Photo Credit: Tyler Rooke

West Side

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 90. Northeast winds 15 to 25 mph. Chance of rain 50 percent.

Tonight: Mostly clear. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows 68 to 75. East winds 10 to 25 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 89. East winds 10 to 20 mph. Chance of rain 40 percent.

South Side

Today: Sunny and breezy. Isolated showers in the morning. Highs around 88. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 68 to 74. Northeast winds up to 20 mph.

Tuesday: Sunny. Highs around 88. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 76 to 84 near the shore to around 67 near 5000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with showers likely. Lows around 71 near the shore to around 52 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 70 percent.

Tuesday: Breezy. Partly sunny with scattered showers. Highs 77 to 84 near the shore to around 67 near 5000 feet. Southeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Central Maui

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 80 to 88. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 68 to 73. East winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 81 to 89. East winds 10 to 25 mph. Chance of rain 20 percent.

Upcountry

Today: Breezy. Mostly sunny with scattered showers. Highs around 63 at the visitor center to around 60 at the summit. East winds up to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows around 49 at the visitor center to around 45 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Tuesday: Breezy. Mostly sunny with scattered showers. Highs around 63 at the visitor center to around 60 at the summit. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 76 to 84 near the shore to around 67 near 5000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with showers likely. Lows around 71 near the shore to around 52 near 5000 feet. Southeast winds up to 20 mph. Chance of rain 70 percent.

Tuesday: Breezy. Partly sunny with scattered showers. Highs 77 to 84 near the shore to around 67 near 5000 feet. Southeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Lanai City

Today: Sunny and breezy. Isolated showers in the afternoon. Highs 74 to 82. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 63 to 68. Northeast winds 10 to 20 mph.

Tuesday: Sunny. Isolated showers in the afternoon. Highs 73 to 82. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Kaunakakai

Today: Sunny and breezy. Isolated showers in the morning. Highs 70 to 89. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly clear with isolated showers. Lows 58 to 74. East winds 10 to 20 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 70 to 90. East winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Breezy to locally strong trades will focus cloud and showers over windward and mauka areas through Tuesday. The arrival of remnant moisture from a decaying tropical low will favor an increase in showers late Tuesday night through early Thursday morning.

Discussion

Greater stability compared to recent days is evident on the latest soundings out of Lihue and Hilo, a consequence of building mid- level ridging and dry advection centered around 700mb. This is contributing to decreased shower coverage and intensity over the forecast area this morning. Little change in expected through the near term as mid-level ridging and dry air aloft hold firm, reinforcing existing stability through Tuesday. Locally strong trades will ease just slightly during this time and will allow the wind advisory to expire on schedule with the morning forecast package.
Attention then turns to the remnant tropical circulation, currently approaching 140W, and its attendant moisture field which expands well westward to around 145W. As the circulation transitions to a a shallow open wave the associated moisture field will tend to become increasingly elongated and more aligned with the prevailing trade winds. This results in some lead moisture potentially grazing the windward zones as early as Tuesday evening which would result in an increase in shower coverage mainly over the typical windward and mauka zones. Otherwise, model consensus remains in tact that the weakening surface trough and deepest will reach the eastern end of the state during the predawn hours Wednesday. Forecast soundings indicate saturation through about 10-12kft which will allow widespread showers to develop over all windward zones Wednesday and persist through Wednesday night. Low stability within this layer will favor frequent moderate showers while strengthening trades encourage frequent leeward drift of showers quite possibly persisting through the typically- unfavorable daytime hours on Wednesday. Nonetheless, the hostile mid-level environment, lack of convective instability, and the relatively shallow nature of the incoming moisture field will ultimately limit heavy rainfall potential. One potential exception will be Leeward Big Island where diurnal convection may capitalize on the rich low-level moisture field once it becomes established on the lee side of the island no later than Thursday afternoon. Even then, however, the column will be too warm/stable to support thunder and extensive cloud cover may further limit destabilization there. The trailing subsidence wake as the trough departs westward early Thursday will favor a drying trend through the day.
Global models have trended away from their depiction of deepening upper trough over the islands this weekend, instead tending to position it west of the forecast area. This has contributed to decreased spread among the solutions regarding the track Darby and its eventual remnant moisture field which is now modeled to arrive on former-Bonnie's heels this weekend. This would bring another round of widespread rainfall, mainly focused over windward and mauka zones. With that said, evolution of the aforementioned upper trough has been a source of uncertainty in the extended range and caution will be exercised as this time period enters the medium range. No changes made from day 5 onward at this time.

Aviation

A high pressure system far north of the Hawaiian islands will continue to produce moderate to breezy winds today. Passing showers along windward and mountain slopes will continue to produce brief periods of MVFR conditions over windward airfields. More isolated shower coverage may develop over leeward areas.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of all island mountains. This AIRMET will likely continue through Tuesday.

Marine

Fresh to strong easterly trades will continue through Tuesday, then potentially increase to strong levels for most waters Tuesday night through midweek as remnants of former Hurricane Bonnie move through. Seas will respond and become rough through this midweek period, especially south of the Big Island and through the windier channels if this scenario evolves. Although the trades may trend back to fresh to strong levels Thursday through Friday, the potential for another round of strong winds and rough seas will become a possibility over the weekend as remnants of Hurricane Darby move through.
Surf along south facing shores will trend up this week as overlapping southerly pulses move through from an ongoing active pattern within Hawaii's swell window near New Zealand. Nearshore PacIOOS and offshore NDBC buoys to the south reflect a small, long-period, south-southwest pulse moving through this morning, which has increased slightly overnight (51002 currently running around 2 ft within the 13-17 sec band…buoy 51004 southeast of the Big Island up to 3.5 feet). The next pulse should begin to fill in through the day Tuesday, then peak through midweek. The largest surf is expected this weekend, with heights likely topping out above the advisory level. Recent altimeter pass Sunday showed seas within the fetch focused at the islands topping out around 45 ft…one reading of 49 ft).
Surf along east facing shores will remain rough through the week, especially as the winds potentially ramp up through the midweek period and this weekend as the aforementioned tropical remnants move through the region.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 AM HST Monday for Kahoolawe, Maui Windward West, Kohala, Big Island Interior, Big Island North.
Small Craft Advisory until 6 PM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Small Craft Advisory until 6 AM HST Monday for Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters.

Maui Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov