast winds 10 to 20 mph.

Monday: Sunny and breezy. Highs 69 to 83. Northeast winds 10 to 25 mph.

Detailed Forecast

Synopsis

A weak trough will exit west of the state early this morning, however some showery conditions will linger over Kauai through the morning hours, while rather dry conditions prevail over the rest of the state. The trough will dissipate west of the islands tonight and Monday, with trade winds increasing to breezy levels by late Monday or Monday night, and continuing through late this week. A fairly typical trade wind pattern will become established in the wake of the trough, with showers favoring windward and mauka areas, particularly at night and during the early morning hours.

Discussion

Currently at the surface, a weak trough of low pressure is located over Kauai, while a ridge axis is positioned several hundred miles north of the island chain. Breezy northeasterly trade winds are present to the west of the trough, while moderate east-northeasterly trades prevail to its east. Infrared satellite imagery shows a mix of high and low clouds resulting in partly to mostly cloudy conditions across the state. Radar imagery shows scattered to numerous showers moving into windward sections of Oahu and Kauai, with much fewer showers moving into windward areas of the other islands. Main short term focus revolves around trade wind trends and rain chances during the next couple of days.
The weak trough of low pressure will continue to push slowly west today, exiting to the west of Kauai prior to daybreak this morning. Showers will be most prevalent over windward sections of Kauai this morning, with a decrease expected for the afternoon hours. Elsewhere, rather dry trade wind weather is expected today, with only a few mainly windward and mauka showers. Winds will ease following the passage of the trough, with moderate trades then prevailing statewide through the remainder of the day.
The weak trough will dampen out west of the state tonight and Monday, while a ridge of high pressure remains in place several hundred miles north of the state. This will bring a gradual increase in trade wind speeds, with breezy conditions becoming established across the entire island chain by late Monday or Monday night. Breezy conditions are then expected to hold through late in the week as high pressure remains firmly in place to the north of the state. A fairly typical trade wind pattern is expected to prevail through late this week, with showers favoring windward and mauka areas, particularly during the overnight and early morning hours.

Aviation

Trades increasing into the moderate to locally breezy category for the next several days. Low cigs and SHRA possible over windward and mauka locations with limited spillover to leeward areas. MVFR conds possible but VFR should prevail.
AIRMET Sierra is in effect for mtn obsc over Kauai, Oahu, Molokai and Maui.
AIRMET Tango is in effect for mod upper level turb for Kauai and Oahu due to a strong jet over the state. Also, there will likely be a need for AIRMET Tango for low-level turb with trades strengthening Sunday afternoon into the evening.

Marine

A high pressure ridge will remain in place north of the Hawaiian Islands this week with easterly trade winds blowing in the fresh to locally strong range lasting into next weekend.
A small medium period northwest swell will maintain small surf heights along north and west facing shores today, shifting out of the north to north northwest direction by tonight and then fading out by Tuesday. The next small long period northwest swell pulses into the region by Wednesday afternoon, peaking by Thursday morning, then decreasing from Friday onward.
Small long period south swell energy will fade today with two additional small long period background south swells moving in on Monday and Thursday night. Surf along east facing shores will remain below normal today, with increasing surf heights peaking by Wednesday as trade winds strengthen.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov