Why Does Weather Move East As Well As The Earth?

[ty_buchanan]

Why does the atmosphere with the weather move eastward at a faster rate than the earth?

[Old_Geezer]

Does it ? When I see the weather map more often than not stuff is coming in from the Atlantic in the west.

But if it does then I'd suspect drag might be a factor ? If the atmosphere moves at much the same rate as the planet beneath it then surely it has no compulsion to 'move' the opposite way to the planet's spin. The weather motion would be a variation of movement on top of that main movement.

[Old_Geezer]

To add, most movement is surely down to variable pressure over the surface. Hot air rises, cold falls, pressures varies and air in the high pressure area rushes to the low taking any cloud and rain with it.

[Mosaic]

The atmosphere is like the world's ocenas - which geologists increasingly see as one 'ocean' rather than disconnected units of seawater.
Both the ocean(s) and the layers of atmosphere 'churn' as they are influenced by heating, cooling, and the earth's rotation.
Some of the highest layers of atmosphere move very fast - the jet streams.
As fast currents move they pull in other air behind them. So weather systems migrate across areas of the globe, sometimes predictably and sometimes surprisingly. I'm amazed we can predict a week's weather when you look at the number of variable factors it requires to create a hurricane in Texas or a shower in Leeds.

[Old_Geezer]

First to say as I left the house I realised weather coming from the west is weather moving eastwards :-O So apologies for that bit ;-).

[heathfield]

If the Earth didn't rotate, warm air at the Equator would rise and move straight toward the poles. But consider the rotating Earth. The speed at which it's rotating toward the east is fastest on the Equator, and slowest at the poles. The rising air at the Equator moves north, (say), but it still keeps its eastward equatorial momentum, and so the further north it goes, the faster it moves to the east compared to the ground below.

[gen2]

What Heathfield has just described is called the Coriolis Effect.