Question

where would i draw the isobars at 4mb intervals ??

Answer 1

I'm a meteorologist and I do lot of surface analysis. They key is not where to put 4 mb intervals its the labeling of your isobars need to be 4 mb. What I do when drawing isobars is find the region where the max and min pressure are observed. You can start from either one from a high pressure or low pressure. When you draw the isobars you want to make sure they are 4mb difference between each isobar.