Lighter background winds will support daytime sea breezes and nighttime land breezes today through Friday. Thus, most cloud cover and shower activity will favor interior and mountain areas during the afternoons. Deeper moisture associated with a weak trough will move northward from the southeast through Friday, and will briefly increase shower chances island-by-island as it weakens. A more typical trade wind pattern will return late this weekend into early next week.
Weak background flow will allow afternoon sea breezes and overnight land breezes to take place across the state. This will allow cloud and shower development over island interiors in the afternoon. An oncoming surface trough will continue impacting windward sections of the Big Island with light to moderate showers. The trough could also enhance shower activity over windward Maui later today. Primarily MVFR conditions are expected within showers, and brief IFR is possible under heavier showers. VFR will prevail elsewhere.
AIRMET Sierra is currently in effect for mountain obscuration across windward Kauai and Big Island. These conditions will likely last through today, and could be expanded to include other islands.
Trade winds will be mostly at gentle to moderate strength during the next few days as the surface ridge to the north remains weak and a broad surface trough moves over the islands. The weak trough is producing numerous showers across most Big Island waters this morning and will slowly move to the northwest during the next few days. Trades will gradually strengthen Sunday and Monday as the trough dissipates and high pressure builds to the north.
A series of southern hemisphere swells will continue to move through the area during the next week, though smaller than the recent large event. The High Surf Advisory finally came down early this morning, and the current south swell will remain on a very slow decline today, with PacIOOS buoys recently reporting 3.5 to 4 feet at 14 seconds. A fresh overlapping south-southwest swell will arrive overnight and will produce surf around the High Surf Advisory threshold of 10 feet on Thursday. There is no sign of the new swell on the NOAA buoys south of the islands this morning, and we will be able to get a better handle on potential surf heights later today and tonight. This swell will decline Friday, and a series of smaller south-southwest swells will maintain surf around seasonal average this weekend into early next week.
Small surf will prevail on north and east shores through most of the coming week. A slight increase in east shore surf is expected around next Tuesday or Wednesday as trade winds build across the region.
None.
