Converse of object

• tighten: The low had moved NE to be in the Bay of Biscay tightening isobars across the S UK.

• pack: Too many low pressure systems with closely packed isobars are stubbornly sitting in our path.

• show: Second is the pressure chart showing the isobars in the South Atlantic.

Adjective modifier

• slack: At 0900 GMT pressure here was 1018 mb and with slack isobars there was little or no wind, what there was was S'ly.

Modifies a noun

• chart: In contrast, a front is actually a squiggly line on the isobar chart.