Hawaii North Shore forecast by Steve Shearer (issued on Wed 22nd Dec)

This week and next (Dec 24 – 31)

Hawaii: A mix of dominant N/NE short period swell and smaller NW swell, with fresh E/NE trades. Biggest surf at N swell exposed spots.

A strong high drifting into the Gulf of Alaska towards the west coast is maintaining a firm ridge extending from the coast of British Columbia into the Central North Pacific,  with angular spread from the predominant N’ly fetch producing a N/NE swell for Hawaii’s North Shore. This holds surf in the OH to well OH range at Northern exposures Wed/Thurs, albeit a bit raggedy from fresh E/NE trades. A reinforcing pulse from the same direction Fri rebuilds surf at similar sizes. 

Another intensification of the N’ly fetch along the British Columbia coast during Fri/Sat, extending into Californian latitudes is mostly too Far East to be in the swell window for Hawaii, but angular spread from high seas will some more longer period N/NE swell glance Hawaii in the 3ft range on Tues 28.

The semi-stationary high maintains a steady drumbeat of swell from the NE through the weekend and early next week, with a more E’ly tilt to trades potentially improving surf quality at more N exposed breaks.

A quick blast of severe gales out off Hokkaido Wed/Thurs is limited by fetch length and duration but should see a pulse of mid period W/NW swell arriving Mon with size in the 2-3ft range. Easing through Tues after peaking with 3ft sets.

A following system in the same area reaches over the dateline but with weaker winds through Fri/Sat, suggesting a stronger but still mid period NW pulse arriving Thurs/Fri in the 3-4ft range, with more E’ly Tradewinds expected.

A modelled Kona low to the west of Hawaii early next week sees potential for E’ly Tradewinds to get a more E/SE to SE angled flow.

The storm track through the end of next week remains suppressed, with disjointed storms quickly shunted NE towards the Aleutian Islands and the strongest winds aimed away from Hawaii. That suggests a quiet start to the New Year under a La Nina influenced North Pacific.

More in the next update.