Tuesday, April 21, 2015

4 21 15 morning call

Gonna use this sequence to:
1) show that the early morning saw some small waves on south shore yesterday, but the swell slowly and steadily grew all day
2) show my SUP and longboard students how a sharp change of direction is achieved on a big board (this post labeled under "surfing technique").

The guy is lifting his back foot from a cruising position.

He moves it far back on the board. How far back depends on how sharp of a turn he wants to do. Notice also that the toes are in the middle of the board and that will make the hill go well on the side.
In backside turns you can't leverage on the front of the foot to push the rail in, so you have to place the hill well on the rail. Once again, how much on the rail depends on the radius of the turn you want to achieve.

Back foot is now planted in the perfect spot, he starts shifting some weight on it.

The back of the board is being sinked on the rail inside the turn. As a result, the nose sticks up. The guy is twisting his upper body towards the turn and he's looking at where he wants to go.

That's the moment of maximum pressure. Had he had the paddle on the inside of the turn, he would be leaning on it now. He could have switched side mid turn, but for such a small wave there was no need really.

 As he's coming out of the turn, he starts releasing some pressure so that he can get some speed again. In the next few shots, he will actually walk forward a bit.

And there we go, we got a longboarder too doing the same thing.

Wind map today only shows a almost insignificant fetch NW of us. No more fetched pointed at us down south.

Wind should be strong and gusty seen the easterly direction.

6.0ft @ 9s from 98° (E)
4.8ft @ 12s from 301° (WNW)
4.6ft @ 7s from 80° (E)

4.1ft @ 7s from 31° (NE)
3.4ft @ 11s from 339° (NNW)
1.4ft @ 16s from 267° (W)
1ft @ 5s from 28° (NNE)

6ft @ 7s from 74° (ENE)
5.9ft @ 9s from 82° (E)
1.7ft @ 3s from 83° (E)

Pretty decent NW reading at the NW buoy, nothing at the Pauwela, but I'm pretty sure there will be something more than just windswell at Hookipa today.

2.6ft @ 7s from 174° (S)
2.3ft @ 15s from 203° (SSW)
0.9ft @ 4s from 167° (SSE)

3.3ft @ 15s from 194° (SSW)
2.8ft @ 8s from 131° (SE)
2.7ft @ 9s from 131° (SE)
One foot difference between Barbers and Lanai is a lot and I don't know how to explain. Maui's south shore gets blocked by Kahoolawe a lot, but not Lanai. I've seen this often, and I'm gonna guess that Barbers is more sensitive than Lanai, but I've seen the other way around too.
What counts is that there is some energy in the water and it should be a pretty good day.
Below is the weather map of 7 days ago down south. As you can see, compared to the one I posted yesterday, the fetch is now just east of NZ and that's where you want it to be. Direction from there will be straight south for Maui and as usual the following factors will influence the height of the waves it will generate:
- wind speed
- width
- length
- fetch speed and direction. The only direction that will actually increase the wave size is when the fetch moves in the same direction of the winds it is made by. In this case it should move straight north. If it happens that it also moves at the same speed of the waves it generates, then it's called captured and that provides the maximum wave heights. Unfortunately, as we will see the next days (I'm gonna post the week old map for every day of this week), it won't do anything like that. Fetches down there like to move east. So in this case, the slower they move the better, so they keep building waves over the same area of sea.

What happened between yesterday and today ONE WEEK AGO is also beautifully explained by Pat Caldwell. Unfortunately he doesn't have the possibility of using the help of graphics and maps (why not, I don't really know), so he has to use a lot of words to describe it. But it's a great read. Thanks Pat!
Low pressure over New Zealand 4/11-12 placed gales in the Tasman sea. Swell from this source out of 208-220 degrees picked up locally Sunday 4/19. It should linger on Tuesday.
The low pressure area moved east 4/13-14 as a secondary low pressure cell from S of New Zealand merged into it, dropping central pressure to 955 mb near 50s, 170°W 4/14. A long, wide fetch of gales to severe gales grew seas to 30 feet with the head of the fetch about 3800 nm away. The system weakened as it moved slowly ENE 4/15-18.
The pacioos/cdip american samoa buoy showed a sharp rise in swell height 4/17. It remained elevated with a secondary maximum early on 4/19. Dominant periods were around 15 seconds through the period. With the 2200 nm travel distance and swell centered on 190 degrees, this would take 4 days to reach Hawaii.
Surf is expected to slowly increase late Monday through Tuesday, then remain at a quasi-maximum late Tuesday to early Thursday from 180-200 degrees at levels above the summer average. Heights should fall to near the summer average on Friday then gradually fall to summer background levels over the weekend from the same direction.
 Pat also told us so that the travel time for 15s swells is around 4 days from Samoa to Hawaii. It is probably 4 more days from the fetch to that buoy some maybe the total is 8 instead of the commonly known 7?
Graph below will help a bit, but the message here is that I'm never really sure how long the waves generated down there travelled to get here. But for sure they travelled a long time. That's why you don't want to miss them and if you catch them, you don't want to blow them!
Have a great day, and don't forget my golden rules for south swells. Unless is 4f 15 at the buoy, never ever under any circumstances get excited about a south swell in Maui!


Anonymous said...

I already know how to turn a SUP and longboard. Please no more surfing tips, I come here for the forcast info.

If I wanted to know how to surf, I'd hire a surf instructor.

R- said...

Yeah, I agree, stick with the forecast!

I think you are spot on with this strong wind killing the swell.. on both north and south swells..

Always good to get wet tho!


Mario said...

I agree, I'm used to getting through the forecast easy enough. But the surf tips are stupid. Why don't you go start a website on how to surf?