A strong high pressure system far north of the Hawaiian Islands will continue to produce moderate to breezy trade winds today with periods of showers favoring windward mountain areas in the overnight and early morning hours. Hurricane Fausto remains on track to pass north of the Hawaiian Islands on Tuesday and Wednesday as a tropical storm. A drier and breezy trade wind weather pattern will return across the state from Thursday onward as Fausto drifts westward away from the Hawaiian Islands.
Trades will weaken slightly and back towards the northeast today, then weaken further Tuesday. Typical trade wind showers with low ceilings are expected over windward and mauka areas with limited spillover into leeward areas. MVFR conditions are likely in heavier showers, but otherwise we will see VFR. Hurricane Fausto is east of the state moving WNW and is forecast to pass to the north Tuesday night through Wednesday night. TC SIGMET Sierra covers Fausto.
AIRMET Sierra is in effect for mtn obsc for windward portions of the smaller islands. Conds may improve late this morning.
AIRMET Tango remains in effect for mod low-level turbulence downwind of island terrain. This AIRMET may be dropped this afternoon as winds continue to decline.
An overnight ASCAT pass revealed that locally breezy trade winds continue to prevail over the region, especially in the typically winder waters and channels around Maui County and the Big Island. Therefore, a Small Craft Advisory remains in effect for these areas through this afternoon. The fresh to locally breezy trades will gradually shift to the NNE and diminish through the middle of the week in response to what is currently Hurricane Fausto passing north of the islands. However, it is likely that the Small Craft Advisory will need to be expanded due to seas greater than 10 feet for windward waters. The trades will then return to fresh and strong levels late this week into the weekend as the remnants of Fausto continue off to the west-northwest away from the state and strong high pressure builds to the north.
Nearshore buoys on the eastern side of the islands have shown an uptick this morning with the medium and long period energy. The High Surf Advisory for east facing shores was upgraded to a High Surf Warning as the buoys are running above model guidance and surf is expected to build through the day and tomorrow. The High Surf Warning is in effect through Wednesday afternoon. A Coastal Flood statement may be also be needed during the peak of the large surf for vulnerable low-lying coastal roadways, docks, boat ramps, and other coastal infrastructure exposed to the large east swell. After a brief lull late Wednesday through Thursday, east shore surf will trend back up Friday into the weekend due to a combination of rising trade wind swell and a new long period east swell generated by Hurricane Genevieve.
The current long-period south swell will remain elevated today before slowly declining through the week.
Surf along N shores could also see some brief increase as Fausto (or its remnants) pass near the region Tuesday and Wednesday, then return to typical flat to tiny levels late Wednesday into the weekend.
High Surf Warning until 6 PM HST Wednesday for Big Island East- Big Island North-Big Island Southeast-East Honolulu-Kauai East- Kipahulu-Koolau Windward-Maui Windward West-Molokai Southeast- Molokai Windward-Olomana-Windward Haleakala.
Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha Channel-Big Island Southeast Waters-Big Island Windward Waters- Kaiwi Channel-Kauai Northwest Waters-Kauai Windward Waters-Maui County Windward Waters-Oahu Windward Waters-Pailolo Channel.
