Saturday, July 13, 2019

Saturday 7 13 19 morning call

No shots of the day, this is a beautiful sunrise in Tavarua, Photo by @fijichili.

This weekend at the harbor there is an HSA contest. This is the tentative schedule for both days.

3am significant buoy readings
South shore
1.9ft @ 16s from 185° (S)                        
1.5ft @ 14s from 190° (S)
2.2ft @ 17s from 188° (S)                        
1.9ft @ 14s from 196° (SSW)

Perplexing readings at the buoys. I don't see the 20+ seconds readings of the second and much bigger pulse of this swell that were suggested by the readings registered by the Samoa buoy that I posted a few days ago. They're either:
1) masked by the 17s energy of yesterday's first pulse and will appear only later today
2) they never really showed up as 20+ and they are already down to 17s, while the first pulse is already down to the 14s energy that is also reported, which would mean that this swell is going to be a lot smaller than predicted.
What Pat Caldwell said yesterday is in line with the first hypothesis and my gut feelings tell that that is the case too. Those 8ft 18s at the Samoa on Wednesday must still be on the way.

A captured fetch, meaning growing seas aimed at Hawaii moving at nearly the same speed as the associated weather pattern producing the winds, set up from near 60S, 160E 7/6 and stretched to near 40S, 170W, over 1500 nm by mid 7/7. A wide area of severe gales with small pockets to storm-force winds grew seas within 30-40 feet. The aim was smack dab at Hawaii within the 185-200 degree band. The associated low pressure dropped to 937 mb early 7/7. The system slowly moved east 7/8-9 as winds weakened and aimed less at Hawaii.
The PacIOOS/CDIP American Samoa buoy registered the largest amount of energy in the 14-22s band aimed at Hawaii so far this south swell season 2019 starting late 7/10 into 7/11. There were some sharp peaks in the energy well above the mean energy over that roughly 24 hour period in the 16-22s bands. Those peaks represent exceptionally high surf potential for short-lived bursts.
The onset stage locally is due Friday night to Saturday near sundown with extra-long wave periods of 18-22 centered from 190 degrees. Inconsistent sets are expected above average. Heights should ramp up sharply Saturday near sundown into Sunday morning.
The heights in the table above refer to the more energetic envelopes, or spells with more frequent larger sets, for the zones of high refraction, which is where the largest breakers occur. Keep in mind the larger sets of the more active envelops represent a small percent of the overall time. The mostly frequently seen breakers are typically much lower. The low spells can give a false sense of security within the surf zone and lead one into potential harm when the fast-moving, larger sets arrive.
The event is predicted to peak late Sunday. Such remote, large sources have slowly changing surf size locally. Heights should remain well above average Monday from the same direction. The slowly declining surf should hold at least to near average into Wednesday.

Below is the collage of the maps of July 6 to 9. The fetch he's referring to is the one indicated by the red arrow. He didn't even mention the other big one indicated by the blue arrow which, to be honest, I'm not even sure it was all oriented towards us, because the lower part wasn't covered by the great ray circle map and the curvature induced distortion is pretty extreme down there.

The offshore swell Surfline forecast below is based on the WW3 model. Also this one is in line with the first hypothesis, as the first pulse is the purple line and the second on is the blue line, which is predicted to peak only late tomorrow.

So I believe the really big stuff is still not showing at the buoys and will do so later today. Either way, check the Lahaina webcam for size and conditions before going.

North shore
3.5ft @ 5s from 90° (E)
2.5ft @ 7s from 104° (ESE)
2.1ft @ 9s from 91° (E)

1.8ft @ 9s from 331° (NNW)

1.4ft @ 9s from 315° (NW)

NW swell down to 9s and declining and with a pretty low and straight east windswell, Hookipa should be pretty small to start with and trending to summer flatness during the day.

Nothing of relevance in the North Pacific.

South Pacific has a couple of SSW and SSE fetches.

Morning sky.

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