Tuesday, February 07, 2017

Tuesday 2 7 17 morning call

Just one session for me yesterday morning, the Kona was really howling, but of course there were spots that were surfable. Later in the day, some very skilled windsurfers challenged the radical conditions at Lanes, here's Morgan Noireaux in a photo by Jimmie Hepp from this gallery.

Kai for the ladies.

This one is from my soul Superbowl session (I'll call it Supersoul) Sunday afternoon at Hookipa, photo by Andy Bridge.

4am significant buoy readings
South shore

All west wrap at the buoys, check the webcams to see how the windswell left by 2 days of strong Kona looks like.

North shore
NW101 (3am)
9.2ft @ 10s from 318° (NW)
7.2ft @ 13s from 316° (NW)
4.6ft @ 6s from 300° (WNW)

4.9ft @ 14s from 304° (WNW)           
3.8ft @ 9s from 305° (WNW)
2.9ft @ 7s from 293° (WNW)
2.7ft @ 12s from 314° (NW)

4.6ft @ 15s from 325° (NW)
2.6ft @ 10s from 345° (NNW)

The Waimea readings show pretty clearly what kind of surf we should expect today. And if that's not clear enough, here's how Pat Caldwell explains it:

It should hence look a lot different than how it looked at noon yesterday. Scroll down to yesterday's mid day beach report if you haven't seen it yet. That might be the best picture ever taken by my very average phone camera. The swell building yesterday was generated by a remote source and you can tell just by looking at those gorgeous lines.

The one on tap today is generated much closer and the passage of the front will accompany it with onshore winds at one point (I'll talk about that later in this post). Below is the Surfline forecast for the next three days (what you get at link n.8 without a subscription), and the three points I wrote the size in feet for are: 2pm, 8pm and 2am and the period for all of them is 14s.

Current wind map shows:
1) another wide WNW fetch on the conveyor belt
2) the very close NW fetch responsible for today's swell

Waiting for the MC2km maps to get updated, I wasted my time trying to interpret the NAM3km maps. This first one is the 6am one (or more precisely the 4 to 7 one, the models outputs are 3 hours apart). As you can see the wind was predicted to be onshore already.

This one is the 7am (or more precisely, the 7 to 10 one) and the wind is very light SW instead. According to this model, the wind should do this switch back and forth one more time, before getting definitely onshore in the afternoon.

I actually have seen it doing that quite a few times. Some fronts are not a one compact line of clouds and instead you can identify multiple "mini-fronts" within a front that will create that multiple switch of the wind. This is often the case when we get hit by the very tail of the front. It's like down there the warm and the cold front haven't occluded completely just yet.

This situation is illustrated in the 5am satellite picture below. I circled in red a couple of mini-fronts that could create or have created that double wind switch (black arrows indicate the wind direction).
As of 5.45am, the Hookipa iWindsurf.com sensor is reading 6mph from SW, so the dawn patrol should be clean. Unless it really was onshore during the night, in which case the morning sickness might be in this case lethal. Stay tuned for the beach report for that.

Let's see what a more reliable model as the HRW (on which also the MC2km maps are based) predicts on the Windguru page. The switch of the wind should happen between 9 and 11am and conditions on the north shore should greatly deteriorate after that. Check the MC2km maps when updated, they are the best.

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