Presentation at the NEWA Final Workshop in Bilbao. The Ryningsnän experiment in forested terrain is used to define a case study for testing atmospheric boundary layer models in forest canopies during diurnal cycles. A technique is presented based on prescribing net radiative heat flux balance at the top of the canopy, instead of surface temperature, and use geostrophic pressure gradient to drive the simulation. The results are reasonably good showing promise for further implementation in complex terrain sites.