West Side

Today: Mostly sunny with isolated showers. Highs around 83. Light winds becoming southeast up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 69 to 76. East winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs 80 to 86. East winds up to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny. Isolated showers in the afternoon. Highs around 88. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 69 to 77. Light winds becoming north up to 10 mph after midnight.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 88. North winds up to 15 mph. Chance of rain 20 percent.

North Shore

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 81 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 72 near the shore to around 53 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Partly sunny with scattered showers. Highs around 83 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Mostly sunny. Isolated showers in the afternoon. Highs 82 to 89. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 68 to 74. East winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs 82 to 89. Northeast winds up to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with isolated showers. Highs around 61 at the visitor center to around 66 at the summit. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Scattered showers in the evening. Lows around 49 at the visitor center to around 44 at the summit. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 30 percent.

Tuesday: Sunny with isolated showers. Highs around 62 at the visitor center to around 65 at the summit. East winds up to 10 mph. Chance of rain 20 percent.

East Maui

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 81 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 72 near the shore to around 53 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Partly sunny with scattered showers. Highs around 83 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 81. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 30 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 64 to 69. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Tuesday: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 82. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 30 percent.

Kaunakakai

Today: Mostly sunny. Isolated showers in the afternoon. Highs 74 to 89. Light winds becoming east up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows 60 to 75. East winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers. Highs 74 to 89. East winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

An upper-level low centered several hundred miles north of the state will continue to move south through midweek, then weaken and slide off to the west. This will bring a chance for heavier showers and a few thunderstorms from Wednesday into Friday evening. Relatively light southeast surface winds continue through Tuesday, with stronger trades kicking in Wednesday into lasting into next weekend.

Discussion

Currently we have some isolated showers moving across the islands. A few low clouds are hanging around where there are showers with some upper level clouds associated with a jet that is moving out of the area. Expect winds to remain light today.
A strong upper level low will continue to move south through Wednesday afternoon, reaching the western end of the state (roughly centered overhead) before moving to the west and weakening late this week and into the weekend. This will bring cooler air aloft, increase instability and the chance for stronger showers and a few thunderstorms. With confidence increasing thunderstorms have been introduced into the forecast. The most likely area is the western part of the state, but we can't rule out storms in the east at this time.
The other significant change this coming week will be the surface winds. Relatively light southeast winds will give way to easterly trades Wednesday. Wind speeds will increase, especially in the usual windy areas.

Aviation

Another day of light winds and daytime sea breezes is expected today. Low cigs and a few SHRA can be expected across leeward and interior locations. MVFR conds possible but VFR will prevail.
No AIRMETs in effect.

Marine

A trough will linger north of Hawaii resulting in light east to southeast winds across the state. The trough will fade while high pressure builds far to the northeast Tuesday night with trade winds building in for the rest of the week. An upper low will also track over the islands beginning around Tuesday night resulting in possible thunderstorms Wednesday through Friday.
A long period northwest swell has arrived and will peak tonight. A High Surf Advisory is now posted for north and west facing shores of Niihau, Kauai, Oahu, Molokai and north facing shores of Maui through Tuesday. Surf will drop off Tuesday night through Thursday.
Small, medium period south swell will continue through the week with minor pulses of longer periods arrive tonight and again on Saturday. East shores will remain small due to light winds, but should begin to increase beginning Wednesday as trades strengthen.
There may be some minor flooding within low laying areas during high tide this morning.

Fire weather

Light winds and isolated to scattered showers will help maintain fire weather below critical thresholds for the next several days. Inversion heights will range from 6,000 to 7,000 feet.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Tuesday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.

Data Courtesy of NOAA.gov