Where are you located? This could be because of the jet stream, storm patterns, terrain, pretty much anything. More info will help us decipher what's
going on.
The rising air accumulates aloft forming an area of higher pressure. Relative to the land at the same elevation, air flows back toward land from high pressure to low pressure . Once back over land, the air cools, increases in density and then sinks causing an increase in density and high pressure . Gravity pulls the dense air offshore again completing the circulation.