Upper-level wind blows parallel to isobars, speed indicated by spacing of the isobars. Winds blow out of subtropical highs, deflected to the west, converge on ITCZ . Surface westerlies a. Between 30-60 lat., the prevailing wind direction is from the west. Flow out of subtropical highs into midlatitudes, deflected towards the east.
Gyres cause cold currents off west coasts, warm currents off east coasts.