Wind direction in Low Pressure areas should say something about the temperature - the air drawn southward from Canada into the US should be cool. Air being drawn Northward into the Mississippi River Valley from the Gulf of Mexico should be much warmer. The air coming in from Canada has a very low dewpoint temperature, whereas the air coming in form the Gulf of Mexico has a much higher dewpoint temperature. This creates a Front. This particular front is called a Cold Front - cold air hitting the warm air from the side.
Warm air is lighter and less dense.
When cold air thrusts underneath it the hot air rises. We can see this happening in the use of a hot air balloon. The cold front in this area results in much precipitation around Kansas. Air can also be traced back to the Atlantic in between other areas of temperature on the map. More about fronts will be discussed later on in class.