Step 1:          Locate the Low-pressure system by finding the lowest pressure values and by the fact that winds around a low circulate in a counterclockwise direction.

Step 2:          Find & draw the COLD FRONT, which generally extends southward or southwestward from the center of the low-pressure system.  Winds in advance of the cold front generally come from a south or southwesterly direction while behind the cold front the winds are generally from the west or northwest.  Temperatures are generally warm in advance of the cold front while behind the cold front temperatures are cold.

Step 3:          Find and draw the WARM FRONT, which usually extends eastward, northeastward or southeastward from the center of the low-pressure system.  WINDS to the north of the warm front are usually blowing from the east or southeast while winds to the south of the warm front winds are generally from the south.  TEMPERATURES to the north of the warm front are generally cold while temperatures to the south of the warm front are generally warm.  PRECIPITATION is most often found north of the warm front and very rarely south of the front. (Except near the oncoming cold front).

Step 4:          Draw isobars so that the pressure interval is 4 millibars (every 40 units).  Example: 000,040,080,012 etc.  Isobars are nearly straight lines in the warm sector of the low pressure system and also that the isobars “bend” as they cross the warm and cold fronts, always bending away from low pressure.

Step 5:          Label all isobars.  (Hint: leave a small section of the isobar located in the warm sector blank.  In that small section, label the isobar.

Step 6:          If there is precipitation on the weather map, outline the entire precipitation area and then shade the precipitation area lightly in green. If it is during the cold season, put stars (*) over the snow areas and (..) Dots over the rain areas and then separate the two areas with a dividing line. Thunderstorms should be indicated in red.

Try your hand at analyzing the following maps!

Map2     Map2-A
Map3     Map3-A
Map4     Map4-A