Hawaii North Shore forecast by Steve Shearer (issued on Wed 27 Dec)

This week and next (Dec 29 – Jan7)

Hawaii: Small NW pulses this week with good winds, with more N swell and then stronger W/NW swell next week

Surf trends down with background HH energy through Wed. Two small back to back NW pulses from modest storms which were shunted quickly up to the Aleutians see 3ft surf Thurs, with a slightly larger pulse Fri offering 3-4ft surf, well OH at exposed breaks.

Trades veer more SE, then SSE Fri and into the weekend as a shearline through the dateline pulls a weak Kona low northwards.

Fridays pulse holds Sat, with direction veering slightly more to the N, reflecting the evolution of the storm as it was forced NNW. That should see excellent quality 3-4ft surf New Years Day, easing during the day.

Following that a severe winter storm forming north of the Aleutian arc this weekend and swinging from the Alaska Peninsula with storm force winds is aimed mostly at West Coast USA targets. The long NW fetch eventually aligns more North/South, with radial spread from this source seeing N to NNE groundswell filling in Wed in the 3ft range. 

Concurrently, W/NW swell fills in, generated by a front pushing off Honshu on the weekend. Size in the 4-6ft range is expected. Lighter E’ly trades are expected.

Longer term and storm activity increases through the western Pacific mid next week, suggesting a pattern change to a more robust and winter-calibre wave climate.

Models suggest a much broader fetch of severe gales pushing into the North Pacific in an arc from Hokkaido to the Kuril Islands during Tues/Wed next week. This fetch then tracks directly towards Hawaii for 36-48 hrs before being shunted Northwards. Another front is behind it. This indicates a stronger W/NW swell leading into the first weekend of Jan.

Check back Fri for an update.