FORCE EQUIVALENT SPEED   DESCRIPTION      SPECIFICATIONS FOR USE ON LAND

     10 m above ground

     Miles/hour knots

0       0-1      0-1      Calm             Calm; smoke rises vertical.

1       1-3      1-3      Light air        Direction of wind shown by

                                           smoke drift, but not by wind

                                           vanes.

2       4-7      4-6      Light Breeze     Wind felt on face; leaves

                                           rustle; ordinary vanes moved

                                           by wind.

3       8-12     7-10     Gentle Breeze    Leaves and small twigs in

                                           constant motion; wind extends

                                           light flag.

4      13-18    11-16     Moderate Breeze  Raises dust and loose paper;

                                           small branches are moved.

5      19-24    17-21     Fresh Breeze     Small trees in leaf begin to

                                           sway; crested wavelets form on

                                           inland waters.

6      25-31    22-27     Strong Breeze    Large branches in motion;

                                           whistling heard in telegraph

                                           wires; umbrellas used with

                                           difficulty.

7      32-38    28-33     Near Gale        Whole trees in motion;

                                           Inconvenience felt when walking

                                           against the wind.

8      39-46    34-40     Gale             Breaks twigs off trees;

                                           Generally impedes progress.

9      47-54    41-47     Severe Gale      Slight structural damage occurs

                                           (chimney-pots and slates removed).

10     55-63    48-55     Storm            Seldom experienced inland; trees

                                           uprooted; considerable structural

                                           damage occurs.

11    64-72     56-63     Violent Storm    Very rarely experienced;

                                           accompanied by wide-spread damage.

12    73-83     64-71     Hurricane                        --