Hi, Morten My numbers for A and k are still off when compared to WAsP's. Can you please answer a couple more questions? At which point in the process of going from tab to lib does WAsP calculate the weibull parameters for the first time? From that point on, does it ever go back to probability distributions again, or are all calculations performed on A and k values? It seems that the first thing WAsP does is calculate the first and third moments per sector given the frequencies in the tab file. Then it redistributes those according to the veer angle going up to the geostrophic wind, and then again according to the backing angle coming down to the surface for a given roughness class (is this correct?). However, moments are statistical measures of the sector, while the veer angle is a function of G and u* and therefore also a function of u. There is no one veer angle value per sector. Does WAsP use an average veer angle or the veer angle for a specific speed to do this redistribution? Finally, when you say that the third moment and the probability of winds greater than the mean are conserved, are they conserved for a given roughness class no matter what height we are considering, or are they conserved for any roughness class and height? If the latter is the case, then the third moment calculated straight out of the tab file and redistributed across sectors according to the veer angle, will be the only third moment ever used in the entire calculation of the wind atlas? Thank you so much for helping me move along with my research! Paula