@Hecky 100m layer is also above ground level (above model terrain), it is the same case like 10m level.
Upper layers display values for isobaric surfaces, e.g. 850hPa, not for exact altitude. AMSL value in the tooltip is only approximation.
For consideration: Integration of user-defined plume models. Or, Windytv built-in plume models. For example, I wonder how the UI at http://weather.hawaii.edu/vmap/hysplit/, modeling Hawaii volcano smog, might be presented on top of Windytv, using Windytv wind data. Then, it occurred to me this might be a nice source of income for Windytv, fee-paid for "business" use of an API. There are probably 10's or 100's of thousands of national, state, and local hazmat and disaster-planning departments around the world who have prepared (or want to prepare) plume-model applications, to track release of airborne toxins. No doubt they would be pleased to move their models to Windytv, and willing to pay for it.