5-8+ foot
4-7 foot
2-4 foot
5-8+ foot

Winds will be light through the weekend due to a low pressure system moving toward the west-southwest towards the main Hawaiian Islands. The low is forecast to become nearly stationary several hundred miles north of the state by Sunday. Models indicate that the low will weaken early next week which will allow a weak high pressure ridge to rebuild over the northern offshore waters and restore light to moderate trades across the coastal waters some time Monday or Tuesday.

A north-northeast swell has been generated by the low, and while the trade wind swell is on the decline, the north-northeast swell will keep surf along east facing shores near advisory levels today. This north-northeast swell is expected to fill in Sunday night. The High Surf Advisory has been extended through Saturday evening, and may need to be extended further depending on this swell. Surf along north facing shores exposed to this swell is expected to remain below advisory levels. The direction of the arriving swell raises some concerns for surges in the Hilo, Kahului, and Haleiwa Harbors but the swell period may be too short with this event to cause significant problems.

The current north-northwest swell will trend down into the weekend. Small reinforcing south-southeast and southwest swells will keep surf from going flat along south-facing shores into next week.

Hawaii Wave Height Model

Hawaii Swell Period Model
Hawaii Swell Height Model


Tide Predictions

High tide at Kahului was 2.5 foot at 3:29 AM late last night, dropping to a low of 0.6 foot at 9:32 AM this morning, then rising to a high of 2.0 foot at 3:05 PM early this afternoon, before once again dropping to a low of -0.1 foot at 9:26 PM late this evening

The sunrise was at 06:18 am this morning and will set at 06:08 pm this evening. The Moon is currently 17 days old, and is in a Waning Gibbous phase. The next Last Quarter will occur at 12:27 PM on Thursday, October 12th.

Hawaii Wind Report

Maui Weather

90°/93°
Wind: N at 9 mph
Sunrise: 6:24 AM
Sunset: 5:55 PM
current observations as of 2pm October 22nd, 2017

Weather Outlook for Saturday

Light surface winds will prevail across the islands this weekend, which will allow local afternoon sea breezes and nighttime land breezes to develop. Moisture lingering across the area from a front that moved down across the state on Friday will result in clouds and spotty showers over parts of the islands each afternoon and evening. Clearing skies and cooler temperatures will occur at night. Trade winds are expected to return to the state early next week.

A 1008 mb surface low near 31N 150W, or about 800 miles northeast of Honolulu, is moving slowly toward the west-southwest. Remnant moisture along the trailing end of a dissipating frontal boundary, which is associated with the broad circulation around the low, remains in the vicinity of the islands early this morning. Currently, patches of low clouds with embedded isolated showers are over the windward facing slopes and the higher terrain on some of the islands, in addition to portions of the windward coastal waters, according to loops of infrared satellite imagery and radar reflectivity data. Additional low clouds and showers are over parts of the coastal waters west of the Big Island.

The surface low northeast of the islands has caused a relaxation of the pressure gradient across the region. This has resulted in the trades weakening, with a only a light background flow in the vicinity of the islands. These light winds will allow local afternoon sea breeze and nighttime land breeze circulations to develop on each of the islands through Sunday night.

The residual moisture associated with the dissipating front will be available for the development of afternoon clouds and showers over parts of the islands this weekend, especially where sea breeze circulations converge over interior sections. As nighttime cooling develops each evening after sunset, downslope winds will tend to clear out these clouds and showers. In addition, this will also produce slightly cooler low temperatures over most land areas each morning.

Note that this weather pattern is not normally conducive for significant volcanic haze (or “vog”) spreading across the smaller islands from sources on the Big Island. However, the low-level background flow may have a southeast component near the windward Big island, so Hilo and parts of the northern Big Island may have haze on Sunday. There is a chance this haze may spread as far north as Maui. Elsewhere, we are not expecting a repeat of the extensive hazy conditions we witnessed last weekend.

The forecast guidance continues to show the surface low will start to weaken north of the state Sunday and Sunday night. The pressure gradient should begin to tighten enough to allow gentle to locally moderate trade winds to return starting early next week. The trades will also begin to transport low clouds and showers toward the windward sides of the islands. Leeward sections of the smaller islands will likely be mostly dry, while afternoon clouds and upslope showers will be possible over parts of the leeward Big Island each afternoon.

During the latter half of next week, it appears that a surface trough may develop just west of the islands. At the same, the forecast guidance shows a significant increase in deep moisture brought in by low-level southeasterly flow. We will continue to monitor future iterations of the model output to determine the type of weather conditions that we might expect, assuming this scenario remains the same. The latest forecast continues to indicate increasing rain chance over parts of the state starting Thursday. We may be adjusting this forecast later this weekend, or early next week, as model depictions of this changing weather pattern become more clear.

Central Valley (Kahului, Spreckelsville):

Mostly clear. Lows around 63. Light winds.

Leeward West (Lahaina, Ka`anapali):

Mostly clear. Lows 61 to 69. Light winds.

Windward West (Wailuku, Waiehu):

HIGH SURF ADVISORY IN EFFECT UNTIL 6 AM HST SUNDAY. Partly sunny with scattered showers. Highs 70 to 84. Light winds. Chance of rain 50 percent.

Windard Haleakala (Hana, Haiku, Makawao):

HIGH SURF ADVISORY IN EFFECT UNTIL 6 AM HST SUNDAY. Partly sunny with scattered showers. Highs around 82 at the shore to around 68 at 5000 feet. Light winds becoming northeast up to 10 mph in the late morning and afternoon. Chance of rain 50 percent.

Leeward Haleakala (Kihei, Wailea, Makena):

Mostly clear. Lows around 64 at the shore to 47 to 53 upcountry. Light winds.

Haleakala Summit

Mostly clear. Lows around 41 at the visitor center to around 39 at the summit. Light winds.

Photo of the Day

Surf Photo of the Day - October 7, 2017