4-6 foot
1-3 foot
1-4 foot
1-3 foot

High pressure will build to the north of the island chain this weekend, keeping a moderate to fresh trade wind flow in place across the coastal waters. Winds may briefly approach Small Craft Advisory levels across the typically windy waters around Maui County and the Big Island, but the forecast currently reflects winds just below SCA thresholds. A trough of low pressure is expected to develop well west of the state during the early to middle part of next week, with a potential tropical cyclone lifting northward in the vicinity of this trough, but well west of the marine area. This should ease the trade winds across the coastal waters beginning on Monday, with winds shifting around to more of a southeasterly direction Tuesday through late next week.

Small long-period south-southwest swells are expected to hold into early next week. A larger reinforcing south-southwest swell is expected to fill in Tuesday and peak on Wednesday at heights slightly above the summer average. The current short period (10-12 sec) north-northwest swell is expected to gradually decrease Sunday into Monday. A slightly larger and longer period northwest swell is expected to arrive Monday night or Tuesday and linger through mid week. A small but longer period east swell generated by east Pacific tropical cyclone Rosa may give a boost to surf along east facing shores during the early to middle part of next week. Surf is expected to remain below advisory levels along all shores through the middle of next week.

Hawaii Wave Height Model

Tide Predictions

High tide at Kahului was 2.15 foot at 2:00 PM early this afternoon, dropping to a low of 1.07 foot at 2:00 PM early this afternoon, then rising to a high of 1.63 foot at 2:00 PM early this afternoon, before once again dropping to a low of 0.17 foot at 2:00 PM early this afternoon.

The sunrise was at 06:15 am this morning and will set at 06:15 pm this evening. The Moon is currently 19 days old, and is in a Waning Gibbous phase. The next Last Quarter will occur at 9:47 AM on Tuesday, October 2nd.

Hawaii Wind Report

Maui Weather

°/°
Wind: n/a at 0 mph
Sunrise:
Sunset:
current observations as of 8am December 12th, 2018

Weather Outlook for Saturday, 29th September 2018

Summary

Tropical moisture passing the Big Island today will bring more showers and a slight chance of thunderstorms to that island. Lingering low clouds over rest of the state will slowly push westward today. Gentle to moderate trade winds will focus clouds and showers over windward and mauka sections. Drier trade wind weather is expected Sunday and Monday. Winds will weaken and veer southeast beginning Monday night through much of next week as a surface trough develops west of the main Hawaiian islands.

Detailed Discussion

Tropical moisture moving across the Big Island since late Friday night continues to bring more clouds and showers to that island. In fact, some of the moisture actually has spread north a bit, into Maui county early this morning, providing some showers to mainly windward areas. Meanwhile, lingering low clouds associated with a dissipating trough near Kauai has become somewhat active overnight, with radar picking a band of moderate showers just east to southeast of Kauai. Thus Kauai will see an uptick in showers in the next few hours. All these are carried by gentle to moderate trade winds, as an eastward moving surface high pressure far northwest of Kauai provides trade winds to the area. Unsurprisingly, both early morning Hilo and Lihue soundings indicated an increase in moisture, with precipitable waters (PW) values reaching 2 inches and higher. Interestingly, PW value is higher for Lihue sounding than Hilo’s. Also the usual trade wind inversion is missing from both soundings. Thus, airmass remains unstable.

With much moisture in the island vicinity, expect a little more clouds and showers, especially for the windward areas, to affect the islands today. Moreover, since much of the tropical moisture is still in the process of passing by the Big Island, expect a little more unstable atmospheric conditions for that island to continue. Hence, a slight chance of thunderstorms as well as locally heavy rainfall continues for the Big Island today. Meanwhile, rest of the islands will see somewhat wet trade wind weather.

A relatively drier and more stable airmass is expected to reach the islands in the next couple of days. Thus the islands will see improving weather conditions tonight. Trade wind weather will prevail with less showers for the area on Sunday and Monday.

We are continuing to monitor Invest 97C, a surface low located over 600 miles south of Honolulu early this morning. Environmental conditions are forecast to remain conducive for development over the next several days, and the low will likely become a tropical depression later today or tonight, staying well south of the main Hawaiian Islands. Latest models also continue to depict a trough deepening west of the main Hawaiian islands next week, with 97C possibly being drawn northward under the trough’s influence. This developing trough will also lead to winds over the islands veering southeast beginning Monday night, and pretty much stay southerly for the rest of next week. This means a likely return of the humid conditions to the state, with daytime sea breezes and nighttime land breezes for much of next week.

Central Valley (Kahului, Spreckelsville):

Mostly clear. Isolated showers in the evening. Lows 67 to 73. East winds up to 15 mph. Chance of rain 20 percent.

Leeward West (Lahaina, Ka`anapali):

Partly cloudy with isolated showers. Lows 68 to 75. East winds 10 to 15 mph. Chance of rain 20 percent.

Windward West (Wailuku, Waiehu):

Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 60 to 72. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Windard Haleakala (Hana, Haiku, Makawao):

Mostly cloudy with scattered showers. Lows around 70 at the shore to around 56 at 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Leeward Haleakala (Kihei, Wailea, Makena):

Partly cloudy in the evening then becoming clear. Lows around 70 at the shore to around 58 upcountry. East winds up to 10 mph.

Haleakala Summit

Breezy. Partly cloudy with scattered showers. Lows around 51 at the visitor center to around 48 at the summit. East winds 15 to 20 mph. Chance of rain 50 percent.