Saturday, October 5, 2024

My Observation Beats Your Forecast

If one person says it’s raining and another says it’s not raining then the journalist should look out the window and report the truth. Unknown.

Stupidly, I had packed my lovely Jantex wing blade away in my front hatch instead of strapping it to the back deck. I do this simply to avoid washing the paddle after each trip. You might think that if the paddle has simply sat on the back deck unused it won’t need washing with fresh water, but you’d be wrong because salt gradually gets encrusted on the shaft and you end up with a paddle that will not go together when you need it most. But, if you need your spare paddle, what good is it stored away in a day hatch?




This is not the first time I have wanted to switch paddles on the water and been prevented from doing so easily because my spare paddle is safely stored below the hatch. You’d think I’d learn! One November day on a trip across to North Head with Quick Nick, I was, of course, paddling with my wing blade while my flat blade was safely stowed away in a dry hatch, but the adjustment on my wing blade was loose (we thought it was loose but it turns out when more closely examined at home, the joiner had actually worn out and I needed a new one) which meant the two halves of my paddle spun about as I was paddling resulting in many, many missed strokes where missing strokes was not only very slow but almost capsize material. I was not a happy paddler and I got a lecture from Quick Nick about having my spare paddle accessible.


My HR after switching to my wing blade


This time, I wanted to switch from my flat blade to my wing blade because the wind was getting up and I’m much more efficient in windy conditions with a wing blade. Somehow, despite the forecast I seemed to be the only person expecting windy conditions. Dan John has an expression “what do YOU mean by XYZ?” and I always think about that when among a group of three or four people there are three or four widely varying forecasts. It seems like only one person can be right; there should be only one forecast, but a lot of people use apps (such as Willy Weather) which pull their forecast from a variety of secondary sources.



Willy Weather forecast, 10 knots max


Willy Weather for North Head for example (an app that paddlers commonly use but which I make no bones about NOT liking), claims to use BOM data for its wind forecast, which is inexplicable to me because the Willy Weather wind forecast rarely matches the BOM marine forecast. This makes me think there is some algorithm in the app which adjusts the forecast. I dislike these algorithms (common as they are) because it’s impossible to know what the algorithm is and it turns out that humans are much better at this kind of thing than machines. Humans ARE pattern recognition machines, it’s how we evolved.





On this day, for example, the BOM forecast is shown above. The synopsis – a feature of the weather forecast which is surprisingly hard to get in Australia – predicts cold fronts and fresh westerly winds. Around Batemans Bay, westerly winds can be fresh indeed as they tend to funnel down the Clyde River Valley and conditions can get surprisingly rough where wind and tide collide. The BOM marine forecast has an increasing sea, and, off-shore (a flexible definition at best) winds up to 20 knots. Willy Weather predicts winds to just around 10 knots from the west. Twenty knots might only be twice 10 knots, but for the paddler, the effect is more than doubled as making progress into a 20 knot headwind – offshore no less – while not nearly impossible, takes some effort. I admit to being always leery of off-shore winds as the margin for error shrinks rapidly.





Weather forecasts aside, I think my pattern recognition software must have been firing because I was expecting it to get windy. I even tried to get one of the paddlers to make a bet with me but he refused. I love betting on these things. It’s my downfall. Captain Bivouac once took away all my hard earned Bivouac Points when I lost a bet with him while we were out on an eight day ski traverse. I had managed to amass several hundred Bivouac Points which would have kept my site membership active for decades and I lost them all in one rash bet! But back to the weather around Batemans Bay. Sunday was forecast to be at least 10 degrees hotter than Saturday. Whenever the air temperature changes by 10 or so degrees between one day and the next (hot or cold), we have windy conditions. It makes sense, the hot air has to come from somewhere and that somewhere is far enough away that you can lay money on windy conditions. That is, if you can coerce someone into betting with you.

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