The North Pacific is starting to blow up…lots and lots of storm activity has been pulling together over the last few days and there is a lot more lining up "out the back" of the forecast run.
Already we have seen a series of new storms that has lined up a pretty large shot of WNW-NW swell for Hawaii, just in time for the O'Neill World Cup of Surfing at Sunset Beach. I watched the Web cast for a bit today—you know that Sunset is crazy big when you see sets stacking way out on third reef, and the competitors are surfing triple-overhead reform on the "normal" lineup that is now the "way inside"…crazy…and that isn't even the big swell that is still forecast to form.
Looking at the forecast charts there is a much more intense (and much larger-sized) low-pressure that is expected to develop over this upcoming weekend. It is really more than just one storm…lets go down the weather-nerdy path for a minute here…the storm is part of what is called a "complex low-pressure", which basically means that it is a series of fronts and low-pressure centers that are all mixing together in one big mess. Usually with these complex lows you have an "anchor" low-pressure that sits up in the higher-latitudes and a series of intense storms that push through the mid-upper latitudes like they are riding some crazy merry-go-round.
In this case the anchor low is currently developing, and will likely move into place over the upcoming weekend and even though it is preceding the stronger part of the storm it will be sending out its own waves as well (that will arrive a few days earlier than the larger system).
After the anchor-low repositions up over the Aleutians a second embedded low-pressure, which is the most intense part of this complex low, follows behind and gets to use all of the swell energy set up by the first front and just piles it on. Eventually these two lows blend together and sort of swing each other down into the SW portion of the Gulf of Alaska and set up a super-intense fetch for Hawaii, and to a lesser degree, California.
The current GFS pressure model is calling for the low pressure to drop to something close to 952mb, (which if this was a tropical storm/hurricane it would be something close to a category 3 system…which is why the Holy Crap is on that chart). As a frontal storm it means that winds will be close to 50-60+ knots near the core of the low. With those sort of winds, and all the pre-existing sea-state that gets kicked up by the preceding fronts, we can expect the storm to produce something that looks like this…and yes those are 40-foot+ seas.
Needless to say that even if the top 10-15-feet of that is just storm fluff there will still be a pretty significant swell forming from this storm. OK that is probably enough weather nerdy for on post…lets get on to the surf!
Hawaii is forecast to receive the largest chunk of energy…likely something in the range of 18-20 feet of deepwater energy at 17-20 seconds, which can translate to 30-40-foot faces as it hits some of the Hawaiian reefs. The swell is pretty NW'erly in swell angle, which is good for spots like Jaws (Peahi). It looks like this swell will come up fast late on Dec 6th with the peak of the swell hitting overnight into Dec 7th. One thing that could suck is the winds…the trailing part of the storm's front could show around the same time setting up W-NW winds which doesn't do the north shores of any islands any good.
Northern and Central California
Northern and Central California will see a smaller but still impressive amount of energy that will hit North of Point Conception…something like 15-16 feet of deepwater swell at 18-20 seconds. This will show some energy late on Dec 8th but will likely peak throughout the day on 9th…the angle will be pretty WNW'erly (275-295) which means that it will hit a lot more spots with more energy than the NW swells usually do.
SoCal is forecast to see this swell showing some long-period energy, particularly at the more northerly counties of Santa Barbara and Ventura, by the afternoon on the 9th. The peak of the swell will hit throughout the day on the 10th. The WNW angle works better for SoCal as well (280-300), so there will be less shadowing. At this point the swell looks good for easy head high to overhead surf at the average spots, and the top spots going several feet overhead. The best San Diego spots could see more consistent double-overhead+ sets.
Unfortunately weather looks like it may be an issue for both regions. The charts definitely show some instability, but none of them agree on how intense it will be, and they have slowly been backing off the potential storminess. I think that it is worth keeping in mind that the winds/weather may not be the greatest…but cross our fingers that conditions come through cleaner than these long-range charts think it will.
In the meantime before the big swell hits…both NorCal and SoCal can expect to see some progressively increasing WNW-NW energy as the earlier storms (like that anchor low I talked about) send in their swell. Look for new WNW-NW swell to arrive in NorCal on the 6th and SoCal on the 7th…setting up plenty of well-overhead surf at the well exposed spots north of Point Conception. SoCal will have more playful sizes with chest-shoulder high surf at the average breaks but there will still be some overhead waves at the top NW standouts.
Weather for these first swells looks a lot shakier than the end of the forecast run…it definitely looks like California as a whole will have building W-SW winds on Saturday and Sunday with some rain mixing in as well…likely pushing down into SoCal on Sunday/Monday.
Ok that is all I have for now…but make sure to check back on Monday, that bigger swell will have finally formed and I should have some good data to show you guys…expect lots of reds and purples on the charts by early next week.