Photo Credit: Tyler Rooke

West Side

Today: Isolated showers before 1pm. Sunny, with a high near 85. East wind around 6 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 69. East northeast wind 3 to 7 mph.

Monday: Sunny, with a high near 85. East northeast wind 5 to 7 mph becoming calm in the afternoon.

South Side

Today: Sunny, with a high near 82. East northeast wind around 6 mph becoming calm in the morning.

Tonight: Mostly clear, with a low around 64. Calm wind becoming east northeast around 6 mph in the evening.

Monday: Sunny, with a high near 82. Calm wind becoming east northeast 5 to 7 mph in the afternoon.

North Shore

Today: Isolated showers. Mostly sunny, with a high near 82. Breezy, with an east wind 14 to 17 mph, with gusts as high as 23 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 67. Breezy, with an east wind 11 to 16 mph, with gusts as high as 23 mph. Chance of precipitation is 20%.

Monday: Isolated showers. Mostly sunny, with a high near 83. East wind 11 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 20%.

Central Maui

Today: Isolated showers before noon. Mostly sunny, with a high near 82. Northeast wind 9 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 20%.

Tonight: Isolated showers after midnight. Partly cloudy, with a low around 66. East northeast wind 5 to 13 mph. Chance of precipitation is 20%.

Monday: Isolated showers. Mostly sunny, with a high near 84. Northeast wind 5 to 10 mph. Chance of precipitation is 20%.

Upcountry

Today: Mostly sunny, with a high near 70. East southeast wind around 6 mph becoming calm in the morning.

Tonight: Mostly clear, with a low around 53. East wind 3 to 6 mph.

Monday: Mostly sunny, with a high near 71. Calm wind becoming east 5 to 8 mph in the afternoon.

East Maui

Today: Showers likely, mainly before noon. Partly sunny, with a high near 77. East wind 9 to 13 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 69. East southeast wind 9 to 13 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 77. East southeast wind 9 to 11 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Lanai City

Today: Isolated showers after noon. Mostly sunny, with a high near 75. East northeast wind 10 to 14 mph, with gusts as high as 18 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 62. East northeast wind 9 to 14 mph becoming light northeast after midnight. Winds could gust as high as 18 mph.

Monday: Isolated showers after noon. Mostly sunny, with a high near 75. Calm wind becoming east northeast around 6 mph in the afternoon. Chance of precipitation is 20%.

Kaunakakai

Today: Isolated showers before noon. Mostly sunny, with a high near 85. Breezy, with an east wind 9 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

Tonight: Mostly clear, with a low around 70. East wind 6 to 14 mph, with gusts as high as 18 mph.

Monday: Sunny, with a high near 85. East wind 6 to 13 mph.

Detailed Forecast

Synopsis

A ridge of high pressure far north of the state will gradually weaken and will cause the trade winds to weaken to moderate speeds by Monday. Showers should become less frequent with the diminishing trades, but passing showers are still expected mainly over windward and mountain areas. Trades are expected to pick up towards mid week, but may become light and variable towards the end of the week in response to a front passing north of the state.

Discussion

A ridge of high pressure several hundred miles north of the state will gradually weaken over the next few days and shift closer to the state in response to a front passing far north of the area. This will allow the trade winds to weaken to moderate speeds by Monday.
But for today, we should continue to see breezy trade winds across the state with scattered showers riding in with the trades especially during the morning hours. By Monday, trades should lower to moderate speeds and should hold at moderate speeds through Tuesday. With the lowering trades, showers should become less frequent, but they will continue to ride in with the trades from time to time. Expect passing showers to favor windward and mountain areas, especially during the night and morning hours. Total rainfall amounts will be light due to a stable atmosphere.
Towards the middle of the week, an increase of trades to fresh speeds is expected as a new high builds north of the state. By the end of the week, models are in fairly good agreement with a front passing north of the state, causing winds to turn light and variable across the smaller islands.

Aviation

Breezy trades will continue today, then slowly trend down tonight into Monday as the ridge to the north weakens. Although VFR conditions will prevail through much of the 24-hr period, spotty windward showers will bring brief periods of MVFR CIGS/VSBYS – mainly overnight through the early morning hours.
AIRMET Tango remains posted for low-level turbulence south through west of mountains over all islands, which will continue today.

Marine

A ridge of high pressure north of the state will keep fresh to strong trades in place through tonight. The trades will ease to moderate levels Monday and Tuesday as a front approaches from the northwest, then re-strengthen to locally strong levels around the middle of the week. A Small Craft Advisory (SCA) remains in effect for the windier areas around Maui and the Big Island through 6 AM Monday. Elsewhere, the SCA has been cancelled as winds and seas have fallen below advisory thresholds. Seas will likely rise back up to SCA levels tonight, and remain at SCA levels through much of the week as a series of large northwest swells move through.
The NOAA offshore buoys 51001 and 51101 are running 2 to 3 feet below WW3 guidance this morning, with the spectral density data only registering a small hint of the anticipated long-period north-northwest swell as of 3 AM. As a result, the surf along north and west facing shores should remain well below advisory levels through the day today, and have adjusted the surf forecast accordingly. The new north-northwest swell is expected to build tonight, with surf possibly reaching High Surf Advisory levels by daybreak Monday. If surf fails to reach advisory levels tonight, surf should quickly rise to advisory levels along exposed north and west facing shores Monday morning, then hold at advisory levels through Tuesday. A new larger long-period north-northwest swell is forecast to build Tuesday night, and be reinforced by another large north-northwest swell Wednesday night and Thursday. The combination of these swells may produce warning level surf along exposed north and west facing shores Wednesday through Thursday. This latter north-northwest swell will then lower Friday through next weekend, with surf forecast to drop below advisory levels by Friday night.
Trade wind swell will be on the decline over the next several days as the trades ease, keeping east shore surf on the small side through much of the week. South shore surf will remain small through the coming week as well.
Although lowering daily tidal ranges will limit the extent of the wave runup next week, overlapping large northwest swells described above will only worsen the ongoing coastal erosion issues for vulnerable shores exposed to north and west swells. Peak monthly tides for January are expected from the 10th through the 15th.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov