West Side

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 83. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with scattered showers. Lows 62 to 72. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 72 to 83. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

South Side

Today: Mostly sunny. Highs 70 to 84. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

Tonight: Mostly clear. Isolated showers after midnight. Lows 60 to 71. North winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Highs 69 to 83. Northeast winds 10 to 20 mph.

North Shore

Today: Mostly cloudy. Breezy. Occasional showers in the morning, then scattered showers in the afternoon. Highs 65 to 83. East winds 10 to 20 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers after midnight. Lows 53 to 75. East winds up to 15 mph. Chance of rain 90 percent.

Wednesday: Mostly cloudy. Showers in the morning, then scattered showers in the afternoon. Highs 64 to 82. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 80 percent.

Central Maui

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs 78 to 84. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 65 to 70. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs 77 to 82. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 50 to 69. Northeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows around 44 at the visitor center to around 41 at the summit. Northeast winds up to 10 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 50 to 69. Northeast winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Mostly cloudy. Breezy. Occasional showers in the morning, then scattered showers in the afternoon. Highs 65 to 83. East winds 10 to 20 mph. Chance of rain 90 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then showers after midnight. Lows 53 to 75. East winds up to 15 mph. Chance of rain 90 percent.

Wednesday: Mostly cloudy. Showers in the morning, then scattered showers in the afternoon. Highs 64 to 82. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 80 percent.

Lanai City

Today: Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 69 to 79. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming mostly clear. Lows 59 to 66. Northeast winds 10 to 15 mph.

Wednesday: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 67 to 78. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaunakakai

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 68 to 84. East winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 55 to 72. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Breezy. Isolated showers. Highs 67 to 84. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate easterly trade winds will continue into early next week. An upper level trough approaching the islands and will deepen into an upper low just north of Kauai today. This upper disturbance will pass slowly through the region and then linger northeast of the state into the weekend. Expect periods of enhanced clouds and showers across the region through the week. Shower activity will favor windward mountain areas in the overnight to early morning hours, with brief periods of showers drifting into leeward areas. Locations sheltered from the moderate easterly trade winds could also see increased clouds and a few showers during the afternoons.

Discussion

The water vapor satellite imagery channel shows the upper level trough moving into the western islands this morning continues to deepen into an upper level low forecast to track slowly eastward through the island chain. This upper low will lift subsidence temperature inversion heights and enhance clouds and showers across the state. Windward mountains will see the highest shower activity during the overnight to early morning hours, while terrain sheltered leeward western mountains will see sea breeze trade wind convergence zones triggering enhanced showers during the afternoon hours each day.
The upper low and trailing upper trough will slow down and remain just northeast of the Hawaiian Islands into the weekend. The upper level lift just upstream of the islands will keep inversion and cloud heights elevated, allowing periods of showers to continue through the week. Only subtle day to day changes in island weather patterns are expected. This wet trade wind pattern may linger into the first half of next week as a shallow cold front and upper level trough approach the islands from the northwest. The wet season continues into the first week of May.

Aviation

Moderate to locally breezy trade winds will continue during the next couple of days. Scattered to numerous shower activity can be expected over the next 24 hours or so across windward and mountain areas as an upper level trough moves across the region. AIRMET Sierra is currently in effect for windward areas across the state due to degraded cigs under showers, however this is expected to improve during the day today.

Marine

Moderate to fresh east-northeast trades will continue today before strengthening late tonight into tomorrow as a weak trough shifts to the west and a ridge builds north of the state. This will likely correspond to Small Craft Advisory winds across the typically windier waters surrounding Maui County and the Big Island beginning Wednesday.
A small bump in surf is expected today with the arrival of a small northwest swell. An upward trend is expected during the second half of the week as another northwest swell arrives. Looking further ahead, a storm- force low east of Japan will send a moderate, longer-period northwest swell toward the islands for Friday and Saturday, with surf heights potentially approaching advisory levels along exposed north and west facing shores.
Surf along south-facing shores will remain small through much of the week, with mainly background south to southwest swell expected. Another south-southwest pulse may arrive by this weekend from recent activity within our swell window east of New Zealand, providing a small increase in surf.
Surf along east-facing shores will remain relatively small and choppy through midweek, with a slight rise possible later in the week as trades strengthen.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov