West Side

Today: Cloudy with scattered showers. Highs around 80. Northeast winds up to 15 mph. Chance of rain 40 percent.

Tonight: Cloudy. Isolated showers in the evening. Lows 67 to 74. East winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Cloudy. Isolated showers in the afternoon. Highs 77 to 82. East winds up to 10 mph shifting to the north in the afternoon. Chance of rain 20 percent.

South Side

Today: Cloudy with scattered showers. Highs around 84. North winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Cloudy. Lows 68 to 76. North winds up to 10 mph in the evening becoming light.

Wednesday: Cloudy. Isolated showers in the afternoon. Highs around 84. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

North Shore

Today: Cloudy with scattered showers. Highs around 80 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Cloudy with isolated showers. Lows around 71 near the shore to around 54 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Wednesday: Cloudy with scattered showers. Highs around 79 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Cloudy with scattered showers. Highs 80 to 85. Northeast winds up to 15 mph. Chance of rain 40 percent.

Tonight: Cloudy. Lows around 70. North winds up to 10 mph in the evening becoming light.

Wednesday: Cloudy. Isolated showers in the afternoon. Highs around 82. Northeast winds up to 10 mph. Chance of rain 20 percent.

Upcountry

Today: Cloudy with scattered showers. Highs around 61 at the visitor center to around 68 at the summit. East winds up to 10 mph. Chance of rain 40 percent.

Tonight: Cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows around 50 at the visitor center to around 46 at the summit. Southeast winds up to 10 mph. Chance of rain 40 percent.

Wednesday: Cloudy with isolated showers. Highs around 62 at the visitor center to around 69 at the summit. Light winds. Chance of rain 20 percent.

East Maui

Today: Cloudy with scattered showers. Highs around 80 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Cloudy with isolated showers. Lows around 71 near the shore to around 54 near 5000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Wednesday: Cloudy with scattered showers. Highs around 79 near the shore to around 67 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Cloudy with scattered showers. Highs 72 to 79. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 40 percent.

Tonight: Cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows around 67. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 30 percent.

Wednesday: Cloudy. Scattered showers in the afternoon. Highs 71 to 77. Light winds. Chance of rain 40 percent.

Kaunakakai

Today: Cloudy with scattered showers. Highs 69 to 84. Northeast winds up to 10 mph. Chance of rain 40 percent.

Tonight: Cloudy with isolated showers. Lows 60 to 73. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Cloudy. Isolated showers in the afternoon. Highs 67 to 83. East winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light to moderate rain continues over the western portion of the state as the main band of showers gradually drifts eastward across Maui County and the Alenuihaha Channel. Periods of showery, somewhat unstable conditions are expected to persist through much of the week. Light and variable winds may also promote localized land and sea breeze development. By the latter half of the week, a return to light east to southeast winds will bring generally quieter weather, however, shower activity could increase by the weekend as an upper-level trough approaches from the northwest.

Discussion

The main shower band has drifted eastward from the previous forecast and is now located over Maui County and the Alenuihaha Channel. Rainfall rates from these showers have been producing below a tenth of an inch per hour. The subtropical jet, currently located just north of the Hawaiian Islands and drifting southward, will help steer these intermittent shower bands over the region for the next several days. Cloud coverage will also be maintained through much of the week, ensuring dewpoints remain high in the upper-60s, leading to noticeably humid conditions. With the lighter surface winds in the forecast, initially from the southeast before becoming variable, any diurnal heating will be enough to trigger land and sea breeze activity. This may bring leeward and interior showers throughout the day, and partial clearing overnight for most of the islands. Otherwise, these weak, intermittent shower bands will persist as they ride the subtropical jet following the southwesterly flow aloft.
Toward the latter half of the week, the surface low pressure system, once anchored just north of the islands, will finally dislodge and move northeastward opening the doors for high pressure to quickly build in its place. Light trades attempt to develop in response, however, latest model guidance depicts an upper-level trough digging down into the vicinity of the state from the northwest. While not overly impressive, nor super impactful currently, it is expected to limit the strength of the trades. That being said, it is worth keeping an eye on the evolution of the upper-level trough to determine if it enhances the ongoing shower activity (especially with the lingering moisture-laden airmass across the state), or if it is simply passing through.

Aviation

Low cigs and isol SHRA will continue across the islands. MVFR conds possible but VFR should prevail. Winds will generally be driven by land-sea breezes. The forecast generally trends back toward trades tomorrow into Thursday.
No AIRMETs in effect.

Marine

A weak surface trough will reside just west of the state through Thursday. This will allow for gentle southeast flow across the waters and locally moderate easterly flow in the typical windy channels surrounding Maui and the Big Island. Surface high pressure building far north of the region will help tighten the pressure gradient and bring moderate to locally fresh easterly trades across the Hawaiian coastal waters Friday into this weekend.
A small, short-period, northwest swell will continue to slowly diminish through the rest of the week and into the weekend.
A small, medium-period, south swell has arrived at the near shore buoys and should provide a boost to surf along south facing shores through late week before gradually subsiding into the weekend.
Surf along east facing shores will remain below seasonal average with lighter than average trade winds near and upstream of the islands forecast through late this week. A slight bump up in surf may occur Friday into this weekend with the increase of easterly flow.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov