Hawaii North Shore forecast by Steve Shearer (issued on Mon Jan 10)

This week and next (Jan10 – Jan21)

Hawaii: Constant big surf continues with periods of tradewinds becoming established.

XL surf on Sun saw surf in the 15-18ft range with select Outer Reef exposures seeing 20ft+ sets. Large but not giant surf with excellent period and direction for Waimea Bay. Winds were light and variable early, with light seabreezes.

Reinforcing energy Mon is expected to see surf hold in the 12-15ft range with winds a bit dicey from the SW to S.

Another large W/NW swell follows close behind with an intense storm pushing storm force winds within 1500nm of Hawaii along the edge of a huge cyclonic gyre which ASCAT passes shows as inflamed by a massive area of gales to severe gales. The highly active sea state maintains large energy all week with pulses within the regime pushing surf into the 15-18ft range Tues, with light E/NE winds expected.

Again this will suit Waimea, possibly too big for Sunset and Pipe and Jaws will be shadowed by Oahu. Surf maintains size at 15ft sets Wed, slowly easing during the day, with light E’ly winds.

A similar storm force system following close behind generates another large pulse for Thurs/Fri with surf rebuilding into the 12-15ft range. Along with lighter E’ly winds this should be about the maximum the inshore reefs should hold, with plus size Pipe and Sunset on the menu.

Size slowly drops away Fri with plenty of 10-12ft surf leftover.

A compact low following behind the previous system inflames to storm force within 1500nm of Hawaii rebuilding surf to 10-12ft on Sat with light E’ly tradewinds expected. That swell eases slowly through Sun, with a smaller day ahead Mon. Likely the only day below 10ft in the near term.

Into next week and the storm action continues to come hot and heavy off Japan. Another large storm forms a cyclonic gyre over the western North Pacific on the weekend, (see below) with large surf next Tues likely to push back into the 12-15ft range.

More swells are expected, through the following week, although the longer range EC does point to swells becoming a bit more subdued as the storm track contracts away from Hawaii, leading to smaller W/NW swells into the longer term. GFS maintains a full strength storm track with L to XL NW to W/NW swells continuing.

Long range is subject to low confidence.

Check back Wed for the latest.