Alps

Any journey from the Czech Republic to the south of Europe leads over the Alps. Weather permitting I usually fly directly to Linz, Trieste and from there then either to the south-east to Croatia, Albania, Greece etc. or to the south-west to northern Italy, southern France a possibly further to Spain.

If the cloud base is low, it is not possible to get through and above the clouds under the visual flight rules (VFR). Then the route to take is to slip around Vienna towards the Balaton lake in Hungary and there from continue to Croatia or northern Italy. The mountains on this route are much lower.  Just the journey takes about an hour longer.