West Side

Today: Sunny and breezy. Isolated showers in the morning. Highs 78 to 83. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 69 to 75. Northeast winds 10 to 20 mph.

Tuesday: Mostly sunny. Isolated showers in the morning. Highs 78 to 83. Northeast winds up to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny. Highs around 85. Northeast winds 10 to 15 mph.

Tonight: Mostly clear. Lows 68 to 76. North winds up to 15 mph.

Tuesday: Mostly sunny. Highs around 85. North winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 79 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 73 near the shore to around 54 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 80 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Isolated showers in the morning. Highs 78 to 86. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 68 to 74. Northeast winds 10 to 15 mph decreasing to up to 15 mph after midnight.

Tuesday: Sunny and breezy. Isolated showers in the morning. Highs 79 to 86. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with scattered showers. Highs around 60 at the visitor center to around 68 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows around 48 at the visitor center to around 45 at the summit. East winds 10 to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 60 at the visitor center to around 67 at the summit. East winds up to 15 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 79 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 73 near the shore to around 54 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 80 to 86 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Lanai City

Today: Sunny. Highs 71 to 80. Northeast winds 10 to 15 mph.

Tonight: Mostly clear. Lows 65 to 70. Northeast winds 10 to 15 mph decreasing to up to 10 mph after midnight.

Tuesday: Mostly sunny. Highs 71 to 80. East winds up to 15 mph.

Kaunakakai

Today: Sunny and breezy. Highs 70 to 86. East winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Lows 59 to 75. East winds 10 to 20 mph.

Tuesday: Sunny and breezy. Highs 70 to 86. East winds 10 to 20 mph.

Detailed Forecast

Synopsis

Breezy trades will gradually weaken to moderate speeds by the latter half of the week. Periodic showers will filter in on the trade wind flow, mainly focusing over windward and mauka areas through midweek. By the weekend, the background flow may become light enough to support land and sea breeze development, and showers may increase in some leeward areas.

Discussion

An area of showers extended from Kauai County and Oahu east into the open waters this morning, and light showers have been frequent visitors to those islands. Maui County and the Big Island have been mostly dry. This pattern should continue into the daylight hours, especially over Kauai County, as satellite shows additional clouds capable of producing showers headed that way. The trade wind inversion is expected to remain around 7000 feet today, resulting in fairly stable conditions and no heavy rain is forecast.
With high pressure at the surface off to our northeast, trade winds will continue today and for several more days. The pressure gradient will begin to weaken Wednesday night into Thursday, and remain weak through the weekend, leading to lower wind speeds. This in turn will allow for a hybrid pattern of weak trade winds combined with sea and land breezes. And sea breezes during the day usually lead to an increase in afternoon clouds and showers over leeward areas. The forecast was moved farther in this direction with this latest update. Otherwise, the long range forecast calls for a return to stronger trades early next week. There are no tropical systems within range of the islands, and none expected over the next seven days (at least). Finally, models remain consistent in showing a front approaching the state from the northwest this weekend, but the moist band associated with it is not expected to reach us.

Aviation

Moderate to breezy trade winds are expected to continue through Monday before gradually weakening heading into midweek. Showers embedded within the tradewind flow are primarily impacting windward and mountain areas, with limited spillover into leeward areas. Brief MVFR conditions are expected within showers while VFR prevails elsewhere.
No AIRMETs for mountain obscuration are in effect this morning, but it is possible that with clouds and showers moving in, it could be issued for any of the islands.
AIRMET Tango is in effect for mechanical turbulence downwind of the mountains due to breezy trade winds, and this is expected to continue through at least Monday.

Marine

Surface high pressure will remain anchored far northeast of the islands through early this week. A Small Craft Advisory (SCA), remains in effect for the typical windy waters around Maui and the Big Island until 6 PM tonight. By midweek, a ridge north of the islands associated with the high will be weakened and depressed southward resulting in even weaker trades. As the ridge shifts further south, it will eventually end up near the Hawaiian Islands by Friday or Saturday, which will bring light and variable winds across the area towards the end of the week.
Small long-period south swell continue to fill in this morning. Energy from this swell is expected to peak later today into tomorrow and bump up surf to slightly higher than the June averages, but still below advisory criteria. This swell is expected to fade through midweek. A smaller pulse of south- southwest swell is due late Thursday and Friday, and a more significant south- southwest swell is on track to arrive next weekend, likely bringing advisory level surf by late Sunday along south facing shores.
The combination of a large south-southwest swell coinciding with the peak monthly tides will lead to significant wave runup across areas of the shore that typically remain dry during the afternoon high tide cycle from June 14th through June 16th. Coastal flooding is also expected across low-lying coastal roadways, docks, boat ramps and other coastal infrastructure.
Small background energy from the west-northwest is possible over the next several days from a former Typhoon in the West Pacific last week.
Rough surf along east-facing shores will remain around seasonal averages slowly declining through midweek as trades ease. Surf will drop well below seasonal levels along east facing shores by the end of the week.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov