Breezy to locally windy trades are expected today, then moderate to breezy trades will persist through the rest of the week and deliver periodic showers to windward and mountain areas. Tropical Cyclone Fausto (or its remnants) may impact the state towards the middle of next week, but it's too early to determine potential impacts.
A strengthening high pressure system north of the Hawaiian Islands will increase trade wind speeds today, with the peak of the winds expected this afternoon. AIRMET Tango remains in place for mechanical turbulence to the lee of the mountains as a result. Anticipate this AIRMET to remain in place through Friday morning.
Some clouds and showers riding in on the trade wind flow will bring passing MVFR conditions mainly along windward mountain slopes. Otherwise, VFR conditions are expected to prevail.
High pressure far north of the state will maintain fresh to locally strong trades through the weekend. A Small Craft Advisory (SCA) is in effect for all Hawaiian waters through tonight. Widespread fresh to strong winds are expected during this time with near gales possible for the windier waters around Maui County and the Big Island. The strong high to the north is expected to eventually shift westward and weaken some, which should allow the trade winds to weaken a notch around Sunday evening. Trends in the strength and direction of winds early next week become less clear as a result of the uncertain track of a weakening Hurricane Fausto (forecast to become a tropical storm by Monday) in the central Pacific.
Long period south swell energy is expected to continue to build through the day, allowing surf along south-facing shores to increase this afternoon into tonight. A High Surf Advisory (HSA) is in effect today for advisory level surf with potential for surf to build closer to warning levels tonight into Friday as the swell peaks. Over the weekend, reinforcing long-period energy may allow advisory level surf to persist and may require an extension of the HSA. The swell will then slowly decline into the beginning of next week.
Surf along east-facing shores will remain rough and choppy, with a small, medium- period east swell which was likely generated by former TC Elida. This weekend, larger surf generated by Hurricane Fausto is possible and could bring advisory level surf along east facing shores by late Sunday into early next week.
Surf along north-facing shores will remain at flat to tiny levels through the weekend.
High Surf Advisory until 6 AM HST Friday for Big Island South- Big Island Southeast-East Honolulu-Ewa Plain-Honolulu Metro- Kahoolawe-Kauai South-Kauai Southwest-Kona-Lanai Leeward-Lanai South-Maui Central Valley South-Maui Leeward West-Molokai Leeward South-Niihau-South Haleakala-South Maui/Upcountry- Waianae Coast.
Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.
