By the way, the sign I posted a couple of days ago was clearly a "non official" one, and today the ocean is still open. Someone posted it on the social media and it got a bit viral generating all kind of reactions, from "that's a privacy of our freedom!" to "it's about time to shut down the ocean!". It's a bit scary how powerful the social media has become, but what counts is that the message was a valid one and it seems that now people are more responsible and I didn't see as many families going to the beach with for a picnic like nothing was happening.
6am significant buoy readings and discussion.
1.9ft @ 15s from 311° (NW)
1.9ft @ 16s from 193° (SSW)
I was tempted to not post any readings, as there's no southerly energy, but it's a good example of how you need to interpret them. Barbers clearly shows that the 15s reading is from the long period NW swell and so you can deduce (also knowing that there wasn't any fetches down south a week ago) that also the 16s energy at Lanai buoy must be that wrap. In Lanai's case, the wrap is such that it appears from 193 degrees, and it might even be true at the buoy, but that doesn't mean that the same energy will make it to Lahaina. At this point, the thing to do to find out is to check the Lahaina webcam, if interested, for size, conditions and consistency (there's some waves but it's onshore because of the southerly flow).
5.3ft @ 8s from 1° (N)
3.6ft @ 8s from 50° (NE)
No bragging here, just teachings: yesterday (Monday morning) I wrote The first pulse of the closely generated NW swell went down quickly (as the history of the fetch would suggest), but already tomorrow a reinforcement of about 11-12s should arrive. That was exclusively based on the observation of the fetch, without checking any other source. Later in the afternoon, Pat Caldwell wrote:
The initial stages Saturday to Sunday locally 4/4-5 saw the largest breakers from the aforementioned low. Those higher breakers were generated during the onset phase of the low pressure occlusion with gales aimed just west of Hawaii 4/1-2. That fetch weakened into 4/3-4 with only fresh to strong breezes over a short fetch aimed at Hawaii within 300-330 degrees. Hence the sharp drop Sunday into Monday 4/5-6. Wait, it is not over yet.
ASCAT satellite 4/5 showed the surface winds over the aforementioned fetch aimed at Hawaii to strengthen a notch with some pockets to near gales and seas of 10-12 feet about 800 nm away. This shorter period energy should trend up the surf from 300-330 degrees locally Tuesday into Wednesday 4/7-8 with surf heights below the April average. The WNW to NW component of this short-period event is expected to drop Thursday 4/9 as the dominant energy swings to NNW.
That is to show that, as long as you've built some knowledge by doing that long enough, the observation of the fetches should immediately tell you what kind of swell we're going to get and when.
Now, you might want to grab your coffee here, as I put some time into the collage below and will put some more time into explaining it. We have the graphs of the four reported buoys and the Surfline forecast. Arrows color legenda:
blue: long period distantly generated WNW swell
red: short/medium period closely generated NW swell
black: short period closely generated ENE windswell.
The red circles indicate the rise of the second pulse of short/medium period closely generated NW swell, which started occurring around noon yesterday at the NW buoy. It shows a period of 10s. By applying GP's rule of thumb for the travelling time (16h @ 16s +/- 1h per 1s), we know that at 10s that takes 16+6=22h to get here, so it should start rising around 10am locally. As a matter of fact, at 6am there's no sign of such rise yet at Pauwela. The blue line in fact indicates the easterly windswell (see the direction in the lower part of the graph). The red dotted line shows my prediction of the rise which will be noticeable in the afternoon, with a possible light kona wind for good measure. The surfline forecast, as usual, is delayed by about 12h or more. Btw, I did email Surfline and they replied that they're gonna look into it. I'll keep you posted if they reply again.
Meanwhile, in the morning we have the long period energy of the distantly generated WNW swell (2.2ft 15s) and the 8s period easterly windswell (3.6ft). Hookipa will have relatively small waves (with very clean conditions seen the southerly flow of the wind) before the above mentioned increase in the afternoon. Overall, it should be another really good day of surfing over there.
Uff, that was a lot of work, I hope someone read the whole thing...
Wind map at noon (the other ones can be found at link n.-2 of GP's meteo websites list in the right column).
North Pacific fetches map (about 4 days travel time from the NW corner):
our beloved nearby low keep producing waves and shutting down the trades.
South Pacific fetches map (about 7 days travel time from east of New Zealand):
No fetches worth the red circle, but I put an arrow on cyclone Harold, which is about to hit Fiji.