Often with thunderstorm warnings we come ashore and the thunderstorm passes us by miles and we wonder why we did that.
There are a couple of issues with thunderstorms that make them a difficult risk to manage safely.
We traditionally think of weather risks moving in the same direction as the wind, but from the pictures below, you can see:
+ These thunderstorms are moving up wind!
+ They fluctuate in intensity – and risk.
+ Two separate clusters can combine and form a new concentrated cluster.
+ Thunderstorm clusters can also spread outwards.
+ Thunderstorms can re-appear where they have already passed!
So there are a lot of variables with thunderstorms and how they will impact safety.
At school sports fields, if a thunderstorm is within 10km they immediately bring all the players indoors. 10 minutes is 30 seconds between the lightning and the thunder.
We follow the same policy and it can take 20-30 minutes to get everyone ashore: so we do need to act promptly when we get a thunderstorm warning.
The consolation is that they are usually associated with conditions that are unsuitable for racing.