| Secret Meteorological Office charts show the alarming swirl of isobars converging in black lines over the Channel. |
| Near the ground the winds are deflected across the contours, or isobars, towards the low pressure, due to friction. |
| The lines on a weather chart are known as isobars and represent areas of equal pressure. |
| When positioning isobars, assume a steady pressure change with distance between neighbouring stations. |
| When isobars on a weather chart are close together, it will be a blustery day. |
| The balance of forces is lost and the flow crosses the isobars towards the low pressure. |
