Saturday, December 03, 2016

6.30am Hookipa has inconsistent nw head high to occasional overhead sets mixed with the windswell.
Light sideoff. 5

12 3 16 morning call

Yesterday I monitored the slow rise of the NW swell all morning and then I decided to surf the windswell instead and pulled a rabbit out of the hat scoring a very fun session with just a friend and I.

I don't have an action shot, here's a surreal December 2016 sunset by Jimmie Hepp.

4am significant buoy readings
South shore
Both Lanai and Barbers are "overwhelmed" by the WNW swell, the only way to check the size of the waves in Lahaina is through the webcam. The map below is from a week ago Saturday Nov 26 and it shows a strong fetch in the Tasman Sea, so it might be worth doing that. I noticed that those Tasman Sea swells take a bit longer than the ones coming from a straight south direction, so it might be a bit early for that. It's like there's more traffic on that SSW highway.

North shore
7.8ft @ 13s from 312° (NW)

7ft @ 14s from 320° (NW)

8.1ft @ 10s from 82° (E)           
3.5ft @ 16s from 328° (NW)
Below is the graph of NW, Hanalei and Pauwela and the sizes the swell reached respectively were: 8, 7 and 4 feet. I spent plenty words (probably too many) in yesterday's post to explain the reason for that. I actually added more explanations about refraction later in the morning, so read it again if you're interested in such topic.

For today we can expect the swell to hold to similar sizes eventually coming down a second or two with the period.

This is the Surfline forecast that I posted on Dec 1st. I'm posting it again to show a pretty rare case in which it was a bit off with the numbers. The 4am arrow was 4f 18s, while Pauwela instead read 3f 18s at that time. Then they called it to go up to 6 feet, instead it only went to 4f. It's so difficult to predict the effect of the refraction, that I don't feel like calling that forecast all that wrong at all, really. The curve and timing was still spot on if you compare it with the Pauwela graph.
I'm pretty sure the tab with the wave faces numbers was much more off, but, as I often repeat, I never even look at those.

Couple of words about the contests. I only watched heat 1 of round 3 of the ladies at Honolua (Tatiana on a tear!) and then judged it too slow/small to be entertaining... this year they have been unlucky. So I swapped to the Sunset Beach one, but I'm still watching day 1, so I don't know how it was yesterday, but I'm sure it was pumping. Both contests should still be on today.

Current wind map shows:
- a decent fetch in the NW corner
- a tight, bit crooked N fetch
- the windswell fetch

NAM3km map at noon shows a bit of an onshore flow, so catch the waves in the morning!

This is the 5pm map instead and it shows a bit of a Kona flow. Waves should be very clean at sunset, but I work till 6 and right after that I'm gonna go to the MACC and ask William Finnegan a question I have since I read his wonderful book "Barbarian days". Best surfing book I've ever read.

Friday, December 02, 2016

8am Hookipa has well overhead inconsistent nw sets mixed with windswell peaks.
Wind is light and sideoff. 5

12 2 16 morning call

Usually I'm out the door at first light, but yesterday the weather on the north shore was so bad that I only made it out of the house by noon. Just in time to catch one of the very few Hookipa sailable windows of the day though. Despite the strong wind, the waves were fun (the windswell had moments of semi-organized 10-11s period sets).

In the afternoon I had to work and part of my job is to continue to keep checking the conditions so that I can offer the best advices to my rental customers. I laugh inside when the poor unaware customers ask me if I know how the conditions will be for their stay... 'cause they have no idea of the amount of detailed information they're about to get! :)

That is a photo of the computer screen that shows the webcams of Pipeline on the left, Sunset Beach on the right and at Hookipa at the bottom around 5.30pm yesterday. Fore sure our Oahu neighbors had a better sunset... and better waves too!

Sunset beach is normally at the very bottom of the list of famous breaks that I would like to surf. Instead yesterday afternoon it was catching the forerunners of the new swell and it looked like perfect overhead fun lines. Watch the Vans contest online today and you'll maybe less perfect, but MUCH bigger Sunset beach. The one I wouldn't care to surf.

Here's a thing I figured out yesterday. This is the 3pm reading of Pauwela. The WNW swell was barely starting to show and it's always exciting (for my weird me, at least) to see any reading higher than 20s, so I got a kick out the that 25s one. But, why from 51 degrees?

Try to visualize the poor Pauwela buoy in the middle of the ocean being rocked 10 feet up and down every 10 seconds from waves coming from an ENE direction (that's the windswell). It's actually quite amazing that in that constant and very consistent oscillation and the roughness of the whole thing, the buoy was actually able to register such a much more subtle oscillation of .4 feet (less than 5 inches!) inconsistently happening every 25 seconds.

If you keep on visualizing the main 10f 9s oscillation, you will understand that the buoy has no chance to correctly detect the direction of underlying long period ground swell. I don't really know how the buoys do measure those things (and I'd love to investigate at one point), but it's pretty clear that in case of another much stronger swell in the water (like the windswell in this case), the buoy would get "overwhelmed" by it.

So the 25s energy was actually coming from somewhere around WNW (as we know), but because the buoy was heavily rocked up and down every 10 seconds along a ENE direction, that was the only direction it could detect. Can't describe this better with words, it's mental visualization thing.
Once the ground swell became big enough, the buoy started distinguish better the two swells and detecting both directions correctly.

Before we get into the exciting call for the day, a huge THANK YOU to blog readers Knox and Mike that stopped by the shop to give me a donation for supporting the blog.

5am significant buoy readings
South shore
1.6ft @ 13s from 174° (S)
That's the only indication of southerly energy I could find between Barbers and Lanai, because they are both getting quite "overwhelmed" by the WNW swell.

North shore
8.2ft @ 16s from 306° (WNW)

8.1ft @ 18s from 314° (NW)

9ft @ 10s from 80° (E)          
2.3ft @ 20s from 324° (NW)
Below is the graph of NW, Hanalei and Pauwela. I put arrows on the NW graph to show that the swell went from 2 to 8 feet in 12 hours. Not the fastest rise, but that's totally in line with the fact that the source was distant.
GP's rule of thumb for calculating the travel time from the NW buoy to Maui for NW swells is the following: 12h at 18s, 15h at 15s, 18s at 12s. It might not be exactly precise (preciseness seeking is nonsense in this matter), but it's symmetrical, easy to remember and it works... well, most times.

By applying that rule, I put two red arrows on the Pauwela graph to show where I think the two "equivalent" points of the graph should be. Even though it's not 8am yet, it's pretty clear that the reading at that time will be quite smaller than 8f. Where did all that energy go?
The answer is in the direction. Look at the Hanalei graph and readings. The swell gets there unblocked, doesn't have to refract upon anything and BUM, there you have it: 8f 18s!

Instead some of the energy that would have hit Pauwela if there weren't' any islands WNW of us, gets lost in refraction upon land points, reefs, or just shallower ocean depths. The longer the period, the more the energy of the swell travels deep under water, and the more it is then sensitive to how shallow the ocean gets when approaching a land. So even if the geometrical shadow line for Pauwela is around 305, a 20+ seconds swell will get blocked/refracted not necessarily by the emerged NE tips of Kauai, Oahu and Molokai, but by the shallower waters offshore of them. And that makes the shadow line of very long period ground swells completely different from what you can calculate by geometrically drawing a line between the emerged land points and the buoy.

Even knowing the bathymetry of the offshore waters, those shadow lines will be impossible to calculate exactly. But from a qualitative point of view, what we know is that they will be less west than the ones you get by considering only the emerged parts of the islands. For sake of clarity, I'm gonna force myself to throw some numbers out there. But they're completely made up, merely to help you guys to get rid of the doubts I believe you still have at this point.

Despite being one of the most crowded charts I've ever seen, the picture below might help visualize it better. I marked two bathymetry lines: a deeper one (B1 red color) and a made up shallower one (B2 blue color). I also drew their shadow lines for the Pauwela buoy: S1 in red and S2 in blue. The S3 in black is the shadow line of the emerged land and we know that to be 305 degrees.

I also drew a red triangle to indicate where the Pauwela buoy sits (red arrow with a P). There were already wave lines drew on it (and that was awfully convenient), so I just underlined them in red. Those are the wave lines of a swell that has a high enough period to feel the B1 bathymetry line.

Let's say that the waves of a swell with 25s period will be refracted at B1 depth. The wave lines in the picture show how they would refract and where. The related red S1 shadow line appears to be around 330. Please, don't take these numbers for true, once again it's just an example.
Let's also say that the waves of a swell with 20s period will be refracted at B2 depth. I didn't draw them, but you can imagine them. The related blue S2 shadow line appears to be around 320.


In other words, the higher the period, the more it's like the upstream islands become bigger and of a completely different shape. But that doesn't mean that the long period swells will get blocked more than the short period ones! It's actually the other way around. Part of the confusion stems from inappropriately use the word "shadow line". It's more a "start of refraction line". Let me confuse you guys even more, with another example.

Let's take two extremely different swells, a 25s and a 10s one, both 5f high. Let's give them the same directions and analyze three different cases. To simplify things, imagine there was only Molokai NW of us. We know that the geometrical shadow line from Pauwela to the NE tip of Molokai is 305.

Case 1) let's say both swells come from a direction of 345. It's fair to say that none of them will be affected much by Molokai. Resulting wave size at Hookipa: something like triple overhead + versus head high.

Case 2) both swells come from 290 instead. None of the 10s energy will hit the buoy/Hookipa. The swell won't be able to wrap around Molokai and will die right there, breaking against its beautiful cliffs. The 25s one instead will be able to wrap around and hit the buoy with whatever energy and direction it will have after the refraction. Probably still overhead at Hookipa but very inconsistent.

Case 3) both swells come from 305. That's the tricky case. The 10s swell will hit the buoy/Hookipa much more unaffected by the land and its shallower waters. The 25s one will instead feel the ocean bottom well offshore Molokai and as a result it will definitely be more effected by it. But because long period waves will shoal upon the reef much more than short period ones, the resulting waves at Hookipa will still be much bigger and more powerful. Maybe double overhead + versus shoulder high.
I apologize for the lengthy explanation.
So how big is the swell going to be in Maui at 8am? I don't exactly know and I don't particularly care about putting my precious few remaining neurons into guessing that. There's incredibly complicated mathematical models (like the Wave Watch III)  that do that. What I care about is to understand why and how things happen and that's what I just shared with you guys.
Said this, the Surfline forecast at 8am calls for 4.1f 18s from 319 +-9. Why 319? Because that forecast already takes into consideration NOT ONLY the loss of energy (4f instead of 8f in this case!) due to the refraction upon the upstream islands and reefs, BUT ALSO the change in the direction after the refraction.
Is that going to be enough for the Honolua contest to be run today? I think it will. But we'll find out officially in the 7.30am morning show starting in.. 45 minutes! Sorry for the late call, but it took me some time to write all that explanation.

Current wind map shows:
- a strong but distant fetch in the Kamchatka corner
- the windswell fetch
- a weak south fetch. I've been circling some kind of out of season fetches down there in the last week or so, and that is keeping the south shore from going completely flat, but that is about to end soon. So enjoy another week of small southerly energy, if that is your type of waves, because they will go into hibernation soon.

NAM3km map at noon shows moderate easterly trades.

PS. I put this post under the "wave period" and "refraction" labels for future references.

Thursday, December 01, 2016

12 1 16 morning call

Couple of session for me yesterday: the morning one in conditions that I over scored from the cliff (a 1 was too high), the sunset one was in classic November 2016 conditions with 20 knots of wind... not in the gusts though, steady!

What a horrible month November has been from the surfing point of view. Only one week of no wind at the beginning of the it (when the Aloha Classic had to be put on hold) and then it was always blowing strong.
Some windsurfers obviously enjoyed that, this is yesterday's conditions at Hookipa. Photo by Jimmie Hepp from this gallery.

Before we get into what's on offer today, let's see how the start of December is going to look like.
The windguru table below makes me take a big sigh of relief. Today is the last day of strong trades, tomorrow lighter and sideoff, and then a lovely strip of days with variable winds that might finally pump up a bit the morning rating for the surfing conditions at Hookipa. I see the potential to finally reach the excellent range.

Don't forget it's a la Nina winter though. Below is the wind map forecasted (by the GFS model in the Windity graphical representation) for Dec 6. As you can see, it's really not a typical winter configuration at all. The north pacific is still completely dominated by two high pressures, we're just going to be temporarily lucky to be right in the middle of the transition between the two.
Look how high the low pressure will be forced to be and that is not conducive to the usual Hawaiian big winter surf. I don't care, as long as it's clean, I'll take any size surf and I expressed my excitement on the map as well.

5am significant buoy readings
South shore

1.4ft @ 11s from 220° (SW)
0.9ft @ 15s from 198° (SSW)
2.2ft @ 11s from 211° (SW)
1.5ft @ 15s from 184° (S)

Both Lanai and Barbers show the fading 11s energy of the previous small south swell. They also show the 15s energy of a new swell that arrived yesterday, but the size is marginal. Check the webcam before going.
North shore
7.4ft @ 9s from 68° (ENE)
No sign of tomorrow's NW swell at any of the buoys yet (even though the NW one tends not to show the small long period readings, I noticed). Despite that, the NOAA is calling for Oahu:" 7 to 10 feet this afternoon, then to 10 to 15 feet late tonight".
They're probably basing that more on the models output than on the buoy readings. I'm just going to say that in Maui there should be no sign at all of that swell all day today. That is confirmed by the Surfline Maui north shore forecast below. In other words, windswell is all we have on offer on the north shore today.

Here's my outlook on the girls' contest at Honolua. And by doing that, I'm going to spend a few more words on my favorite wave forecast page, since I noticed some of the readers were still kinda confused about it. If you want a longer, more detailed explanation, please read this post.

First, here's how to get to it: click link. n.15 on my blog, scroll down a tiny bit, then click on the "offshore swells" tab. If the graph doesn't show on your Internet Explorer (it doesn't on mine), try with Firefox or Chrome. If this page is not available on the surfline app, screw the app and bookmark the page on your phone.

Once you're on that page, if you put the mouse on top of any of the arrows, you'll see size, period and direction. For example, the 8am arrow on Friday gives: 4.1ft 18s from 319 +- 9. That's what the wave forecasting models they use (probably the ww3 plus whatever customization they put in it, if any) predicts to be in the OFFSHORE MAUI WATERS at that time of the day. I find it extremely reliable and often matching exactly what is then recorded by the Pauwela buoy.
Note: it's for Maui offshore waters. That means that it already takes into account all the direction and size changes due to eventual refraction upon the other islands.

The +- 9 degrees is the range of direction they think the swell is going to have. That means that most of the energy will come from 319 degrees, but there might be energy (read sets) from a range of directions that goes from 310 to 328. That will never be exactly precise, but it's a good indication of how wide the directional spectrum of a swell will be.

The 8am reading for Saturday morning is 6f 15s from 313 +- 10 degrees and that reflect the fact that the fetch didn't move east like they normally do, but it was forced a bit south by the block of the high pressure. I pointed that out in the previous 4 days calls in the "current wind map" section.

Now that we got this key information, that's when the local knowledge comes into place.
From this post, we know that 319 is an unblocked direction for Hookipa. How big are the waves going to be over there? 4f 18s from 319 can easily produce double overhead sets, in my opinion.

From the same post, we also know that the Molokai shadow line for Honolua is 335, so even the eventually more northerly sets coming from the 328 side of the directional spectrum will be blocked. 

But it's not going to be flat though. Waves have the ability to refract around land points and the bigger the size and the longer the period of the swell, the better they do that. I talk about refraction in these two posts under the "refraction" label.

How big are the waves going to be at the Bay then? Well, I live on the north shore and don't know the Bay well at all, so I don't exactly know. But I'm gonna guess that they will be at least head high or more when the set arrives. The problem is that only the biggest and more northerly sets will manage to wrap around Molokai and so the frequency of arrivals will be low. Possibly even painfully low.

Friday and Saturday are the last two days of their waiting period. Are they going to wait there and check if the swells is big/consistent enough? What if it isn't? How quickly can they move the whole production thing to Pavillions?

If they want to be safe from the size of the waves point of view, they should take a decision today and move it to Hookipa for a Friday morning start.
From the quality of the waves and economical point of view (I imagine moving to another site to be very expensive) they should wait until Friday morning at the Bay (but then it might be too late to move).

We shall see.

** little update after having seen the morning show. They have a total of 16 heats left to run. That can be done in 8h, just one day. The best call will be to be at Honolua tomorrow morning to check the conditions and if it's a no go, they can still move the whole thing at Hookipa on Saturday. **

Current wind map shows:
- a NW fetch (this is the remnant of the one responsible for Friday's swell)
- the windswell fetch
- a weak south fetch

NAM3km map at noon shows the usual strong trades also for today.

Wednesday, November 30, 2016

7am Hookipa still has head high windswell peaks plus the occasional nw set. Bit windy, very poor shape. I don't care what Felipe says, this is barely a 1 out of 10.

11 30 16 morning call

Couple of sessions for me yesterday, one of which was with the foil, so I'm gonna talk about it in detail. So skip to the buoy readings if you don't care about foiling and just want to read the call.

So far my only experience with a foil was with on an SUP board being towed behind a boat. I only tried like 4-5 pulls and didn't have much success at all.

Yesterday I had the same board/foil, but I tried to catch small waves on the south shore. Let me tell you straight one thing: it was still difficult, but a lot easier than behind the boat.
Here's what you need to know to understand that. Other than one water skiing session when I was 15, my experience at being towed by a boat was none. So, being towed felt like a strange feeling all the times, even before the foil came up. Plus there was the awkwardness of having to hang on a rope that is pulling you forward, the noise of the engines, the weird bubbles left by them, a bunch of friends on the boat looking at you and overall I didn't have much fun at all, to be honest with you.

Instead while catching a gentle roller on the south shore, until the foil came up I was in extremely familiar territory. I was all ready in perfect stance and confident that I knew how to do that. No noise, no fumes, no weird bubbles, no distractions, all by myself. And even though I was going way slower than behind the boat, I was so in control that I could decide to push on the back foot to let the foil come up. And after that I managed to shift my weight on the front foot to bring it back down.

I only caught 4-5 waves and obviously I did wipe out without control on most of them, but I managed to stay away from the foil. The possibility of an impact with it is there though. Fortunately the wave SUP GoFoil (Alex Aguera design, made by Go Foil for Starboard) is pretty blunt, it might not cut you, but it'll still hurt you. Even the wipeouts seemed a less dangerous than the ones I experienced behind the boat though, thanks to the slower speed at which they happened.

A key factor in the learning process is to choose the right spot. Obviously you need enough water for the foil, so avoid shallow spots and low tides. The spot I was out seemed deep enough with something like a foot of tide, but I still managed to brush the bottom while paddling out.
After I hit the bottom and put some scratches on the foil, I paddled back in and waited for a higher tide. Which obviously came a couple of hours later, but it completely killed the small waves.

The thing is that you need some waves too and yesterday there were some, but they were tiny. Which means that they were breaking very close to shore. Ideally you want to have a couple of feet of swells in the water, high tide, no wind and all those waves on the lahaina side of Thousand peaks can become a perfect spot where to practice. I know, that doesn't happen very often because of the wind, that's when you can pick a spot between Launiupoko and Puamana. I can see the Cove in Kihei as a good spot too at high tide, but please make sure you pick a spot with nobody else around (good luck!).

The waves need to be big enough that you can catch it with your SUP. The foil doesn't come into play until you catch the wave, because only after you're going fast enough that you can make it come up. And, once again, that is what made yesterday's experience relatively easy and not as stranger. Until you have the two rails of the board touching the water, even if the foil is lifting most of the board and it's just the tail touching the water, you are still in familiar territory. As soon as those rails don't touch the water anymore, it's like someone suddenly took from you the crutches that you didn't even know you had! And that's when the new sport starts, I'd say.

That's when it becomes extremely critical to keep your weight centered on the center line. If you shift it either tow or heel side, you're going down for sure, because the thing reacts much quicker than a regular board. Of course, you got no crutches anymore! On your first waves, you want to focus on going straight and keeping the foil leveled. Learn how to make it go up and down by shifting the weight back and front. Which is what Kai does when he pumps the thing. I was able to do a little bit of that yesterday and that's why I consider it a successful session. Much better than behind the boat, at least.

Did I learn how to foil? Of course not, but I made significant progress. Once again, I only had 4-5 waves and than the conditions disappeared. Finding the right conditions, might easily be the factor that slows down your learning, that's the feeling I have.

Here's two applications of the foil that attract me:
1) surfing low quality small mushy waves (pretty much like every summer afternoon in Lahaina as soon as the onshore flow starts)
2) downwinders

I don't see myself doing this on a good wave, in other words I don't see this activity in possible competition with regular surfing. Check the video below for example.
It starts with Kai riding a perfect foil wave on the inside of Namotu. Then it switches a beautiful fun size wave at Cloudbreak, Kai surfs it lamely compared to what he could have done on a high performance shortboard, kicks out of it way too early because he wanted to go around Jace who is filming in the water, pumps his wave towards the wave out the back, grabs that one and surfs it lamely again.
It looks cool at first, but in my opinion that was a shameful waste of a beautiful wave. Two, actually.
Then it goes back to what I think it's the perfect wave for foiling. A wave that isn't even breaking or is low quality enough that you would not be surfing it otherwise.

And here's another video of a downwinder by Kai. Doesn't matter (I think) if you start prone or with the paddle on a SUP board, as long as you can get the foil up and keep it there and do what he does, I think it should be fun. To keep it flying with small windswell waves, you need some wind off your back, that's for sure. And if the wind dies, it will be easier to continue your slow downwind paddle on a SUP than on a 5.6 shortboard, that's for sure too.

I also don't think you want to learn how to foil on a downwind run right away. I see it much easier to learn on small south shore waves first (and Alex Aguera agrees with that) and THEN putting your skills out there in the middle of the ocean and trying a downwinder.
Problem is that the foil for a downwinder appears to be different than a foil for waves (wider for more lift at slow speed and less maneuverable), so you might have to get two foils for each of those two applications I just mentioned. It's too early in the sport for these details. At the moment we only have the wave SUP foil at Hi-Tech, but soon we'll receive the downwind ones (I'll let you guys know here for sure).
I might have to start by buying a wave foil (not sure my boss will lend me his anymore after the small scratches I put!). They are expensive (I think they retail for $1650 or something like that). But just like at the very beginning of SUP boards back in 2004/2005, it doesn't matter what you bought, the demand was so high that you could always resell your board at any time.

The sport is not going to be as big as SUP surfing. Not a chance. But there will still be enough demand and very limited offerings, at least for a while. So get yourself a foil before we run out of them. Your biggest problem will be to decide what board to convert with the installation of the tuttle box...

5am significant buoy readings
South shore

1.4ft @ 13s from 229° (SW)
1.2ft @ 3s from 3° (N)
1.1ft @ 7s from 159° (SSE)
0.5ft @ 18s from 215° (SW)

Small southerly energy at the Lanai buoy (and none at Barbers), with a lovely half foot 18s that Pat Caldwell totally called for in his table. Check the webcam and see if you like it!

North shore
6.2ft @ 10s from 85° (E)           
5.1ft @ 8s from 76° (ENE)
3.4ft @ 13s from 338° (NNW)

No NW energy on any other buoys tell me that whatever is leftover in the water is not going to be particularly significant. So it's going to be mostly windswell with the occasional NW set and it could be one of smallest/roughest  day we've see in a while.

Current wind map shows a wide NW fetch (latest Surfline forecast calls for 7f 16s Friday afternoon), the windswell one and a weak one down under.
MC2km map at noon shows the usual lot of wind. Again, it might end up being even stronger if the sun shines or much weaker if it's rainy all day (like yesterday).