Saturday, April 18, 2020

Saturday 4 18 20 morning call

Thanks to blog reader Javier for his donation.

This is Hookipa yesterday morning.


Maui residents Manu and Carine Camboulives posted a new short film, I'm always happy to share them.


4am significant buoy readings and discussion.
South shore
Barbers
1ft @ 18s from 196° (SSW)

Lanai
1.2ft @ 18s from 196° (SSW)

Lovely 18s small readings at the buoys from the Tasman Sea swell we discussed yesterday. Check the Lahaina webcam if interested, for size, conditions and consistency, that side might be a good option for the morning (but it looks painfully slow), while waiting for the new WNW swell (see below) to pick up on the north shore.

North shore
NW101
4.1ft @ 17s from 302° (WNW)

Hanalei
1.4ft @ 18s from 310° (WNW)

Waimea
1.5ft @ 11s from 305° (WNW)
0.9ft @ 20s from 297° (WNW)

Pauwela
3.4ft @ 9s from 72° (ENE)
1.9ft @ 11s from 319° (NW)

The first WNW swell is almost gone (2ft 11s) while the second is on its heels.

Here's how Pat Caldwell described the evolution of the fetch:
The second in the wintry series formed 4/13 east of Japan. The location was even further south than the first system. This placed gales to severe gales, with pockets to storm-force over a fetch of 280-310 degree band as the system moved slowly ENE 4/13-15. The system occluded early 4/15 and slowly weakened as the system moved to the Aleutians on the Date Line by early Friday 4/17. During 4/15-17, primary fetch is over the 305-320 degree band with mostly as well more aim to the NE of Hawaii.
The largest surf is expected from the early stages while the ocean surface winds were strongest and grew seas within 30-35 feet beyond 2100 nm away over the 285-310 degree band.

Below is the collage of the fetches maps of April 13 through 17. The fetch is indicated by the red arrow and you can see how its position in the first days of wave generation is definitely not favorable for Maui (185-310).



Below are the graphs of NW, Hanalei and Pauwela, together with the Surfline forecast. The red circles indicate the new swell. On the post Buoys to Maui travel times and Maui's shadow lines you can see that at 18s it takes 14h from the NW buoy to Maui and 7h from Hanalei. I drew a red dotted line consequently, trying to account for the reduction of size due to the shadowing of the upstream islands. I'm going to guess around 2-3ft 17-18s by sunset. The Surfline forecast is the usual 12h late.
On the same post, you can also learn that the shadow line for west swells for Kihei is 173, so partially blocked too, but with such long period, it is possible that there will be some waves over there too at sunset.

Hookipa will be very small to start with and only in the afternoon the sets of the new swell will start to be visible. Possibly well overhead but inconsistent at sunset. Probably flat down the coast instead.



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):


South Pacific fetches map (about 7 days travel time from east of New Zealand):


Morning sky.

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