We will all have our favourite weather app, won’t we?

Do you find that you look at more than one weather app to judge what the wind is going to be at your sailing venue? What rig shall we go out on?? Well, this article is aimed at you !!

I recall a few weeks ago at Datchet, Rob V telling me he had abandoned the BBC App as it was simply never right!! I have huge sympathy for that … but some days it does seem to be correct 🙂

Many years ago, we used to have an anemometer at the top of the slipway which told us exactly what was happening there at the moment, but there again it gave you a reading – not a forecast. Chipstead SC have a smashing online weather station at the side of the lake… but there again it’s not in the middle of the lake!! So what to do??

During lockdown, the main Datchet Club ran a Members’ Zoom tutorial on this subject. It turns out we have a meteorologist member in the main Club who hosted the session. Extremely interesting, it was.

Did you know that the world of weather forecasting is basically a wholesale-retail model? At the wholesale level, which is where all the data comes from, there are really only half a dozen suppliers of weather data worldwide. I think we were told that for using truly global data there are only two suppliers. These suppliers are currently at the level predicting wind in a 1km grid section… and trying get even finer resolution. Huge compute power is the limiting factor.

The other suppliers are basically the lower cost alternatives. As I recall, UK Met Office is one of the big players. You may recall a kerfuffle a few years ago when the BBC decided to stop using the Met Office data and signed with someone cheaper.

A friend has recently completed an RYA Advanced Race Officer course. The chatter there was an about a weather app called “Predict Wind”. Have you seen it? I’m using the free version, but the key thing is that you get to see all the wholesale layer of information on one screen – and you can make up your own mind what the breeze will be.

(this morning’s data above…)

I like to view average speed, direction and the expected gust speed. The photo above shows you the screen I use for this. Average speed at the top, then direction and gust predictions below that. You can just see the top three rows of the gust forecast and have to scroll down to see the rest.

Each row you can see is labelled P, G, U, A, S etc. I think this indicates the wholesale source of the wind data. Someone like the BBC or Apple will use just one of those rows that you can see. In fact if you look at the BBC app and Predict Wind simultaneously, you can work out which one it is.

Even on the morning of the forecast (the screenshot above is for this morning…), you can see how much forecaster opinion varies, but at least when you see them all together you can make a few decisions of your own. Some days, they all agree, then you really know what’s coming !!

Give it a try and let us know what you think!