If the forecast holds, and it is 13mph (5.8m/s or 11 knots), you can NOT ride on that boardsize with your weight and a 15m2 Cult.
I assume it is summerconditions ?
If the wind is just a bit higher than 13mph, you might be able to ride, but most likely not hold ground.
I think you need around 15mph, before you can go on such a board, and a bit more in order to go upwind
But forecasts are only forecasts - maybe there will be more wind