Photo Credit: Tyler Rooke

West Side

Today: Sunny, with a high near 80. East northeast wind 5 to 9 mph becoming calm.

Tonight: Clear, with a low around 64. Light and variable wind becoming east 5 to 9 mph in the evening.

Friday: Sunny, with a high near 83. East northeast wind 5 to 10 mph becoming southwest in the afternoon.

South Side

Today: Increasing clouds, with a high near 80. Light and variable wind becoming west around 6 mph.

Tonight: Partly cloudy, with a low around 62. Calm wind becoming northeast around 5 mph after midnight.

Friday: Isolated showers after noon. Increasing clouds, with a high near 83. North northeast wind 5 to 9 mph becoming west in the afternoon. Chance of precipitation is 20%.

North Shore

Today: Sunny, with a high near 78. Breezy, with an east wind 10 to 17 mph, with gusts as high as 24 mph.

Tonight: Partly cloudy, with a low around 63. Breezy, with an east wind 11 to 16 mph, with gusts as high as 22 mph.

Friday: Sunny, with a high near 81. Breezy, with an east northeast wind 10 to 15 mph, with gusts as high as 20 mph.

Central Maui

Today: Sunny, with a high near 78. Breezy, with a northeast wind 6 to 16 mph, with gusts as high as 23 mph.

Tonight: Mostly clear, with a low around 61. North northeast wind 6 to 10 mph.

Friday: Sunny, with a high near 81. Breezy, with a northeast wind 6 to 16 mph, with gusts as high as 23 mph.

Upcountry

Today: Sunny, with a high near 67. Calm wind becoming west northwest around 6 mph in the afternoon.

Tonight: Mostly clear, with a low around 52. West wind around 5 mph becoming calm in the evening.

Friday: Sunny, with a high near 70. Light and variable wind becoming east 8 to 13 mph in the afternoon.

East Maui

Today: Scattered showers. Partly sunny, with a high near 76. East wind 6 to 10 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 59. East southeast wind 8 to 10 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Scattered showers. Partly sunny, with a high near 79. Breezy, with a southeast wind 10 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Lanai City

Today: Mostly sunny, with a high near 74. Northeast wind 6 to 11 mph.

Tonight: Mostly clear, with a low around 60. North northeast wind 6 to 9 mph becoming east after midnight.

Friday: Isolated showers after noon. Increasing clouds, with a high near 75. East wind 5 to 9 mph becoming west northwest in the afternoon. Chance of precipitation is 20%.

Kaunakakai

Today: Sunny, with a high near 79. East wind 8 to 13 mph.

Tonight: Mostly clear, with a low around 65. East wind 7 to 9 mph.

Friday: Sunny, with a high near 80. Breezy, with an east wind 10 to 15 mph, with gusts as high as 21 mph.

Detailed Forecast

Synopsis

Rather dry and stable trade wind weather will prevail during the next couple of days as a ridge holds north of the islands. Winds will shift out of the east to southeast late Friday and over the weekend, when increasing moisture moving up from the southeast will lead to an uptick in showers. Unsettled weather may develop over the islands by the middle of next week.

Discussion

Currently at the surface, a 1023 mb high is centered around 1100 miles northeast of Honolulu, while a cold front is located around 750 miles west-northwest of Kauai. Light to moderate trade winds prevail across the island chain early this morning, with some of the more sheltered leeward areas experiencing land breezes. Infrared satellite imagery shows partly cloudy conditions in most windward areas, with the exception of windward Big Island where mostly cloudy skies prevail. Meanwhile, clear to partly cloudy conditions are in place in leeward locales. Radar imagery shows scattered light showers over windward Big Island and perhaps an isolated shower affecting east Maui. Elsewhere, very little if any shower activity is present. Main short term concerns revolve around trade wind trends and rain chances through the weekend.
Today through Sunday, High pressure northeast of the state will edge further east during the next couple days, then strengthen slightly while remaining nearly stationary around 1500 miles northeast of the state over the weekend. Moderate to locally breezy trades will prevail over the eastern islands, while the western islands see light to moderate trades. Some disruption to the trade flow appears likely across the western islands Friday through the weekend however, which would bring localized sea breezes and land breezes, particularly to leeward areas. Rather dry conditions will prevail through Friday, although the airmass will gradually be modifying. Light showers will be confined to windward areas with very little shower activity expected to make it into leeward locales during this time. Precipitable water values will then climb back to normal levels Friday night through the weekend, while an upper low shifts east-southeastward to the south of the state. This should bring an increase in trade wind showers to windward areas, while also allowing for some sea breeze driven shower development in leeward areas each afternoon.
Sunday night through Wednesday, The GFS and ECMWF are in decent agreement with the large scale synoptic features, suggesting high pressure will remain anchored northeast of the state, while troughing develops to the west of the islands. Although details remain unclear at this time, the general pattern suggests southeasterly boundary layer flow bringing above normal precipitable water values over the state during this time. The southeasterly winds will keep winds light over the smaller islands, resulting in daytime sea breezes and overnight land breezes in most areas, while light to moderate east-southeast winds prevail on the Big Island. Showers will favor locations near the coast that are favored in southeast flow at night and during the morning, and interior and mauka locations during the afternoon and evening. There is the potential that the pattern could turn increasingly unsettled by the middle to late part of next week, so stay tuned.

Aviation

Latest observations indicate land breezes over Kauai and Oahu transitioning to breezy trades around Big Island and Maui, prompting issuance of AIRMET Tango for low-level mechanical turbulence there. Otherwise, prevailing VFR and light showers capable of producing nothing more than brief MVFR is expected for the remainder of the forecast period. The best chance for rain will be over Windward Big Island through this morning.
AIRMET Tango is in effect for Maui through Big Island for low- level mechanical turbulence.

Marine

High pressure northeast of the islands will generate moderate to locally breezy trade wind flow across local waters through Friday. Winds will veer a bit and decrease this weekend as a front far northwest of the islands pushes the high eastward. This front will reach northwest offshore waters next Tuesday, with north to northeast winds expected to move in behind the front.
Northwest swell forecast to arrive late Friday into Saturday will likely generate warning level surf along smaller island north and west-facing shores by late Friday night for Kauai and Saturday elsewhere. A smaller reinforcing northwest swell will move in Sunday. This reinforcing swell will either support a weekend High Surf Advisory or continue low-end High Surf Warning conditions. High surf is expect to subside Monday. No other significant swells are expected through next Wednesday.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov