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)

Is there an operational reason why it would be more relevant for the pilot to have the wind speed rounded down to the next lowest multiple of 5 instead of rounded to the closest multiple of 5?

Usually, you would prefer the "nearest" rounding as it would minimise roundoff errors in calculations. The only real exception is when it is important to always round in a "safe" direction, e.g. when checking operating minima.