West Side

Today: Mostly sunny with a 20 percent chance of showers. Highs 83 to 88. East winds up to 10 mph shifting to the southwest in the afternoon. Gusts up to 30 mph.

Tonight: Partly cloudy. Lows 69 to 77. Northeast winds up to 15 mph.

Tuesday: Mostly sunny. Highs 82 to 87. East winds up to 15 mph.

South Side

Today: Sunny. Highs around 91. Northwest winds up to 15 mph shifting to the southwest in the afternoon.

Tonight: Partly cloudy. Lows 71 to 77. North winds up to 15 mph.

Tuesday: Mostly sunny. Breezy. Highs around 90. Northeast winds up to 15 mph shifting to the north up to 25 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with a 50 percent chance of showers. Highs 81 to 88 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Tonight: Breezy. Mostly cloudy with a 40 percent chance of showers. Lows around 73 near the shore to around 55 near 5000 feet. East winds up to 20 mph.

Tuesday: Partly sunny in the morning then becoming mostly sunny. Breezy. A 20 percent chance of showers. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Central Maui

Today: Sunny and breezy. A 20 percent chance of showers in the morning. Highs 84 to 92. East winds up to 20 mph.

Tonight: Partly cloudy. Breezy. Lows 70 to 75. East winds 10 to 20 mph shifting to the northeast after midnight.

Tuesday: Mostly sunny. Breezy. Highs 83 to 90. Northeast winds up to 20 mph increasing to 10 to 25 mph in the afternoon.

Upcountry

Today: Partly sunny with chance of showers in the morning, then mostly sunny with slight chance of showers in the afternoon. Highs around 67 at the visitor center to around 69 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with a 20 percent chance of showers. Lows around 53 at the visitor center to around 50 at the summit. East winds up to 15 mph.

Tuesday: Breezy. Mostly sunny with a 20 percent chance of showers. Highs around 69 at the visitor center to around 63 at the summit. East winds up to 20 mph.

East Maui

Today: Breezy. Partly sunny with a 50 percent chance of showers. Highs 81 to 88 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Tonight: Breezy. Mostly cloudy with a 40 percent chance of showers. Lows around 73 near the shore to around 55 near 5000 feet. East winds up to 20 mph.

Tuesday: Partly sunny in the morning then becoming mostly sunny. Breezy. A 20 percent chance of showers. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Lanai City

Today: Mostly sunny with a 20 percent chance of showers. Highs 76 to 84. North winds up to 10 mph shifting to the west in the afternoon.

Tonight: Partly cloudy. A 20 percent chance of showers in the evening. Lows around 69. Northeast winds up to 15 mph.

Tuesday: Mostly sunny. Breezy. Highs 76 to 83. Northeast winds up to 20 mph.

Kaunakakai

Today: Mostly sunny. Breezy. A 20 percent chance of showers in the morning. Highs 76 to 91. East winds up to 20 mph.

Tonight: Partly cloudy. Lows 62 to 76. East winds up to 15 mph.

Tuesday: Mostly sunny. Highs 75 to 91. East winds up to 15 mph.

Detailed Forecast

Synopsis

Breezy trade winds will gradually return today as weak trough moves west of the state tonight. Isolated to scattered clouds and showers will persist through the morning hours mainly along windward and mauka regions with few showers spilling over the leeward areas at times. A gradual drying trend is expected tonight into Tuesday with typical summer time trade wind weather (stable and mostly dry conditions) expected during the second half of week.

Discussion

A weak surface trough associated with the remnants of former Tropical Cyclone Ivo will continue to move west over the state today, allowing trade wind speeds to increase throughout the day. This morning sounding from Lihue shows tradewind inversion height around 9 kft with precipitable water vapor values around 1.68 inches. Scattered, light to moderate showers can be seen on the radar early this morning, mainly focused over windward and mountain areas with some showers spilling over to leeward areas at times. Expect showers to ease slightly during the day as drier air filters in from the east, expect for the Kona slopes of the Big Island, which will see some clouds and shower development this afternoon as seabreezes develop.
As this trough exits the area tonight, we should see less clouds and drier conditions on Tuesday. Trade winds will continue to strengthen Tuesday afternoon with moderate to locally breezy trades expected throughout the rest of the week. Typical summer time trade wind weather is expected throughout the second half of the week with stable and mostly dry conditions. Subtle increases of moisture will bring in some windward showers at times with mostly dry conditions persisting over leeward areas. Trade winds could slightly strengthen over next weekend.

Aviation

Moderate to locally breezy trades will persist through the forecast period. Low cigs and SHRA will continue over windward and mauka areas through the early morning hours generating MVFR conds in SHRA, otherwise VFR prevails.
AIRMET Sierra has been issued for MTN OBSC overnight due to an increase in low clouds and SHRA along windward and mauka regions. Conds may become VFR during the afternoon hours has inversion heights increase and SHRA decrease.
AIRMET Tango may be needed later today as wind speeds increase below the inversion.

Marine

Fresh to locally strong trades will persist through the week as ridging stays situated north of the state. The Small Craft Advisory (SCA), for the typical windy waters around Maui and the Big Island, will remain in effect through at least Wednesday morning with a likely extension into the weekend.
The ongoing small, medium period south (180-190) swell will hold through tomorrow and generate waist to near head high surf within higher sets. A slightly larger, medium to long period, south swell is progged to arrive on Wednesday, adding a little bump to surf heights along south facing shores through the remainder of the work week.
Choppy conditions will continue for east-facing shores through the forecast period due to the persistent fresh trades. Meanwhile, expect surf to be flat to tiny along north facing shores.

Fire weather

Conditions should remain below critical fire weather thresholds through the first half of this week. A weak low-level trough will continue to move across the state today, bringing an increase in humidity and shower activity and weakening the trade wind inversion. 12Z sounding from Lihue shows the trade wind inversion has lifted from 5000 feet Sunday afternoon to 9000 feet early this morning. As the trough exits the area, we should see the return of stable and dry conditions by Tuesday afternoon. During the second half of the week we should see stable and dry conditions with a stronger trade wind inversion at around 5000-6000 ft. Breezy trades are also expected during this time, which could produce elevated fire weather concerns later in the week through next weekend.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov