West Side

Tonight: Partly cloudy with isolated showers. Lows 69 to 76. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 82 to 87. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Saturday Night: Partly cloudy with isolated showers. Lows 69 to 76. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Tonight: Mostly clear. Lows 69 to 78. Northwest winds up to 10 mph.

Saturday: Sunny and breezy. Highs around 90. North winds up to 20 mph.

Saturday Night: Partly cloudy. Lows 68 to 77. North winds 10 to 15 mph.

North Shore

Tonight: Mostly cloudy with scattered showers. Lows around 73 near the shore to around 53 near 5000 feet. Southeast winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Saturday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Saturday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 72 near the shore to 50 to 55 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Central Maui

Tonight: Mostly clear. Lows 69 to 74. East winds up to 15 mph.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 83 to 90. East winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Saturday Night: Partly cloudy. Isolated showers after midnight. Lows 69 to 74. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 50 at the visitor center to around 48 at the summit. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 20 percent.

Saturday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 65 at the visitor center to around 68 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Saturday Night: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows 45 to 56. East winds 10 to 20 mph. Chance of rain 50 percent.

East Maui

Tonight: Mostly cloudy with scattered showers. Lows around 73 near the shore to around 53 near 5000 feet. Southeast winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 50 percent.

Saturday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Saturday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 72 near the shore to 50 to 55 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Lanai City

Tonight: Partly cloudy. Lows 64 to 69. Light winds.

Saturday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 74 to 83. Northeast winds up to 20 mph. Chance of rain 20 percent.

Saturday Night: Mostly clear. Lows 64 to 69. Northeast winds 10 to 15 mph.

Kaunakakai

Tonight: Partly cloudy with isolated showers. Lows 60 to 76. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 74 to 90. East winds 10 to 20 mph. Chance of rain 20 percent.

Saturday Night: Mostly clear. Lows 60 to 75. East winds 10 to 15 mph.

Detailed Forecast

Synopsis

Gentle to moderate east-southeast winds will continue through Saturday morning in response to an approaching cold front in the North Central Pacific, allowing localized daytime sea breezes and overnight land breezes to continue. Moderate trades are forecast to build back late Saturday and remain into early next week as a new high builds north of the state.

Discussion

Gentle to moderate east-southeast winds will continue through Saturday morning in response to an approaching cold front in the North Central Pacific. The front will stall out north of the islands and so will not have a direct impact on our weather. 12Z soundings show relatively stable conditions, with the inversion between 6000 to 7500 feet and precipitable water values of 1.54 inches at Lihue and 1.29 inches at Hilo.
Current radar and satellite data show low clouds and scattered showers mostly passing by the islands offshore, but occasionally coming onshore as plume showers impact islands downstream (to the northwest). Main impacts overnight were concentrated across Molokai, Lanai and windward Oahu. Showers should taper off through the morning hours before clouds build up this afternoon over all island interiors as sea breezes dominate due to wind blockage from the Big Island. The plume showers will likely set up again tonight and impact the smaller islands at times, otherwise land breezes will work to keep showers offshore.
Latest models indicate easterly trades will build back into the region Saturday afternoon and continue into early next week as a new surface high develops and strengthens far to the northeast of the state. Clouds and showers will again focus back to windward and mauka areas. A broad surface trough will develop northeast of the state around Monday and slowly track westward across the island chain through the middle part of next week. Winds will again taper off and put us in a land and sea breeze regime, but forecast confidence is low for placement of any showers as this feature moves through the state.

Aviation

East southeast flow with embedded showers will continue this morning. Land breezes have kept most showers offshore, but plumes developing off Molokai will bring showers to windward and southeast Oahu this morning, where AIRMET Sierra is posted for tempo mountain obscurations above 2500 feet. VFR conditions prevail elsewhere with isolated MVFR ceilings and visibilities around the showers. AIRMET Sierra could also be issued for any of the smaller islands through the morning if the plume showers push into the islands.
For this afternoon, expect to see cloud build ups over island interiors as sea breezes dominate due to wind blockage from the Big Island. AIRMET Sierra could also be possible across leeward/interior sides of the islands this afternoon due to the extensive clouds and showers. Low level wind shear possible over PHOG today.
Land breezes will clear out islands tonight with the possibility of plume showers lining up across the smaller islands and overriding the land breezes and bring additional showers to southeast slopes.

Marine

Surface high pressure northeast of the state will continue to drift east a front moves north of the area. Light to moderate east southeast winds have developed over the forecast waters and will hold today giving way to localized land and seabreezes over leeward waters. High pressure will build in from the northwest allowing moderate to locally fresh trade winds to return Saturday through Sunday. A trough may develop northeast of the state early next week, weakening winds to light and variable.
The current small medium period northwest (310-320 deg) swell from Tropical cyclone Neoguri will decline today. A moderate, medium period north northwest (330 deg) swell generated from the current low located far north northwest of the islands is expected to fill in on Saturday, peak Sunday just below High Surf Advisory (HSA) criteria for north facing shores, and slowly fade into early next week. Another small medium to long period swell from the northwest (320 deg) is expected to fill in Monday, peak Tuesday and decline through the middle of next week.
The current small, long period southwest (210 deg) swell will continue will peak today before slowly declining into early next week. Another small, long period southwest swell may arrive late Sunday and build into early next week before subsiding. Surf along east- facing shores will remain below average into early next week with the a slight boost Saturday into Sunday as moderate to fresh trades briefly return.

Fire weather

Wind speeds and humidity will remain below critical fire weather thresholds for the next seven days. Temperature inversion heights across the state will range from 6000 to 7500 feet today.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov