The modern numerical weather prediction and regional climate simulation modelsfrequently use hydrostatic approximation in the basic primitive equations. Howeveron increasing horizontal and vertical resolution of the simulations, the validityof this approximation is questionable. In these numerical investigations, the impactof hydrostatic approximation in the mesoscale regime in a domain over Greenlandfocusing on the interaction with orographic forcing is investigated. The resultantchanges in precipitation pattern over Greenland are assessed in a case study inresponse to increasing resolution. The impact of the choice of vertical coordinateis also discussed.