I found discrepancies between wind numeric value and its representation


The wind vector shows 5 kt less than the numeric value when the speed is divisible by 5 kt.
If it is due to unit conversion and rounded value, e.g. 64 km/h = ~34.56 kt, rounded value = 35 kt, I suggest to round the vector to the closest value instead of rounding down, in the example vector of 35 kt instead of 30 kt.

Moreover, it is possible to show the wind vector for 5 kt with the short line at the second position like the third picture


source: https://upload.wikimedia.org/wikipedia/commons/c/c6/Wind_barbs.gif

Alexandre
Based at LSGL (Lausanne - La Blécherette, in Switzerland)

There isn't an "operational" reason, it's just my understanding of how wind barbs are used.

If we were to make a decision to round wind values to the nearest 5 knots and then draw the barbs, a wind value that's given in the What's Here menu as 33 knots would have a barb of 35 knots, which would be equally "inaccurate". I use quotes on that word because we are talking forecasts here, and these differences are both negligible in magnitude and relatively meaningless considering the forecast values are likely to differ in reality by more than the rounding under discussion.

You are right Tim. It's just that rounding down to the nearest 5 kts is arbitrary. You can make an argument for rounding to the nearest 5 kts. And you can find an argument for rounding upward to the nearest 5 kts. But rounding down to the nearest 5 kts is just arbitrary. Not that it would matter much. Simply hard to argue in favor of.

-- Chris.