Over the past week, Hawaii has held the attention of the surfing world thanks to an XXL swell arriving under perfect conditions. That swell saw the Eddie run and won by Luke Shepardson, flawless outer reefs, plus Jaws putting on yet another show.

With the Billabong Pro Pipeline starting shortly - the waiting period begins on January 29th - the surfing world remains focussed on Hawaii, but has there been any change to the early outlook?

In one word, yes, but only slightly, and for the better.

The general synoptic pattern is holding with a blocking high setting up camp to the north-east of the islands (see image below), however a large swell is now due to arrive through the opening day of the waiting period.

This is being generated by a significant storm that's currently causing chaos across Japan, with a wide fetch of W/NW gales due to reach severe-gale-force in strength today while projecting east into the North Pacific Ocean.

The storm will stay a far distance away from Hawaii thanks to the blocking high, but regardless of distance, a large, long-period NW groundswell is expected to build rapidly on Sunday, reaching 10-12ft into the afternoon.

This is where the position of the blocking high makes for troublesome local conditions when the swell arrives. A series of troughs/lows are forecast to form along the north-eastern flank of the high - i.e north of Hawaii - projecting south, squeezing pressure gradients across the islands.

Therefore, as the long-period NW groundswell builds on Sunday, strong NE winds will create very tricky conditions. The winds will improve a touch on Monday while remaining strong from the E/NE as the swell eases from the 10ft range on the sets.

Any wind shift to a more northerly direction (as one of the forecast models has) will completely write-off this swell. We'll watch this aspect very closely.

The swell will continue to fade through Tuesday with gusty E/NE-NE trades, shifting slowly more easterly into the middle to end of the week.

The activity north of the islands should generate some mid-period northerly swell through Wednesday afternoon and Thursday to 6ft+ or so. With the local winds and swell direction Backdoor should offer contestable waves.

The outlook beyond this remains uncertain as storms try to fire up off Japan but are deflected away to the north-east by the stubborn blocking high. We'll continue to monitor this dynamic outlook and provide updates over the coming week.

Click for Swellnet's North Shore forecast and WAMs