PREVAILING WESTERLIES are winds that go against the trade winds. They originate from high pressure areas and go from the west to the east between the latitudes of 30-60 degrees. They go towards the poles and steer extratropical cyclones.
POLAR EASTERLIES are cold, dry prevailing winds. They blow from the high pressure areas of the polar highs at the poles ad go to the low pressure areas within the Westerlies at high altitudes.