Wind

Question 1

How should the wind direction be reported and rounded?

Answer 1

Wind direction is reported as the mean direction from which the wind is blowing during the preceding 10 minutes, in tens of degrees from True North, between 010 and 360. Values of 015, 265, etc are rounded down.

Question 2

Is a wind from the north reported as 000 or 360?

Answer 2

360

Question 3

When is a wind gust reported?

Answer 3

If it exceeds the mean speed by 10kts or more.

Question 4

How would you describe a wind discontinuity?

Answer 4

When during the 10 minute average period, there was a 30-degree change in mean direction or an increase/decrease in mean speed of 10kts or more, sustained for at least 2 minutes.

Question 5

When will a wind variation be reported?

Answer 5

When the mean wind speed is greater than 03 knots and the total variation in direction over the previous 10 minutes is 60 degrees or more but less than 180 degrees. Variations are reported in clockwise order (e.g 340V060).

Question 6

How is wind reported as Calm?

Answer 6

00000KT

Question 7

When is the wind direction coded as VRB?

Answer 7

• When the wind speed is 03 knots or less and when the variation in direction is more than 60 degrees but less than 180 degrees.
• When, at any wind speed, the variation in direction is greater than 180 degrees.

Question 8

Between what values is wind speed reported?

Answer 8

Between 01KT and 99KT

Question 9

How is a wind speed greater than 99 knots coded?

Answer 9

P99KT

Question 10

What equipment is used to measure wind data?

Answer 10

Anemometer.

Question 11

If the wind fails on SAMOS what must be coded into the Metterm to disable automatic wind acquisition?

Answer 11

Wind Off

Question 12

What contingencies are available at Gatwick to find wind data?

Answer 12

• Standalone surface wind equipment located in the pullout standby drawers
• Windsock
• Beaufort Scale