Winds aloft just puts in the wind conditions at all altitudes according to real world observations.  All wind will put you off course unless it is a perfect head or tail wind but you can correct for the wind by turning your plane into the wind by half the wind commponent.

For example:  in you are flying on heading 90 and to have a 20 knot wind from the right.  Then you would turn the plane to the right, 10 degrees (half the wind component) so you are flying on heading 100.

It doesn't always work because of gusts and other things, but once you gain experience, winds aloft are really cool.

Chris