Is the weather *globally* dynamic?

.... or is just *locally* dynamic.Now I've done one or two experiments just around local zones where thin overcast stratus layers will break up at dusk (absolutely fantastic). But has anyone downloaded a static real weather snapshot, flew half way round a continent, returned to the same place and found the weather significantly different? I haven't done it myself as I haven't had too much time to do it!I'm just thinking that the weather engine would have to do some serious number crunching to calculate changes for every reporting station, and that would just simply drain CPU resources - for background work that you may never benefit from. Or does the weather engine divide the weather world into *zones* in which only one zone at a time changes dynamically?