Understanding Isobars Julie Ann Hugick Eastchester M.S. This slide show helps you learn how to draw the isobars (lines of equal pressure) around high and low centers. It also shows the ways in which winds blow.

ISOLINE ACTIVITY: In PEN, uncode each pressure: 103= 1010.3 In PENCIL, label the highest pressure H and the lowest pressure L. 3. For the H draw the following isobars: 1016, 1012, 1008 mb 4. For the L draw the following isobars: 996, 1000, 1004 mb 5. For each wind indicator- show wind movement.

1016 mb H L

1016 mb H L 1012 mb

1016 mb H L 1012 mb 1008 mb

1016 mb H L 996 mb 1012 mb 1008 mb

1016 mb H L 996 mb 1012 mb 1000 mb 1008 mb

1016 mb H L 996 mb 1012 mb 1000 mb 1008 mb 1004 mb

1016 mb H L 996 mb 1012 mb 1000 mb 1008 mb 1004 mb

In what area is the wind speeds the greatest? Follow up questions: Describe the wind motion in the H. Describe the wind motion in the L. In what area is the wind speeds the greatest? Winds go from ___ to ____ for pressure.

Summary Winds around a High blow in a clockwise direction away from the center. (“The clock is high.”) Highs usually have fair weather. Winds around a Low blow in a counter-clockwise and inward. (“The counter is low.”) Low pressure systems often have stormy or unsettled weather.