Thursday, November 5, 2009

Swell Alert – Large WNW’er heading to Northern and Central California…Socal gets some scraps

This storm has been showing on the wave-height charts for days…a bright red angry meatball of 35- to 40-foot+ seas sitting right in the heart of the Gulf of Alaska.

If you have been reading the long-range forecasts, you already know that this storm formed thanks to a blending of a cold frontal low and a couple of different pockets of extra-tropical activity…one that bled into the storm track over by Japan and another that jumped into the mix just NE of the Hawaiian Islands. As usual these infusions of extra-tropical energy helped to greatly intensify the higher-latitude storm, making it both larger in size and helping to strengthen winds.

Check out what the QuikSCAT satellite is showing today…and remember this isn’t a forecast or a wave-model…these are “actual” recorded wind speeds…

This storm is managing to through together a huge area of intense fetch…40-50 knots of wind across an area approximately 1000 miles wide and 2000+ miles long…which is why the wave-models are going bonkers. Here are a couple of shots of that storm on the NOAA/GOES satellites.

On these you can see the “swirl” of the storm as the cold-front plows through a warmer air-mass positioned over the Gulf. The stuff you really want to pay attention to is the torn up clouds that follow that swirl…the winds of the storm behind the front are what is shredding the clouds.

Seeing those clouds, hopefully moving towards your location even if they are way out in the ocean, is a good thing. It means that the winds of the storm are intense enough that it is blowing both in the upper atmosphere AND along the surface…which is what we need for generating swell.

Ok I think that is enough weather nerdery for now…lets talk about the surf.

As the title of this post states…this is an Alert for Northern and Central California…not for Southern California. Yes we will get some waves from this storm pushing past Point Conception but they will be a shadow of what the directly exposed spots will be seeing.

Unfortunately for Southern California most of the storms fetch has developed a bit too far north to do us much good. Here are the swell windows overlaid on that same QuikSCAT chart…

You can see that most of the intense stuff is occurring above Socal’s NW swell cutoff, which is right about 300-degrees. However there is some less intense fetch that is in our window…so we will see some waves. (I put on the prime NW swell window for NorCal on that chart too…you can see that the strongest part of the storm is sitting right in the regions WNW-NW sweet spot.)

Northern and Central California

This new WNW-NW swell (280-320…but with most of the energy around 290-315) will start to arrive late on Friday overlapping with some energy from an earlier NW swell. I expect some large sets to begin pushing in later in the afternoon on Friday, particularly at spots North of San Francisco.

The peak of the swell will hit on Saturday Nov 7th. This swell in open water is expected to be around 15-18’ @ 15-16 second periods…pretty damn large. At this point it looks like average exposed NW spots will be easily in the double to triple-overhead range, while the better exposed spots see more consistent triple-overhead sizes …and bigger bombs mixing in. Deepwater spots, breaks that focus this sort of energy, have the potential to be a lot bigger. Spots with protection, like many of the breaks in Santa Cruz will be more manageable since the swell angle is pretty NW…not as much energy will be able to wrap around the corner. Winds and weather are a little spotty…NW winds 10 knots and some scattered rain on tap for the morning. NW winds 10-15 knots build in through the afternoon, stronger the further North you go.

The swell will hold through the day on Saturday and then start to slowly wind down on Sunday…still big with lots of double-triple overhead sets. Conditions look better as high-pressure starts to shift winds to the North-NNE for most areas. This looks like a better day overall, mostly because of the improving conditions.

Quick Note on the Maverick’s contest - it sounds like the competitors in the Mav’s contest voted not to have the contest on this swell…they want to wait for a better swell and/or better conditions. Really Mav’s likes to have some longer periods and the swell to be a little more WNW than NW to help the shape of the bowl. Whatever…these dudes are crazy. You can check the contest site (and sign up for updates) here…

Southern California

We will see this new NW swell (290-300+) start to arrive through the day on Saturday and eventually peak on Sunday before fading out on Monday.

On Saturday we will already have some surf showing thanks to a smaller storm that pushed through before the big one the day will start off with some playful NW energy in the waist-chest high range at the top spots. The new NW swell will start to show in the afternoon, particularly in the exposed areas of Santa Barbara and Ventura since they are a little closer to the action.

The new NW swell (290-300) will peak overnight into Sunday morning…by then we can expect all of the average WNW-NW facing spots, as well as a few combo spots, to be in the chest-shoulder high range. Top NW facing spots in Ventura, the South Bay, and San Diego, can expect shoulder-head high surf with overhead sets...wouldn’t be surprised to see sets going a couple of feet overhead+ at the best spots. Winds look a little funky for Sunday…so we are going to need to keep an eye on that, hopefully it is just the models acting up with storm front passing by to the north of us.

I am still being a little conservative on my wave heights for Socal…(hey I am a belt and suspenders sort of guy when it comes to this stuff)… so it is possible that we see a little more size if the later parts of this storm pull together in a better position than the charts are indicating today. I will let you know if I see anything change.


Anonymous said...

Thanks Adam for such great details Todd

Adam Wright said...

Thanks Todd...I appreciate the nice feedback, and I am stoked that you guys are mostly digging the changes.

Jason Hendrickson said...

I love the nerdery. Please post more. It's fascinating.

Anonymous said...

Adam, I appreciate your accurate forecasting, thanks and keep it up. Question for you; I leave on a private boat tonight from socal- destination, Cabo san Lucas. We are fishing and planning to surf the whole way down. Where will this swell be managable along the way? How do you think the Mag Bay area of Baja will be Weds./Thurs. next week? It would be great to know your opinion. Thanks. Austin