West Side

Rest Of Tonight: Mostly cloudy late in the evening then becoming partly cloudy. Scattered showers. Lows 65 to 72. East winds up to 10 mph. Chance of rain 50 percent.

Sunday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 79. East winds up to 15 mph. Chance of rain 30 percent.

Sunday Night: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 65 to 72. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

South Side

Rest Of Tonight: Mostly cloudy late in the evening then becoming partly cloudy. Scattered showers late in the evening, then isolated showers after midnight. Lows 64 to 74. Light winds. Chance of rain 40 percent.

Sunday: Mostly sunny with isolated showers. Highs around 85. Light winds becoming north up to 15 mph in the afternoon. Chance of rain 20 percent.

Sunday Night: Partly cloudy with isolated showers. Lows 64 to 73. North winds 10 to 15 mph. Chance of rain 20 percent.

North Shore

Rest Of Tonight: Mostly cloudy with scattered showers. Lows around 68 near the shore to around 50 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Partly sunny with scattered showers. Highs 77 to 82 near the shore to around 65 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Sunday Night: Mostly cloudy with scattered showers. Lows around 68 near the shore to around 49 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Central Maui

Rest Of Tonight: Mostly cloudy late in the evening then becoming partly cloudy. Scattered showers late in the evening, then isolated showers after midnight. Lows around 66. East winds up to 10 mph. Chance of rain 40 percent.

Sunday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 79 to 86. Northeast winds up to 15 mph. Chance of rain 30 percent.

Sunday Night: Partly cloudy with isolated showers. Lows around 66. Northeast winds around 10 mph. Chance of rain 20 percent.

Upcountry

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

Sunday: Partly sunny with scattered showers. Highs around 59 at the visitor center to around 62 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Sunday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 44 at the visitor center to around 40 at the summit. East winds around 10 mph. Chance of rain 50 percent.

East Maui

Rest Of Tonight: Mostly cloudy with scattered showers. Lows around 68 near the shore to around 50 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Partly sunny with scattered showers. Highs 77 to 82 near the shore to around 65 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Sunday Night: Mostly cloudy with scattered showers. Lows around 68 near the shore to around 49 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Lanai City

Rest Of Tonight: Mostly cloudy with scattered showers late in the evening, then partly cloudy with isolated showers after midnight. Lows 61 to 66. Northeast winds up to 10 mph late in the evening becoming light. Chance of rain 50 percent.

Sunday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 71 to 79. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 30 percent.

Sunday Night: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 61 to 66. Northeast winds around 10 mph. Chance of rain 30 percent.

Kaunakakai

Rest Of Tonight: Mostly cloudy with scattered showers late in the evening, then partly cloudy with isolated showers after midnight. Lows 56 to 72. East winds 10 to 15 mph. Chance of rain 50 percent.

Sunday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 68 to 86. East winds 10 to 15 mph. Chance of rain 40 percent.

Sunday Night: Partly cloudy with isolated showers. Lows 55 to 71. East winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Trades have returned but will occasionally become weak enough to allow localized land and sea breezes to be the dominant wind. Moderate trades around the islands will continue through Monday, as thicker clouds and greater shower frequency favors windward exposures and mauka slopes. A storm low will drop down northwest of the state through the middle of next week. This will again disrupt trade flow and introduce higher chances for island-wide rain and potential storms.

Discussion

Widely scattered showers pepper the islands this evening with the greatest concentration of rain within downstream island plumes. While moderate trades have returned to the islands, more sheltered leeward locations exhibited weak enough winds to allow afternoon warming to initiate and blossom deeper cumulus. These clouds quickly produced an inch of rain (or slightly more) over such areas as southern upcountry Maui in the Kula area between Kihei and Keokea. Greater than inch amounts also occurred today around the Puu Mali peak outside of Waimea on north Big Island just south of the Kohala Mountains. Elsewhere, most windward communities picked up a few drops but most of the day remained dry as the majority of the shower activity remained offshore. A large surface high centered far northeast of the state will continue to create a tight enough downstream pressure gradient to produce a couple of days of moderate trades. The islands still lie within a diffuse upper level trough that will eventually wash out to the northeast by Monday morning. The regional atmosphere still remains marginally unstable and moist enough to support widely scattered showers both Easter Sunday and Monday. More organized cells will occasionally hang together across the higher terrain and make it into leeward areas. There still remains an outside chance of localized flooding into tomorrow from cells that stubbornly root themselves over more windward-facing (typically mauka) slopes. Generally, the island weather forecast calls for very similar weather as experienced today.
The next weather maker will come in the form of a closed-off upper low that will sink down along and near 170W longitude and come within 600 miles northwest of Kauai. The west northwest positioning of this low will pull up more moisture-rich air over the state from the southwest. As heights begin to lower and mid to upper layers cool from the west, enhanced instability within this moistened air mass will likely induce another round or three of widespread showers and thunderstorms. With the approach of either a broad open wave trough or a closed low northwest of the islands next week, the highest rain probabilities (or areas to receive more frequent rain episodes) will be across the western half of the state. Flooding concerns may be re-awakened next Tuesday through Thursday as locally heavy precipitation falls upon saturated soils.

Aviation

Moderate trades have returned and will persist through tomorrow, ushering clouds and showers into windward and mauka areas. However, winds will be light enough to support isolated sea/land breeze development that will bring additional clouds and showers to some leeward and interior areas during the afternoon hours and clearing of these areas overnight. MVFR conditions will be possible in any showers, otherwise VFR conditions should prevail.
No AIRMETs are currently in effect.

Marine

Gentle to moderate trades will continue through Monday, then veer southeasterly in advance of a deep low that will develop NW of the islands. Winds further veer southerly Tuesday into Wednesday and then hold steady where they will remain for the remainder of the week. There will be a chance of thunderstorms during this time, particularly over the western waters.
A moderate, medium period N swell will gradually trend down through Sunday producing below average surf along N facing shores. A tiny, long period NW swell will fill in Monday into Tuesday before subsiding Wednesday which will prevent surf from going flat. In the long range, guidance depicts a gale forming Monday near the Kurils then tracking northeast to the western Aleutians by Wednesday. In this scenario, Hawaii would experience an uptick in the NW swell next weekend.
Surf along E facing shores will remain small through the weekend. E shore surf could become tiny by mid week as southerly winds emerge.
A tiny, long period S swell will move through this weekend providing a small boost in surf along S facing shores. A larger, long period SSW swell will fill in Monday into Tuesday and produce near to above average surf along S facing shores by mid week before slowly subsiding through the rest of next week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov