Just R/C Helis

Beaufort Scale

Home Buyers Guide Links Gyro Contact

invert.jpg (5128 bytes)

Web Master



 

 

 

 

Get Adobe Reader

 

 

 

 

 

 

 

 

Beaufort Scale

The Beaufort Scale is regularly used in weather forecasts, something of interest to all outdoor modellers.

Here is the standard table describing the wind speed and effects of the various levels of the scale.

Force Description

Result

Wind speed

Km/h Knots
0 Calm Smoke rises vertically 0-1 <1
1 Light air Wind direction indicated by smoke but not wind vanes 1-5 1-3
2 Light breeze Wind noticeable, leaves move, wind vane moves. 6-11 4-6
3 Gentle breeze Leaves and small twigs in constant motion. 12-19 7-10
4 Moderate breeze Wind raises dust and loose paper. Small branches are moved. 20-29 11-16
5 Fresh breeze Small trees in leaf start to sway.Crested wavelets form on inland waters. 30-39 17-21
6 Strong breeze Large branches in motion, wind whistles. Umbrellas used with difficulty. 40-50 22-27
7 Near gale. Trees in motion, awkward to walk against wind. 51-61 28-33
8 Gale Twigs break, hard to walk. 62-74 34-40
9 Strong gale Some structural damage may occur, slates removed etc. 75-87 41-47
10 Storm Trees uprooted, considerable structural damage. 88-101 48-55
11 Violent storm Widespread damage. 102-117 56-63
12 Hurricane Widespread Structural damage. 118+ >63

Wind Chill Factor

Although the weather forecast give you a good idea of just how cold it's going to be on that slope, the actual air temperature is not the whole story: when you are outside; a flow of air will remove heat from you and the perceived temperature will be lower than the measured one.

The result is that you feel much colder when there is a wind, and this table will give you some idea just how much!

This drop in perceived temperature is known as the 'wind-chill factor', so for all you slope soarers, here's a little table that will tell you how cold it feels when the wind-chill factor is taken into account.

The left hand column is the actual air temperature, so find the correct one then follow the row across until you are under the wind speed. The temperature shown there is the perceived temperature caused by heat loss due to the wind.

Wind-chill Factor Table (in Fahrenheit)
AIR TEMP Wind speed in mph.
CALM 5 10 15 20 25 30 35 40
50 50 48 40 36 32 30 28 27 26
40 40 37 28 22 18 16 13 11 10
30 30 27 16 9 4 0 -2 -4 -6
20 20 16 4 -5 -10 -15 -18 -20 -21
10 10 6 -9 -18 -25 -29 -33 -35 -37
0 0 -5 -21 -36 -39 -44 -48 -49 -53
-10 -10 -15 -33 -45 -53 -59 -63 -67 -69
-20 -20 -26 -46 -58 -67 -74 -79 -82 -85
-30 -30 -36 -58 -72 -82 -87 -94 -98 -102

                                                      Home · Links ·Gyro · Buyers Guide  ·Beaufort Scale · Contact me