West Side

Rest Of Today: Partly cloudy with isolated showers. Highs 81 to 86. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 70 to 77. Light winds becoming northeast up to 10 mph after midnight. Chance of rain 20 percent.

Labor Day: Sunny. Highs 82 to 87. East winds up to 15 mph.

South Side

Rest Of Today: Mostly clear. Highs around 89. Light winds becoming north up to 10 mph in the morning, then shifting to the west around 10 mph in the afternoon.

Tonight: Mostly clear. Lows 71 to 78. Northwest winds up to 10 mph.

Labor Day: Sunny. Highs around 89. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

North Shore

Rest Of Today: Mostly cloudy. Scattered showers early in the morning, then numerous showers in the afternoon. Highs 80 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Partly cloudy with isolated showers. Lows around 73 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Labor Day: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Central Maui

Rest Of Today: Mostly sunny early in the morning then becoming sunny. Highs 84 to 91. Light winds becoming northeast up to 15 mph.

Tonight: Mostly clear. Lows around 72. Northeast winds up to 10 mph.

Labor Day: Sunny. Highs 83 to 90. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

Upcountry

Rest Of Today: Mostly cloudy. Scattered showers early in the morning, then numerous showers in the afternoon. Highs around 64 at the visitor center to around 69 at the summit. Light winds. Chance of rain 70 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 52 at the visitor center to around 48 at the summit. Light winds. Chance of rain 20 percent.

Labor Day: Sunny. Isolated showers in the afternoon. Highs around 66 at the visitor center to around 71 at the summit. Light winds. Chance of rain 20 percent.

East Maui

Rest Of Today: Mostly cloudy. Scattered showers early in the morning, then numerous showers in the afternoon. Highs 80 to 86 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tonight: Partly cloudy with isolated showers. Lows around 73 near the shore to around 54 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 20 percent.

Labor Day: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Lanai City

Rest Of Today: Sunny early in the morning then becoming mostly sunny. Isolated showers in the afternoon. Highs 75 to 82. Light winds. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then mostly clear after midnight. Lows around 68. Light winds becoming northeast up to 10 mph after midnight. Chance of rain 20 percent.

Labor Day: Sunny. Isolated showers in the afternoon. Highs 75 to 83. Northeast winds up to 15 mph. Chance of rain 20 percent.

Kaunakakai

Rest Of Today: Sunny early in the morning then becoming mostly sunny. Scattered showers in the afternoon. Highs 75 to 90. Light winds becoming east up to 10 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 62 to 76. Light winds becoming northeast up to 10 mph after midnight. Chance of rain 20 percent.

Labor Day: Sunny. Highs 75 to 91. East winds 10 to 15 mph.

Detailed Forecast

Synopsis

Moderate trades will continue through the week, with localized land and sea breezes at times. Mostly dry and stable conditions will prevail, with the exception of a brief uptick in shower activity today through Monday.

Discussion

High pressure far northeast of Hawaii remains displaced and weakened by a large area of low pressure. This synoptic setup will maintain moderate trades through most of the forecast period, with diurnal sea and land breezes developing across the state, particularly in leeward and interior areas.
CIMSS MIMIC Precipitable Water satellite imagery shows a band of tropical moisture moving up the island chain this morning as a weak low tracks westward south of state. As this deeper tropical moisture works its way across the state, it will help to enhance the diurnal convective pattern, with increased shower activity expected along sea breeze convergence zones, particularly over the western slopes of the eastern islands today followed by activity focused mainly over Oahu and Kauai tonight into Monday as moisture begins to exit stage left. Weak cyclonic flow aloft courtesy of a nearly stationary upper level low just northwest of the state will weaken the inversion slightly over Oahu and Kauai giving showers a boost in intensity, particularly over interior and leeward Kauai, but organized heavy rainfall is not anticipated. Mugginess will also be on the rise during this time as dewpoints creep into the low 70s no later than Monday and persisting into Tuesday.
Conditions should return to a more typical stable hybrid trade wind and land-sea breeze pattern Tuesday onward, as strong capping builds beneath the mid-level ridge and the surface ridge remains seasonably weak.

Aviation

Light to moderate trade winds will prevail through tomorrow, allowing for sea breeze development by this afternoon, bringing clouds and showers to some leeward and interior areas. Deeper moisture moving up the island chain from the southeast to northwest today through tomorrow and some weak instability aloft may allow for these showers to become a little more active during this period, with MVFR conditions focused mainly over windward areas during the overnight and early morning periods and over island interiors and leeward areas each afternoon. VFR should prevail elsewhere.
AIRMET Sierra for mountain obscuration is in effect for windward portions of the Big Island this morning. While conditions are expected to improve for this area later today, AIRMET Sierra may be needed for other portions of the island chain as showers develop.

Marine

A ridge of high pressure north of the state will gradually shift further south in response to a developing low far north of the state. As the ridge meanders closer to the islands our trade wind speeds will decrease, with gentle to moderate trades expected through early next week. Winds should be light enough for localized sea breezes, especially across leeward waters.
Surf along south facing shores is expected to steadily decline through Monday as the swell fades, returning to background levels early in the week.
Surf along north facing shores will see a small, short-period swell arriving tomorrow. This swell will be overshadowed by longer period energy out of the northwest starting Monday night, peaking on Tuesday. Another reinforcing pulse out of the north should arrive around the same time the northwest swell arrives. A mix of north and northwest swells are expected Tuesday through Thursday.
Below average surf is expected to continue along east facing shores persisting through early next week.
Peak monthly high tides, combined with water levels running higher than predicted, may lead to minor flooding along the shoreline and in low-lying coastal areas toward the end of the week. Coastal flooding may be possible around the daily afternoon peak tide.

Fire weather

Winds remain on the lighter side as moderate trades prevail through the forecast period. Sea level dewpoints creep into the upper 60s and lower 70s no later than Monday and continue into Tuesday ensuring relative humidity values remain elevated during this time. Drier conditions return mid-week onward.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov