West Side

Today: Mostly sunny. Highs 82 to 87. East winds 10 to 15 mph.

Tonight: Mostly clear. Isolated showers in the evening. Lows 69 to 76. East winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Sunny. Isolated showers in the morning. Highs 82 to 87. East winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 90. Northeast winds 10 to 20 mph.

Tonight: Mostly clear. Lows 70 to 77. Northeast winds 10 to 15 mph.

Saturday: Sunny. Highs around 90. East winds 10 to 15 mph.

North Shore

Today: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 73 near the shore to around 54 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 83 to 91. Northeast winds 10 to 15 mph increasing to 10 to 25 mph in the afternoon.

Tonight: Mostly clear. Lows 69 to 74. Northeast winds 10 to 15 mph.

Saturday: Sunny and breezy. Highs 84 to 90. East winds 10 to 20 mph.

Upcountry

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 68 at the visitor center to around 70 at the summit. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly clear with isolated showers. Lows 45 to 57. East winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Scattered showers in the morning. Highs around 67 at the visitor center to around 70 at the summit. East winds 10 to 15 mph. Chance of rain 50 percent.

East Maui

Today: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows around 73 near the shore to around 54 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 81 to 87 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Mostly sunny. Isolated showers in the afternoon. Highs 76 to 84. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 68. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Highs 76 to 83. East winds around 10 mph.

Kaunakakai

Today: Mostly sunny. Breezy. Highs 76 to 90. East winds 10 to 20 mph.

Tonight: Mostly clear. Lows 62 to 76. East winds 10 to 15 mph.

Saturday: Sunny. Highs 76 to 91. East winds 10 to 15 mph.

Detailed Forecast

Synopsis

High pressure north of the islands will maintain moderate to locally breezy trade winds through the weekend, followed by a slight decrease in winds early next week. Stable summertime conditions will bring periods of mainly windward and mauka showers, while most leeward areas remain rather dry.

Discussion

No significant changes to the forecast this morning. The forecast has been nudged towards the latest National Blend of Models, which does boost PoPs over the windward slopes of the Big Island later today in response to an area of low clouds upstream of the islands being carried in on the trades. This solution also lowers PoPs a bit over the Big Island windward slopes on Monday and Tuesday, and the windward sides of all the islands Thursday.
Broad high pressure remains to north and northeast of the islands, with mid level ridging over the islands. Although the high is not particularly strong, the ITCZ is near 10N, making it a little further north than normal. This combination will continue to bring a stable and relatively dry weather pattern over the islands with moderate to locally breezy trades. The overnight soundings continue to show an inversion based between 5,000 and 7,000 ft, and little to no organized moisture is noted in the trade wind flow. Anticipate windward rainfall totals to remain low.
Little change is expected to the relatively dry and stable trade wind weather pattern through Sunday. Trades may ease a notch and shift out of a more easterly direction for Monday and Tuesday as the surface ridge to the north is briefly weakened. The mid-level ridge should remain strong enough to maintain stable conditions, and an area of tropical moisture may clip the Big Island on Monday or Tuesday, though odds favor the moisture passing to the south. Longer term guidance suggests moderate trades and continued modest shower activity for the second part of next week.

Aviation

High pressure remains to the north and northeast of the islands and will maintain moderate to breezy trades. Mid level ridging will help to provide a stable airmass overhead that will limited rainfall totals. Clouds and showers will remain focused primarily over the windward and mountain areas, particularly overnight and into the morning hours. MVFR conditions will be possible in showers, otherwise VFR will likely prevail.
No AIRMETs are currently in effect, and none are expected to be issued today.

Marine

A high pressure ridge north of the Hawaiian Islands will maintain fresh to locally strong trade winds through early next week. The Small Craft Advisory (SCA) was extended in time through Sunday for the windier waters and channels near Maui County and the Big Island through Saturday. This SCA will likely continue for these windier waters into early next week.
A series of small overlapping medium and long period south (170-190 degree) swells will continue through Saturday, with surf heights near the summertime average through Friday along south facing shores. Surf heights should decrease to background levels early next week as the swell energy fades. Another small, long period south swell will arrive by next week Tuesday.
Choppy conditions will continue for east facing shores through the forecast period due to the persistent fresh trades. Surf along north facing shores will remain nearly flat through next week.
Peak high tides associated with the lunar cycle will lead to minor coastal flooding along shorelines and low lying coastal areas during this afternoon's high tide. A Coastal Flood Statement remains in effect for minor coastal flooding. These coastal high water levels will decrease on Saturday.

Fire weather

Trade winds will remain in the moderate to locally breezy range into Sunday, while a ridge aloft maintains an inversion between 5,000 and 7,000 ft. Under this stable and rather dry weather pattern, relative humidity will drop into the low to mid 40s percent range each afternoon, bringing near critical fire weather conditions. We do not anticipate fire weather headlines through the weekend, but fire weather concerns will be elevated.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov