Meso Scale Lies Outside GWC

Status: Closed - part of windPRO 3.0 Service Pack 3

Fixed in build: 630

In WAsP 11.02.0062 there are some new constraints on how WAsP interpolates/extrapolates in the default calculation heights and roughness lengths (both defined in the WAsP parameters). The consequence is that WAsP can no longer calculate outside the limits of the 5 default heights and roughness lengths. This is especially a problem for roughness length where the default maximum is 1.5 and in windPRO we use 1.6 for roughness class 4. This basically means if you have a project with roughness class 4 you will get the following error: “Error: -1, climate calculation: meso-scale roughness lies outside gwc roughness classes” if you use the default WAsP parameters.

To fix the problem you can change the maximum roughness length in the WAsP parameters to 1.6. This fix is only possible if the wind statistics is generated in windPRO either via STATGEN or MCP. If you are using old wind statistics where that you can't recalculate with other WAsP parameters there is a new tool in windPRO 3 build 630 that allows you to do extrapolation in existing wws files. You will find the tool in the Tools menu as Wind statistic roughness extrapolator.