Photo Credit: Laila Reiss

West Side

Today: Sunny, with a high near 85. East northeast wind 8 to 13 mph becoming light and variable in the afternoon.

Tonight: Mostly clear, with a low around 65. Light north wind.

Friday: Sunny, with a high near 85. Light and variable wind becoming north northwest around 6 mph in the morning.

South Side

Today: Isolated showers after 11am. Mostly sunny, with a high near 82. Light west northwest wind. Chance of precipitation is 20%.

Tonight: Isolated showers before 8pm. Mostly clear, with a low around 61. Light northeast wind. Chance of precipitation is 20%.

Friday: Isolated showers after noon. Mostly sunny, with a high near 81. Light and variable wind becoming east northeast 5 to 7 mph in the morning. Chance of precipitation is 20%.

North Shore

Today: Isolated showers before 11am. Mostly sunny, with a high near 83. Breezy, with an east wind around 18 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 63. Southeast wind around 5 mph.

Friday: Sunny, with a high near 82. South southeast wind around 6 mph becoming north northwest in the afternoon.

Central Maui

Today: Isolated showers before 11am. Sunny, with a high near 84. East northeast wind around 11 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 63. Light south southwest wind.

Friday: Sunny, with a high near 83. Light and variable wind becoming northwest around 6 mph in the morning.

Upcountry

Today: Sunny, with a high near 70. Calm wind becoming west around 5 mph in the afternoon.

Tonight: Mostly clear, with a low around 49. Light and variable wind.

Friday: Scattered showers after noon. Mostly sunny, with a high near 69. Light and variable wind becoming north northeast around 5 mph in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

East Maui

Today: Scattered showers. Partly sunny, with a high near 78. Southeast wind 8 to 13 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers before 8pm. Mostly clear, with a low around 66. South southeast wind 6 to 8 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Friday: Sunny, with a high near 78. South southeast wind around 6 mph becoming east northeast in the afternoon.

Lanai City

Today: Isolated showers after 11am. Sunny, with a high near 75. Northeast wind 5 to 7 mph becoming calm in the afternoon. Chance of precipitation is 20%.

Tonight: Isolated showers before 8pm. Mostly clear, with a low around 60. West northwest wind around 6 mph. Chance of precipitation is 20%.

Friday: Isolated showers after noon. Sunny, with a high near 75. Northwest wind 6 to 10 mph. Chance of precipitation is 20%.

Kaunakakai

Today: Sunny, with a high near 85. East southeast wind around 10 mph.

Tonight: Mostly clear, with a low around 63. Light and variable wind.

Friday: Sunny, with a high near 85. Light and variable wind becoming north northwest 5 to 9 mph in the morning.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will continue this morning, but will weaken this afternoon, and become light and variable by tonight. The trade winds will bring clouds and a few showers to windward areas, but showers will diminish as the winds weaken, with clear and cool conditions tonight and early Friday. Winds are expected to remain fairly light through the weekend, delivering just a few showers into next week.

Discussion

A surface ridge N of the islands is supporting moderate to locally breezy trade winds this morning, which are delivering passing showery low clouds to windward areas. A mid-level ridge extending over the area from the W continues to support a robust low-level subsidence inversion, and a relatively dry island atmosphere, with PWAT near 0.90″.
The ridge will move S over the islands tonight as yet another powerful and rapidly intensifying low passing N of the islands drives a front southward toward the area. Winds will veer to the SE this afternoon, and then become light and variable tonight in response, leading to mostly dry weather tonight and Friday. The light winds will allow for cool overnight low temperatures due to radiational cooling under mostly clear skies.
On Friday and Saturday a new high building NW of the islands will bring light N to NE winds, potentially pushing moisture associated with the dissipated front over the islands from the N and NE. Thus far guidance doesn’t indicate much of this moisture will move ashore, with the bulk of it remaining just NE and E of the islands. After the front dissipates, a surface trough is expected to linger near and NE of the islands through the weekend, with light and variable winds (or light trade winds) persisting into next week. A sharp upper trough digging southward just E of the islands on Saturday and Sunday bears watching for potential shower enhancement and/or thunderstorm development over windward waters as it cuts off into a closed low, but latest guidance indicates minimal impacts from this low aloft.
Light winds are expected to persist through early next week as the trough slowly dissipates and the surface ridge remains just N of the area. Long range guidance is indicating the potential for a more significant front to affect the islands around the middle of next week, but confidence is low.

Aviation

Breezy trades remain on the drier side for Molokai through Kauai where windward shower activity has been limited in coverage and quite light. Showers have expanded considerably in coverage near and upstream of Windward Maui and Big Island where occasional showers and brief MVFR will move in shortly and continue through the early morning hours. The gradient will diminish considerably this evening allowing land breezes to develop as skies clear tonight.
AIRMET Tango for lee turbulence will remain in effect through mid- morning.

Marine

The high pressure ridge axis north of the state is in close enough proximity for light to gentle trades to occur over the northern offshore seas. A tight enough pressure gradient still exists over the southern offshore waters from high pressure far off to the northeast that will maintain moderate trades today. Locally strong trades over the windier areas surrounding Maui and waters south of the Big Island along with 10 foot or greater seas created by the passage of large northwest swells has the Small Craft Advisory (SCA) ongoing through this afternoon. The SCA sans the Pailolo Channel, Maalaea Bay and the waters south of the Big Island this evening (due to weakened winds) has been extended into Friday morning to account for the rough seas. A trailing cold front associated with a passing North Pacific storm Friday will nudge the ridge axis into the local north waters and eventually over the state Friday into Saturday. This will significantly weaken late week winds to light and variable. As this front washes out over the region this weekend, high pressure northeast of the state will aid in reestablishing gentle trades early next week.
A series of large northwest swells will propagate through island waters the next several days. The offshore northwest buoys have been picking up on the next northwest swell energy that will be filling in this morning and producing XL surf along northern and western exposed smaller island shorelines today. NOAA buoy 51001 swell observations have been steadily rising this morning with reported 13 to 14 foot, 14 to 15 second energy. This swell energy does have the potential to peak surf at or above warning levels today and will definitely keep surf well above advisory levels along Kauai to Maui’s northern and western-exposed shorelines. The High Surf Advisory (HSA) has been extended in time for these shores through 6 AM HST Friday to account for a delayed lowering in swell and resultant surf. The next large north northwest swell arrives Saturday and Sunday. This particular swell may have more of a northerly component as it clips the northern coastal waters. A more northerly direction could sneak into those western Maui swell 360 to 010 degree windows and generate higher surf over more northern- exposed Maui shorelines. The next in this line of winter swells are timed to reach the Hawaiian waters Monday and Tuesday. Weakening trades will create relatively small, short period eastern shore surf from Friday into the weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Friday for North and West facing shores of Niihau Kauai Oahu Molokai and for North facing shores of Maui.
Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Small Craft Advisory until 6 AM HST Friday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters, Alenuihaha Channel, Big Island Windward Waters.

Data Courtesy of NOAA.gov