Photo Credit: Tyler Rooke

West Side

Today: Showers likely, mainly before 1pm. Partly sunny, with a high near 83. Light and variable wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Isolated showers. Partly cloudy, with a low around 67. Light east wind. Chance of precipitation is 20%.

Thursday: Scattered showers, mainly after 7am. Partly sunny, with a high near 82. Light and variable wind becoming southwest around 5 mph in the afternoon. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

South Side

Today: Showers likely, mainly before noon. Partly sunny, with a high near 83. Light north wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Partly cloudy, with a low around 65. Light north wind.

Thursday: Isolated showers. Mostly sunny, with a high near 82. Light and variable wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 20%.

North Shore

Today: Scattered showers, mainly before noon. Partly sunny, with a high near 81. South southwest wind around 6 mph becoming light and variable. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 66. East wind 6 to 11 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Partly sunny, with a high near 80. Breezy, with an east 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.

Central Maui

Today: Scattered showers, mainly before noon. Partly sunny, with a high near 81. Light and variable wind becoming north around 5 mph in the afternoon. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 64. North wind 5 to 7 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Partly sunny, with a high near 80. North northeast wind 7 to 10 mph becoming east southeast in the afternoon. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Upcountry

Today: Scattered showers. Partly sunny, with a high near 69. South southwest wind around 5 mph becoming light and variable in the morning. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Partly cloudy, with a low around 54. Light and variable wind.

Thursday: Isolated showers. Partly sunny, with a high near 68. Light and variable wind becoming west 5 to 7 mph in the afternoon. Chance of precipitation is 20%.

East Maui

Today: Scattered showers, mainly before noon. Partly sunny, with a high near 79. Light and variable wind becoming north northwest around 6 mph in the afternoon. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 62. North northwest wind around 5 mph becoming light and variable after midnight. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers. Partly sunny, with a high near 78. Light east southeast wind increasing to 6 to 11 mph in the afternoon. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Lanai City

Today: Showers likely, mainly before 1pm. Partly sunny, with a high near 74. North wind 3 to 7 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers, mainly before 7pm. Partly cloudy, with a low around 63. Northeast wind 7 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Scattered showers, mainly after 7am. Partly sunny, with a high near 74. Northeast wind 5 to 9 mph becoming light north in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Kaunakakai

Today: Scattered showers, mainly before noon. Mostly sunny, with a high near 80. North northwest wind around 6 mph becoming light and variable in the afternoon. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Partly cloudy, with a low around 68. Light east wind. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Thursday: Mostly sunny, with a high near 79. Light and variable wind becoming east around 5 mph in the afternoon.

Detailed Forecast

Synopsis

Light to moderate west to southwest winds will bring an increase in showers today, with a focus over Maui County. Passing clouds and showers will remain into Thursday as a front reaches Kauai and dissipates. Trade winds will return Thursday before diminishing again Friday as another front approaches. The possibility of inclement weather increases late Sunday and into next week.

Discussion

A front moving toward the islands from the northwest has pushed the subtropical ridge south of the islands, resulting in southwesterly winds across local waters this morning. Ragged bands of showery low clouds, embedded within this flow, are moving across the smaller islands. Radar and satellite loop shows drier and clearer conditions across the Big Island. As the front approaches, expect afternoon convection to become more vigorous over the state today as prefrontal convergence bands develop.
Winds will become northwesterlies late this afternoon as the weakening front reaches Kauai. The front is forecast to dissipate tonight across the central islands, but remaining frontal moisture will bring increased showers and cloud cover to mainly windward areas as winds flip back to northeasterly trades tonight and veer to easterlies Thursday.
Trade winds will not last long, as another approaching front is forecast to turn island winds southeast Thursday night, with widespread seabreezes expected again Friday and Saturday afternoons. Models stall the front across Kauai through Saturday before a reinforcing front pushes toward Kauai on Sunday. This has the potential to bring widespread rain late Sunday and into next week. Models disagree on the duration of this event, with GFS wanting to pass the reinforced front through the islands rather quickly, by early Tuesday. ECMWF presents a slower and wetter solution, with the reinforced front remaining across the eastern islands through next Wednesday. Details aside, days 5 and beyond will likely be quite wet for the Aloha State.

Aviation

A cold front moving into the Hawaii region from the northwest will keep light winds in the forecast veering from west to north this morning from Kauai to Maui. A prefrontal cloud band developing over portions of Maui County this morning will bring periods of increasing shower activity and lower ceilings. Trade winds return this afternoon and evening for Kauai and Oahu, spreading eastward to Maui and Hawaii Counties through Thursday morning.
A light wind regime ahead of the approaching cold front will keep isolated to scattered showers in the forecast for each island with localized land and sea breezes adding some extra variability to the wind directions. Cloud and shower patterns will then shift back to windward and mountain sections with the returning trade winds.
An upper level trough moving in from the northwest may produce some moderate clear air turbulence over the Hawaiian Islands by late morning to afternoon.
AIRMET SIERRA in effect for Tempo Mountain Obscuration over Molokai and Lanai due to low cloud ceilings and showers. AIRMET SIERRA will continue through the early morning hours.
AIRMET TANGO may also be needed later this morning for upper level moderate clear air turbulence over the main Hawaiian Islands.

Marine

A front will move southeastward and through Kauai late today, then stall out and dissipate over the central islands tonight. High pressure will slide by to the north of the state tonight and Thursday, followed by the approach of a new front Thursday night and Friday. This front will stall out and dissipate northwest of Kauai Friday night and Saturday, with yet another front moving into the islands late in the weekend into early next week. Winds will be shifting around quite a bit due to this progressive pattern over the central Pacific, but speeds should hold below Small Craft Advisory (SCA) thresholds. However, a series of large northwest swells will keep seas near or above advisory levels for the waters exposed to these swells through much of the next week.
The current northwest swell will hold steady below advisory thresholds today. A new large north-northwest swell will rapidly build from northwest to southeast down the island chain tonight, with warning level surf expected along exposed north and west facing shores tonight and Thursday. This swell will lower Thursday night and Friday, but surf will likely remain at advisory levels. An even larger northwest swell is then forecast to build Friday night, with surf expected to peak well above warning levels again on Saturday. This swell will lower Sunday and Sunday night, with yet another warning level swell due in early next week.
Surf along east facing shores will remain small through the week and over the weekend due to the lack of trades upstream of the state. Surf along south facing shores will remain small through the week, although a bit of a boost is expected from a small south-southwest swell today through Thursday.
A combination of large surf this week coinciding with peak monthly high tides will worsen beach erosion issues for shores exposed to north and northwest swells. Additionally, vulnerable low lying locations not exposed to the large swells may experience nuisance flooding at and around the peak daily tide cycles this week (between midnight and daybreak).

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov