On an upper-level chart the wind tends to blow
A) at right angles to the isobars or contour lines.
B) parallel to the isobars or contours.
C) at an angle between 10 and 30 to the contours and towards lower pressure.
D) at constant speed.

Question

Quizplus · Accepted Answer

On an upper-level chart, the wind tends to blow parallel to the isobars or contours. This is known as geostrophic flow, which is a balance between the pressure gradient force and the Coriolis force. The wind blows from higher pressure to lower pressure, but the Coriolis force deflects it to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, resulting in the parallel flow along the isobars or contours.

On an Upper-Level Chart the Wind Tends to Blow