How to read weather maps: Winds around High and Low pressure systems

The winds around High and Low pressure systems are what transport air masses northward and southward. These systems generally move from west to east across the continent. Compare this image to that of the air masses below.

• Winds around lows blow counter-clockwise and slightly inward towards the low pressure center
• Winds around highs blow clockwise and slightly outward from the high pressure center
• Winds ahead (east) of low pressure systems and behind (west) of high pressure systems tend to be southerly and bring in cT or mT air masses
  
• Winds behind (west of) lows and ahead (east) of highs tend to be northwesterly and bring in cP air masses.