Photo Credit: Tyler Rooke

West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 80 to 87. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 69. East winds 10 to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Isolated showers in the morning. Highs 80 to 87. East winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs 84 to 89. Northeast winds 10 to 20 mph.

Tonight: Mostly clear. Lows around 68. Northeast winds 10 to 15 mph.

Monday: Sunny. Highs 84 to 89. Northeast winds 10 to 15 mph.

North Shore

Today: Breezy. Mostly cloudy with numerous showers. Highs 79 to 85 near the shore to 59 to 64 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows 64 to 71 near the shore to around 51 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Monday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 79 to 85 near the shore to around 66 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Central Maui

Today: Sunny and breezy. Highs around 87. Northeast winds 10 to 25 mph.

Tonight: Partly cloudy with isolated showers. Lows 66 to 72. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Isolated showers in the morning. Highs around 87. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Breezy. Mostly sunny with numerous showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 58 at the visitor center to around 54 at the summit. East winds up to 20 mph becoming 10 to 15 mph in the afternoon. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 45 at the visitor center to around 41 at the summit. East winds 10 to 20 mph. Chance of rain 50 percent.

Monday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs around 63 at the visitor center to around 60 at the summit. East winds 10 to 20 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Mostly cloudy with numerous showers. Highs 79 to 85 near the shore to 59 to 64 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows 64 to 71 near the shore to around 51 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Monday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 79 to 85 near the shore to around 66 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Lanai City

Today: Sunny and breezy. Highs 71 to 80. Northeast winds 10 to 25 mph.

Tonight: Partly cloudy. Lows around 67. Northeast winds 10 to 15 mph.

Monday: Sunny. Highs 72 to 81. East winds 10 to 15 mph.

Kaunakakai

Today: Breezy. Mostly sunny with scattered showers. Highs 77 to 87. Northeast winds 15 to 25 mph. Chance of rain 40 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 62 to 73. East winds 15 to 20 mph. Chance of rain 20 percent.

Monday: Sunny and breezy. Isolated showers in the morning. Highs 76 to 86. East winds 15 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Breezy trades will continue into the middle of the week, before weakening and giving way to land and sea breezes during the second half of the week. An upper level trough over the islands through Tuesday may bring some heavier showers at times, especially over interior Big Island where there will be also be a chance for afternoon thunderstorms.

Discussion

No major changes to the forecast this morning, however the winds for the Big Island summits over the next couple days was nudged upwards. Used a blend of the ECMWF and the GFS to account for the upper level trough moving over the islands which will bring some stronger, but still below advisory level, winds into mid week.
The overall forecast philosophy remains the same. A breezy trade wind pattern to remain in place through Tuesday. A mid to upper level trough has moved closer to the islands from the east overnight. The overnight soundings from Lihue and Hilo haven't shown many changes, but expect colder temperatures at the 500 mb to move in tonight.
High pressure remains far to the northeast of the islands, with a ridge north of 30N, which will maintain the breezy trade wind pattern into the middle of the week. Satellite derived precipitable water shows a drier airmass has moved over the smaller islands, and that is reflected in the Lihue sounding overnight which reported 1.12 inches. More moisture is found near the Big Island where the sounding had 1.28 inches. Several gages on the eastern side of the Big Island have reported more than an inch of rain since last evening. Anticipate additional showers over the east side of the Big Island, and to a lesser extent over Maui. The remaining islands will have some clouds overhead, but the chance for showers will be significantly lower.
A mid to upper level trough moving over the islands from the east will lead to an increasing unstable airmass over the islands through Tuesday. The trough is expected to sharpen and pivot over the islands during this time, before lifting north and then east away from the region. The global models are in good agreement that this trough will bring colder temperatures to 500 mb. The ECMWF keeps temperatures around -10/-11C, while the GFS brings in even colder temperatures of -12/-13C. These temperatures are significantly colder than normal for June. At 700 mb there isn't much different in the temperatures between these models with temperature getting to around 4/6C which is colder than normal but not as climatologically colder. Additional the coldest temperatures at 700 mb look to be focused near Kauai, while the colder 500 mb temperatures reach most of the islands. Thunderstorms were added with the afternoon package to the Big Island forecast for Monday and Tuesday afternoon, with the best chance being Tuesday afternoon. Leeward island plumes over the nearshore waters will also be candidates for nocturnal thunderstorm activity during this time, however confidence is lower so that is not currently reflected in the forecast.
The second half of the week will see the a new mid-level ridge setting up far northwest of the islands, as a front north of the islands weakens to a trough. This will cause our winds to weaken and turn to the southeast. This could lead to some land and sea breezes over the islands. With a decrease in precipitable water and a more stable airmass overhead, expect a decrease in shower activity, with clouds and showers more likely during the afternoon and evening hours over interior and southeast facing portions of the islands.

Aviation

Breezy to strong trades will continue, as a surface high moves closer to the state from the northeast. Low cigs and SHRA will favor windward and mauka areas with periods of MVFR conds possible in any SHRA. VFR conds should prevail elsewhere.
AIRMET Sierra is in effect for mtn obsc for windward Big Island and N thru SE sections of the smaller islands.
AIRMET Tango remains in effect for moderate low- level turb S thru W of terrain, as well as for moderate turb between FL300-FL400.
AMD NOT SKED for PMDY as equipment remains unavailable with no time table for return to service.

Marine

A 1028 mb surface high centered about 900 nm NE of the islands will remain nearly stationary through the remainder today. A Small Craft Advisory (SCA) has been scaled back to only include zones in the typically windy areas around Maui county and the Big Island. The high is expected to weaken slightly on Monday, but will still help to support fresh to locally strong ENE trade winds through Tuesday. On Wednesday, a frontal system approaching from the northwest will allow the high to weaken significantly, and lead to light and variable winds through the end of the week.
An extended period of elevated surf along S facing shores is now underway, with numerous swell pulses expected, mainly from the SSW. A High Surf Advisory (HSA) is likely to be needed for the largest of the swells, which may not arrive until next weekend. Nearshore buoys S of the islands continue to indicate increased energy in the longer 15-17 second period bands this morning, equating to elevated surf, but below HSA levels. This swell likely peak today into Monday, then gradually ease Tuesday before additional long-period swells arrive.
A strong, slow-moving low in the distant NW Pacific generated what will be a small NW swell when it arrives in the islands Monday and Tuesday (3 to 4 foot medium period swell from 320 direction), with the potential for a small follow- up NW swell later in the week. Trade winds will continue to generate short- period wind waves that will support choppy surf along exposed E facing shores the next couple of days.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov