Saturday, July 21, 2018

Saturday 7 21 18 morning call

A SUP and a longboard session for me yesterday. Here's a uncle charging a fun section at Uluwalu.

3am significant buoy readings
South shore
2.5ft @ 14s from 161° (SSE)

2.4ft @ 14s from 162° (SSE)

2.9ft @ 14s from 197° (SSW)

2.5ft @ 15s from 180° (S)
0.5ft @ 25s from 191° (SSW)

2.3ft @ 15s from 192° (SSW)

Surfline took their time, but they did add the Lanai buoy to their fabulous page (which by itself is worth the subscription, imo) in which they break down the energy of all the different swells hitting a buoy. As you noticed, I didn't even bother checking it on the NOAA page in the meantime, as I consider that data not only empty of significance, but also deceiving. Link n.11, which is now subscribers only accessible.

Anyway, south swell went down 1s, but still solid. Yesterday late morning there were head high sets at Thousand Peaks, sorry if I didn't have the time to upload the report, but I was pretty busy as usual.
Here's how Pat Caldwell describes the source of this energy and its direction: The source was an area of seas greater than 30 feet to the SSE of New Zealand 7/12 with aim at the Americas. A great circle line from Hawaii to the source is 190 degrees. However, the angular spreading causes the swell direction upon arrival in Hawaii to have more straight south component.
Here's the map of the 12, for your convenience. As you can see, I circled the fetch in blue since it wasn't aimed straight at us. I also drew the "cock roach antennas" with a slight bend, because that's how the swells spread angularly when they propagate after being generated by a fetch of strong winds.

Uncle Pat continues his delightful analysis with: The next austral, mid latitude low pressure 7/13-14 strengthened and gained more northward aim to the fetch as it reached the eastern edge of the Hawaii swell window south of French Polynesia. The near miss makes for greater error bars on the local surf estimate.
Below are the maps of July 13-14, I personally didn't see much on the first one, but don't forget it's only a midnight sample.

Here's the final bit of the analysis: The final austral source 7/15-17 was the strongest and had the best aim towards Hawaii at the eastern edge of the Hawaii swell window. It had a wide area of seas over 30 feet with peak seas to 40 feet. The system moved steadily east away from the Hawaii swell window.
Extra-long wave periods of 20-25 seconds are predicted to slowly fill in locally on Saturday, making for inconsistent sets. It should be filled in by Sunday from 165-185 degrees to levels above average, peak Sunday night, and slowly drop to average levels from the same direction by Tuesday. Background level conditions are expected to take over by Wednesday.

Here's the maps of July 15 and 16. I don't particularly agree that the last fetch had the best aim at us (at least not in that midnight snapshot), but it had the strongest wind and guess what, Barbers is sensing half a foot 25s, just like uncle Pat (and the WW3 model) said. Gonna be interesting to spot those sets in the midst of the 14-15s ones, but that applies to wave weirdos like me. For most of the surfers, what counts is that there will be waves, coming out of... nowhere!

North shore
4.6ft @ 8s from 76° (ENE)

Small windswell, but at least from a decent direction. Wondering what's the orientation of the north shore of Maui? The answer is in one of the many maps of the epic post Buoys to Maui travel times and Maui's shadow lines: 65 degrees.

Hookipa has a slightly better exposure to the windswell: 68 degrees. I believe today it's going to be small over there, but not flat.

Wind map at noon. Good stuff for both the down wind Maliko race and the windsurfing Kanaha Race.

North Pacific offers two distinct windswell fetches, the most remote of which will generate the higher period waves.

Just a weak fetch in the Tasman Sea on offer in the Southern Pacific. Much better than the nothingness of the past three days.

Morning sky.

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