Difference Between Onshore And Offshore Flow

Onshore flow describes the movement of any weather feature moving towards the shore. The most common weather features that are affiliated with onshore flow are Hurricanes and the daily sea breeze. What happens with a hurricane is the Northeast side of the storm will produce winds out of the Southeast to South which will force the ocean water (Storm Surge) towards the coast along with all the extensive precipitation shields. Another feature is known as the Sea breeze. The sea breeze happens during the afternoon when the ocean waters and the land are at different temps. The air over the land is warmer than the water causing the air to rise vertically over the land and the air from the ocean moves in to shore and fills in the empty space along the coast, this creates afternoon t-storms just about 5-10miles on shore near the coast.

Offshore flow describes the movement of any weather feature moving away from land and to the sea. The most common weather features are again with a hurricane. If you recall during Hurricane Katrina, remember that places in Louisiana were dealing with the winds and water of the lakes. The reason for this is that the winds were blowing from the North-Northeast forcing all the air and water away from the shore. Another feature is the land breeze which occurs during the evening hours. This is when the land gets cooler than the water creating the air over the water to go upwards and then the cooler air over the land moves out over the water to fill in the space.