Hawaii North Shore forecast by Steve Shearer (issued on Fri 24 Dec)

This week and next (Dec 24 – 31)

Hawaii: N/NE swell this weekend with W/NW energy next week under dreamy winds, with Kona winds ahead for New Years weekend

A large (1041 hPa) blocking high pressure remains slow moving in the Gulf of Alaska, extending storm force NW to N winds along the Eastern rim of the Pacific adjacent to British Columbia. While this fetch is aimed at targets well to the E of Hawaii, radial spread from the source is expected to maintain pulses of N/NE energy for the North Shore, holding OH energy over the weekend at N exposed spots, with a reinforcing pulse Mon. Trade-winds tend more E through E/SE over the weekend, offering better chance of quality waves at select North exposed breaks.

W/NW energy from severe gales between Hokkaido and Honshu  is expected to build surf Mon with 13-15 second period energy seeing wave heights rise to Hawaiian 4-5ft. Peaking Tues in the 6ft+ range before easing during the day. Lighter E’ly trades suggest an excellent day of surfing.

Small lows either side of Hawaii maintain lighter E’ly trades for the week, pointing to premium conditions on the North Shore as a series of small NW pulses maintain 3-4ft surf ,generated by fronts passing into the Pacific from the Kuril Islands before being absorbed in a large cyclonic gyre between Kamchatka and the Aleutian Islands. This should keep pulsing surf active through next week. A final pulse in the small series Fri is backed up by a stronger NW swell Sat, generated by a more compact fetch of severe gales to storm force winds tracking W, with seas in excess of 30ft approaching the dateline later Thurs before the storm gets shunted N towards the Aleutian Islands. 

That is expected to see surf build into the 6ft range New Years Day.

GFS model suggests an approaching trough disrupting the trade flow and generating Kona winds.

EC maintains a lighter E’ly trade flow. 

Check back Mon and we’ll see how model guidance pans out for winds.