10-15+++ foot
8-12++ foot
1-3 foot
2-4+ foot

A ridge will remain just north of Kauai through today, while a front enters and dissipate over the far northern offshore waters. The ridge will maintain a light easterly wind flow across the main islands through today. The demise of the front will allow for the ridge to strengthen and the trades to rebound to moderate to locally strong speeds tonight. There is a possibility that the strong trades may extend beyond the typically windy marine zones of Maui County, the Alenuihaha Channel and waters south of the Big Island. A Small Craft Advisory is currently in effect for most of the near-shore waters across the main Hawaiian Islands due to above normal seas related to the large northwest swell. An SCA due to the strengthening trades will be issued later today.

The moderate to locally strong trade collapses on Wednesday as a front approaches the islands from the W. While the winds weaken over the immediate waters, they will also be veering to the south and south-east between Wednesday night and Thursday. During this time, breezy southerly winds will develop over the western offshore waters, ahead of a front that will be entering the far northwest portion of the offshore waters Thursday evening. Strong southerly winds will be subsiding to moderate speed while the front is moving across the western Hawaiian Islands on Friday. Expect the front to reach Kauai early Friday, Oahu Friday afternoon, and Maui County late Friday night. A light to moderate northwest wind flow follows in behind the front.

The second and larger swell reached buoy 51001, located 180 nm northwest of Kauai a couple of hours ago, maxing out at 22 feet. Thus, the surf forecast was upped another 5 feet for the north facing shores. This event will be the largest surf of the young season for the north and west facing shores. As mentioned earlier, an SCA is already in effect over most waters for seas above the 10 foot threshold. This SCA is good through Tuesday.

In addition to the life-threatening surf expected for a long period, impacts could also include significant beach erosion and overwash onto vulnerable low-lying coastal areas especially during the peak of the high tide near daybreak for the next couple of mornings. The large northwest swell will also cause surges in harbors and breaking waves at harbor entrances such as Haleiwa, Waianae, and Kahului Boat harbors.

Choppy surf will return along east facing shores by midweek as the trades return.

Small surf will continue along south facing shores with mainly background southern Pacific pulses moving through the first half of this week.

Hawaii Wave Height Model

Tide Predictions

High tide at Kahului was 2.72 foot at 2:00 PM early this afternoon, dropping to a low of 0.99 foot at 2:00 PM early this afternoon, then rising to a high of 1.24 foot at 2:00 PM early this afternoon, before once again dropping to a low of -0.16 foot at 2:00 PM early this afternoon.

The sunrise was at 06:42 am this morning and will set at 05:44 pm this evening. The Moon is currently 18 days old, and is in a Waning Gibbous phase. The next Last Quarter will occur at 12:21 AM on Friday, November 30th.

Hawaii Wind Report

Maui Weather

°/°
Wind: n/a at 0 mph
Sunrise:
Sunset:
current observations as of 5pm January 15th, 2019

Weather Outlook for Monday, 26th November 2018

Summary

A deep trough across the Central and Eastern Pacific with a weak cold front north of the islands will produce light winds today with trade winds slowly increasing later this afternoon as high pressure builds north of the islands. A weak high center will move north of the islands on Tuesday and bring a return to moderate to breezy trade winds with isolated to scattered showers through Wednesday. A stronger cold frontal system approaches the islands on Thursday with scattered showers and southerly winds. By Friday and Saturday a cold front will sweep through the islands with numerous rain showers across the state and locally heavy rain possible in some areas. Periods of showers will linger into Sunday across the Big Island. Drier and cooler air will move in behind the front.

Detailed Discussion

A zonal polar jet stream pattern over the North Pacific will keep low and high pressure systems moving rapidly from west to east through the end of the work week. This means the Hawaiian Islands will see rapid changes in local area weather conditions this week. Expect a transition from a light wind pattern with localized sea breezes to trade winds later today, with moderate to breezy trade winds from Tuesday into Wednesday, a prefrontal southerly wind pattern on Thursday, and a cold front sweeping west to east across the island chain from early Friday morning through Saturday. Showers will then linger on Sunday over the Big Island with a weakening frontal boundary as colder drier air moving in behind the frontal boundary reaches the smaller islands.

A light wind regime with localized sea breezes in the morning will transition to increasing trade winds by afternoon as high pressure slowly builds north of the state. Clouds will tend to build over windward mountain and interior sections of each island as a weak low level trough will help produce isolated to scattered showers over the islands.

On Tuesday and Wednesday, a weak 1024 MB surface high will move across the Central Pacific just north of the islands. Increasing surface pressure gradients will cause moderate to breezy trade winds to return briefly through Wednesday. Rain shower activity will pick up as stronger winds converge over the mountain ranges with scattered showers forecast favoring windward and mountain areas. More isolated shower activity is possible over leeward slopes of all islands, mainly in the overnight hours, during this period.

By Thursday, a stronger cold frontal system will approach the islands from the northwest. This frontal trough will weaken the ridge as the high center drifts eastward producing southerly prefrontal winds. Scattered prefrontal showers may develop during this period as the subsidence inversion aloft weakens and additional tropical moisture is drawn northward over the state.

On Friday and Saturday, a more active cold front will sweep across the state from west to east with numerous to frequent showers expected along the frontal zone. The latest model guidance shows clouds and showers along this frontal boundary reaching Kauai early Friday morning just after midnight, reaching Oahu around sunrise on Friday, and Maui County from Friday afternoon into Saturday morning. The Big Island may see convective showers develop along a prefrontal convergence line by Friday night with the cold front arriving by Saturday afternoon.

The American (GFS) model continues to show a 500 MB trough supporting convection along the frontal zone possibly producing locally heavy rain showers and a few thunderstorms. The European (ECMWF) model shows a similar weather pattern with the low center tracking a bit further north with lower precipitation amounts as compared to the GFS model. Either way we are forecasting a 12 to 24 hour period of rainfall activity over each island with this frontal passage. Model run to run consistency is improving our confidence in the timing of this wet weather event.

From Sunday onward expect breezy northerly winds with cooler and drier air moving in behind the front with clouds and showers slowly clearing from west to east after frontal passage. Scattered shower activity will linger over the Big Island as the southern section of the front slows down.

Central Valley (Kahului, Spreckelsville):

HIGH SURF WARNING IN EFFECT UNTIL 6 PM HST TUESDAY. Mostly sunny. Isolated showers in the afternoon. Highs 80 to 86. North winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Leeward West (Lahaina, Ka`anapali):

Partly cloudy. Breezy. Isolated showers in the evening. Lows 65 to 71. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Windward West (Wailuku, Waiehu):

HIGH SURF WARNING IN EFFECT UNTIL 6 PM HST TUESDAY. Breezy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 68 to 82. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Windard Haleakala (Hana, Haiku, Makawao):

HIGH SURF WARNING IN EFFECT UNTIL 6 PM HST TUESDAY. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 78 at the shore to around 67 at 5000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Leeward Haleakala (Kihei, Wailea, Makena):

Breezy. Partly cloudy with isolated showers in the evening, then clear after midnight. Lows around 67 at the shore to 51 to 56 upcountry. East winds up to 20 mph. Chance of rain 20 percent.

Haleakala Summit

Partly cloudy. Isolated showers in the evening, then numerous showers after midnight. Lows around 44 at the visitor center to around 40 at the summit. Northeast winds 10 to 15 mph. Chance of rain 70 percent.