Name: _________________________________________ Date: _________________ Block: _____ WKST #
Drawing Isobars
Draw the 1008, 1012, 1016, 1020 and 1024 isobars on the map below. Hint: there will be two separate
pressure centers on the map. Be sure to go through each pressure number when drawing your isolines.
Isobar Interval = ___________ mb
1. Base your answer to the following question on the weather map provided below, which shows surface
air-pressure readings, in millibars, at various locations in the United States and Canada. The 1020millibar isobars have been drawn and labeled.
Draw the 1024- and 1028-millibar isobars on the weather map provided above. What type of pressure system
are both of these centers. Draw in the correct capital letter in the center of each.
2. Draw in the correct locations of the 996-mb, 1000-mb, and 1004-mb isobars on the map below.
3. Base your answer to the following question on the weather map below and on your knowledge of Earth
science. The weather map shows the center of a high-pressure system (H) and the center of a lowpressure system (L) affecting North America. Isobars are drawn for the eastern portion of the map, and
one isobar is drawn around the high-pressure center. Air pressures are shown at various points in the
western portion of the map. All air pressures were recorded in millibars (mb).
On the map above, draw the 1012 mb, 1016 mb, and 1020 mb isobars. Extend the isobars to the edges of the map if
they do not form closed curves.