West Side

Today: Mostly sunny. Breezy. Highs 79 to 86. Northeast winds 10 to 25 mph.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 68 to 75. Northeast winds up to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Scattered showers in the morning. Highs 80 to 86. East winds up to 20 mph. Chance of rain 40 percent.

South Side

Today: Mostly sunny. Breezy. Highs around 88. Northeast winds 10 to 25 mph.

Tonight: Mostly clear. Breezy. Lows 65 to 76. North winds up to 20 mph.

Monday: Mostly sunny. Highs around 88. North winds up to 15 mph shifting to the northeast in the afternoon.

North Shore

Today: Mostly cloudy. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 82 near the shore to around 65 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 70 near the shore to around 51 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Breezy. Showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Central Maui

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Highs 81 to 88. Northeast winds 10 to 25 mph.

Tonight: Breezy. Partly cloudy in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 71. Northeast winds 10 to 20 mph shifting to the east after midnight. Chance of rain 40 percent.

Monday: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 81 to 88. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny in the morning then becoming partly sunny. Highs around 63 at the visitor center to around 74 at the summit. Northeast winds up to 10 mph.

Tonight: Partly cloudy. Scattered showers after midnight. Lows around 45 at the visitor center to around 50 at the summit. East winds up to 10 mph. Chance of rain 50 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 63 at the visitor center to around 70 at the summit. East winds up to 10 mph. Chance of rain 50 percent.

East Maui

Today: Mostly cloudy. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 82 near the shore to around 65 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 70 near the shore to around 51 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Breezy. Showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 80 percent.

Lanai City

Today: Sunny in the morning then becoming mostly cloudy. Breezy. Highs 73 to 82. Northeast winds 15 to 25 mph.

Tonight: Breezy. Mostly cloudy with isolated showers in the evening, then mostly clear after midnight. Lows around 66. Northeast winds 10 to 25 mph decreasing to up to 20 mph after midnight. Chance of rain 20 percent.

Monday: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 73 to 82. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Kaunakakai

Today: Mostly sunny in the morning then becoming partly sunny. Breezy. Highs 70 to 88. Northeast winds 10 to 20 mph.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 58 to 75. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Monday: Breezy. Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 70 to 89. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate to locally breezy trades will persist through much of the week as high pressure remains anchored north of the state. A dry and stable air mass will keep windward showers sparse and leeward areas mostly dry. Trades may ease briefly late this week before strengthening again next weekend as high pressure rebuilds to the north. Tropical systems far east of the state will be monitored, but pose no immediate impacts to the islands.

Discussion

Broad surface high anchored well north of the Hawaiian Islands remains the dominate synoptic feature through much if the forecast period. This pattern will support moderate the locally breezy trades through the next several days. Trades are expected to ease slightly late this week as the surface high weakens and shifts northeastward, though this lull should be brief. Guidance continues to indicate the high will rebuild and strengthen during the latter half of the forecast period, allowing trades to increase once again.
Despite the persistent trade wind regime, typical embedded trade showers will remain limited as a notably dry air mass persists across the state. Water vapor imagery continues to depict widespread low- to mid-level dry air, and forecast precipitable water values remain around 1 to 2 standard deviations below climatological normals through much of the upcoming week. However, some model guidance is hinting at a modest uptick of moisture Tuesday into Wednesday of next week, but total accumulation is expected to still be sparse. Overall, rainfall will generally favor isolated, light windward and mauka showers, with leeward areas remaining predominately dry.
Forecast confidence beyond the middle of the next week becomes increasingly dependent on the evolution of the tropical disturbances currently located well east of the Central Pacific near the Mexican coast. While deterministic and ensemble guidance suggests some westward progression, it remains far too early to determine whether any of these systems or their associated moisture will influence the Hawaiian Islands. At this time, no changes to the sensible weather forecast are warranted, though these tropical features will continue to be monitored closely over the coming days as forecast confidence increases.

Aviation

Moderate trades will continue through the forecast period. Clouds and isolated to scattered showers will remain over windward and mauka locations. Conditions will be VFR apart from isolated MVFR over windward and mauka areas in clouds and showers.
No AIRMETs are in effect.

Marine

Fresh to locally strong trades will continue today, and a Small Craft Advisory (SCA) remains in effect for the typically windy waters around Maui and the Big Island through 6 pm. The trades will ease tonight and Monday as high pressure north of the islands weakens, with the trades then holding at moderate speeds through Tuesday. The trades will restrengthen back to fresh and locally strong speeds Wednesday and Thursday as high pressure strengthens north of the island chain.
Surf along south facing shores will remain a bit below the summertime average today. A larger, south swell is expected to build late today and tonight, then peak around the advisory level Monday into early Wednesday. A High Surf Advisory will likely be required for south facing shores of all islands later today or tonight. As this swell slowly fades during the middle of the week, a new long period south swell will arrive on Thursday, keeping surf elevated through next weekend.
Surf along north-facing shores will remain at flat to tiny levels through next weekend.
Surf along east facing shores will remain close to seasonal levels today, then lower slightly Monday through Wednesday as the trades ease upstream of the islands. East shore surf should then build back close to seasonal levels late in the week through next weekend. Additionally, swell from Tropical Storm Elida may give a slight boost to east shore surf during the middle of the week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov