Low-pressure Systems

Weather maps show us areas of swirling air by indicating areas of high barometric pressure (H) and low barometric pressure (L). The air circulates clockwise around a high pressure center and circulates counter-clockwise around a low (L). Birds want to fly with a tailwind, which means with winds blowing in the same direction they are flying. Lows begin with south winds, but they also often bring bad weather, such as storms or heavy rain. So, even though the winds may be blowing in the right direction, flying conditions may not be good.

Direction of Circulation around high/low pressure
NOAA