dynamic Weather is the actual weather that is at a specific latitude & longitude
FSX had real world weather but I would not call it dynamic as it did not update that often
I use Active Sky 2016 and Active Sky cloud art and it will give you the exact weather at all of your way points in a flight plan and is very realistic. you actually fly in the weather that is at that location and the change is very realistic as it changes from a thunderstorm to clear skies. Clouds just do not pop up out of nowhere and all of a sudden.