Analyzing fronts requires looking at every meteorological variable.
Pressure: Pressure usually drops ahead of fronts and rises after the front passes. With a strong cold front, this can be dramatic. In some cases, the pressure will rise slowly ahead of a front, but more rapidly after the front passes. If the isobars are drawn on the map, the front will usually be found in a "trough" of lower pressure. It may be appropriate to show the isobar contour lines "kinked" at the front.
Temperature: Fronts usually seperate air masses of different temperature. Within an air mass, the isotherms will be widely spaced, indicating gradual changes in temperature over distance. Near a front, the isotherms will be closely spaced, indicating a rapid change in temperature. The front is usually located on the warm edge of the closely spaced (also referred to as packed) isotherms.
Moisture: Fronts usually seperate air masses having different amounts of moisture. When the moisture is the only significant change across a front, it is sometimes called a "dryline".
Winds: The winds typically shift speed and/or direction when a front passes. On the surface map, winds will usually be different in direction on one side of a front compared to the other.