Paris Alston: This is GBH’s Morning Edition. When trying to make sense of the weather and meteorological patterns, there are a lot of helpful tools out there. One of them is isobars, the curved lines ...

A bar is a metric unit of pressure and isobars are lines on a weather map that connect points of equal pressure. Since variations in air pressure drive the atmosphere’s winds, isobars also give ...

Isobar: On a weather map, a line drawn through all points of equal air pressure. Isobars form closed loops, and cannot branch or end. Isobaric patterns identify areas of relative high and low air ...

MIKE MOSS SAYS: Randy, There isn't a single, enformced standard for what we would call the "contour interval" for pressure analyses. However, there are three such spacings that are by far the most ...

MIKE MOSS SAYS: Phil, Winds would be perpendicular to the isobars is not for the rotation of the earth, which imposes a virtual force called the Coriolis effect. Over a significant time and distance ...

CONFUSED by a trough? Don’t know the difference between a low and high? Here’s how to make sense of the weather. And while the weather presenter pointing at all the bright lines and markers on the ...