West Side

Today: Mostly sunny with isolated showers. Highs 76 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 66 to 75. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Sunny with isolated showers. Highs 78 to 91. East winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

South Side

Today: Sunny. Highs 78 to 89. East winds 10 to 15 mph.

Tonight: Mostly clear. Lows 68 to 73. Northeast winds 10 to 15 mph.

Saturday: Sunny and breezy. Highs 81 to 92. East winds 10 to 20 mph.

North Shore

Today: Partly sunny with scattered showers. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Gusts up to 35 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 69 to 74 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs 82 to 88 near the shore to around 69 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 82 to 89. East winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Lows 68 to 73. East winds 10 to 20 mph.

Saturday: Sunny and breezy. Highs 84 to 92. East winds 10 to 25 mph.

Upcountry

Today: Sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 54 to 69. East winds around 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 48 at the visitor center to around 45 at the summit. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Sunny and windy. Isolated showers in the morning, then scattered showers in the afternoon. Highs 56 to 72. East winds 10 to 15 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 40 percent.

East Maui

Today: Partly sunny with scattered showers. Highs 80 to 86 near the shore to around 68 near 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Gusts up to 35 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 69 to 74 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers. Highs 82 to 88 near the shore to around 69 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Lanai City

Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 70 to 80. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 60 to 68. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Sunny. Highs 72 to 82. Northeast winds 10 to 15 mph.

Kaunakakai

Today: Mostly sunny with isolated showers. Highs 72 to 89. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 60 to 74. East winds 10 to 15 mph.

Saturday: Sunny and breezy. Isolated showers in the afternoon. Highs 73 to 91. East winds 10 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A high pressure system far northeast of the state will remain in place through the next few days. Showers will favor windward and mountain areas, especially during the overnight through early morning hours. This weekend, trades will increase and much drier air will move into the region. Shower trends will increase again from Monday onward in moderate to locally breezy trade winds.

Discussion

Satellite imagery this morning shows bands of low level cumulus clouds riding into windward island mountains on the trade winds. A few wispy high cirrus clouds are drifting from west to east across the state. These clouds may enhance sunrise colors this morning. A large area of strong subsidence shows up on infra-red satellite imagery just east of 150W longitude, this area will spread a dry stable air mass across the state this weekend. A thermal hot spot over the Halemaumau Crater is associated with another round of Kilauea volcanic activity that resumed earlier this morning. A Special Weather Statement (SPSHFO) was issued for localized ashfall near the volcano region.
A high pressure ridge will remain in place north of the state into much of next week. Moderate to locally breezy trade winds today will become more breezy this weekend. Wind speeds drop back to more moderate to locally breezy levels from Monday onward.
A low level trough passing through the islands will keep brief periods of showers in the forecast today. Drier conditions will move into the region under an upper level ridge. Very low subsidence temperature inversion heights in the 4,000 to 5,000 foot range are forecast, limiting cloud and shower development on Saturday and Sunday. The combination of lower humidity levels due to the drier air mass and breezy trade winds will elevate fire concerns across the state on Sunday. Expect increasing shower trends by early next week as a combination of upper (500 mb) and lower level (700 mb) troughing move into the region. This brief passing shower activity remains in the latest forecast of both operational and blended model guidance solutions through at least next week Friday.

Aviation

A high pressure ridge remains in place north of the islands and will continue to produce moderate to locally breezy trade winds. Brief passing showers will favor windward and mountain areas.
The Kilauea Volcano resumed erupting earlier this morning with lava fountains producing an ash cloud up to around 20,000 feet above MSL. These ash particulates appear to be localized to within 5 miles of the eruption site at the Halemaumau Crater.
No AIRMETs are currently in effect.

Marine

A nearly stationary high pressure system northeast of Hawaii will continue to drive moderate to locally strong trades across the local waters for the next couple of days. The Small Craft Advisory (SCA) for typically windier waters and channels near Maui and the Big Island remains in effect through Saturday afternoon. Trade winds speeds are forecast to increase this weekend as the high strengthens, which will likely require the extension and potentially the expansion of SCA conditions across the Hawaiian waters later this weekend into early next week. Trade wind speeds could then decrease slightly by middle of next week.
A small, long-period, south swell that brought summertime average surf yesterday will gradually ease today into the weekend, dropping south shore surf to below average. Back to back pulses of slightly larger south swells are possible starting Monday which could build surf near to above advisory levels (10 ft) along south facing shores as early as Monday night into Tuesday,then remain near to above average through much of next week.
Rough and choppy conditions will continue along east facing shores and will likely pick up further Sunday into early next week as winds strengthen. Surf will remain nearly flat along north facing shores.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Saturday for the windier waters and channels near Maui and the Big Island.

Data Courtesy of NOAA.gov