Tuesday, January 10, 2017

1 10 17 morning call

Yesterday was a gorgeous day of surfing on Maui's north shore. I had two session for a total of 4.5 hours... it was so fun, I just couldn't get out of the water.

Here's a few shots I took in between sessions. Very smooth faces were the norm.

Kai Lenny in a Currenish bottom turn.

Blog author in a very non Currenish bottom turn

Greek/Swedish blog reader enjoys the view of a beautiful wall.

I'm going left and the board is totally facing right: that was a proper cut back!

5am significant buoy readings
South shore

0.8ft @ 18s from 194° (SSW)
0.7ft @ 15s from 204° (SSW)

1ft @ 15s from 192° (SSW)
0.9ft @ 18s from 180° (S)
Lovely couple of long period readings at both the local south facing buoys. South shore is supposed to slowly come up today. It shouldn't be a surprise for you guys, since I've been highlighting the fetches every morning. Notice how the 15s one is a little more west at Lanai than the 18s one and it's vice versa at the Barbers buoy. I could go dig the wind map of a week ago to find out which one was generated more west, but it would be a complete waste of time. It is what it is and this example teaches us not to get too fixated on the numbers at the buoys in general.
Check the webcams before going, that's what you want to do instead.

North shore
4.8ft @ 13s from 20° (NNE)           

3.7ft @ 10s from 36° (NE)           
1.4ft @ 15s from 18° (NNE)
Old 9-10s period swell is dying, new 13-15s period swell is rising.  Below is the graphs of the only two buoys we care about with this direction. The N one is on the left and Pauwela is on the right where I drew what I think the two swells will do today. The blue shorter period one will keep decreasing, the red longer period one will keep increasing up to 4f 14s sometimes this afternoon.
The morning will be very small, with just a few occasional sets from the new swell breaking.
Seen the amount of energy that we've received from the N to the NE in the last two weeks, here's a discussion that I should have done... two weeks ago! Better too late than never, here's the travel times from the N buoy to Maui, as you've never seen them before! (that's because I don't think anybody ever calculated them and published online).

The N buoy is 212 nm out at a 42 degrees angle. Here's the travel times for a NE swell coming from exactly 42 degrees:

  P               S                T               GP's
10s  =  15.6   =  13.5  =  13    
11s  =  17.16  =  12.3  =  12 
12s  =  18.72  =  11.3  =  11
13s  =  20.29  =  10.5  =  10
14s  =  21.84  =   9.7  =  -
15s  =  23.4   =   9.0  =  -
16s  =  24.96  =   8.5  =  8
17s  =  26.52  =   8.0  =  -
18s  =  28.08  =   7.5  =  -
19s  =  29.64  =   7.1  =  -
20s  =  31.2   =   6.8  =  -
21s  =  32.76  =   6.5  =  -
22s  =  34.32  =   6.2  =  -
23s  =  35.88  =   5.9  =  -
24s  =  37.44  =   5.7  =  -
25s  =  39     =   5.4  =  -

- P is the period
- S is the speed at which swells travel  in knots (nmph)
- T is the time to cover the 212 nm that separate the N buoy from Maui
- GP's is the approximation of that time to provide a rule of thumb that is easy to remember. In this case it could be 10h at 13s and viceversa (with valid interpolation in between) and then you have to remember that 16s will take half of that numbers in hours (8). Most swells coming from the NE don't have elevated periods anyway.

Every other direction, either more north or more east will take less time to get here. BUT, it will not be exactly the same energy that's hitting the swell though (that should be more clear in the next picture below). Here's the travel time for a straight north swell, for example.

20sec--30kts--5 h

17sec--26kts--5.8 hrs

14sec--21kts--7.2 hrs

11sec--17kts--9 hrs

Today's swell is coming from 12 degrees and at 14s, the travel time is 7.6 hours. BUT, as I was saying before, that energy that is hitting the N buoy will miss Maui to the east. 7.6 hours later, we're gonna get the energy that would hit a buoy sitting where I put the question mark on the map. Is that energy going to be exactly what is at the N buoy at the same time? Of course not and there's no way to find out the difference which, seen the relatively close distance between the two points, is not going to be too big anyway. Once again, don't get too fixated on the numbers, you see how many approximations there are?
This post is labeled "N buoy to Maui travelling times" for easy future access through the labels section of this blog.

Current wind map shows:
1) the big and strong fetch that is stirring plenty waters in the NW corner. Updated Surfline forecast calls for a peak at 13f 16s from 309 Friday night. The windiest spot inside the fetch I could find was 59 knots. From that position, we will definitely get some big waves (definitely outer reefs and Jaws kinda stuff) on the north shore. My comment about being too west and possibly firing the Kihei coast was referred to the position this fetch had yesterday. Could still be possible. Check how west the very bottom of the fetch is.
2) a much smaller but closer and less blocked fetch. 6f 15s from 316 mid day Thursday.
3) that NNE fetch just doesn't wonna die, does it? Hang in there brother, the bullies from the NW are about to take over, but someone in Maui absolutely loved what you did for us.
Nothing south, so I went for a little more closeup map.

NAM3km map at 7am shows again ideal light offshore condition for the dawn patrollers.

NAM3km map at noon shows possible sailing conditions up the coast, but:
1) probably not at Hookipa because of the 10 men rule
2) only if your slog and surf skills are REALLY good

Looks a little better in the 4pm MC2km map, but you still need to be good at slogging and surfing.
Best way to learn how to do that: get your self a big/wide wave board. You'll see how much your light wind skills will improve. And how much cleaner the wave faces are when the wind is light.
Planing might be the best feeling most windsurfers ever experienced the first time it happened to them (I'm never gonna forget my first time...), but it's SO overrated when it comes down to down the line wave riding. A total disaster, really.

No comments: