As a pilot, it’s essential to think in 3D. A ground-based forecast of the sort transmitted after the news isn’t sufficient preparation for a flight, as wind speed and direction vary with altitude. This means that to plan a flight accurately, you need to be aware of wind speed and direction at your planned altitude. The forecast you need in order to do this is the Met Office 214 – the UK Spot Winds.
Start by logging into the Met Office aviation section – click ‘Launch’ once you’ve registered your details.
It’s vital to select the forecast that’s valid for the time window in which you’re going to fly – there will be several listed, including some for time periods that have already been and gone. You can double check the validity period at the top of the chart, where it tells you the times and dates. This one is valid between 9am and 3pm UTC. However, though the validity window says 09 – 15 UTC, you’ll notice above this that it says ‘Forecast for 12 UTC’ – this means that it is actually a snapshot of the forecast winds at 12:00 UTC; the winds before and after this time will probably be slightly different. (It’s also worth remembering that UTC is the same as GMT; therefore it is currently an hour behind UK local time, as we’re on BST.)
Choose the box that covers the region you’re flying in. Each box is labelled with Lat/Long coordinates, which are those of the point at which the forecast applies. At MotorGlide, we’re looking at the one four rows down and three across, over the Midlands.
The columns in each box are as follows:
Column 1 – altitude.
Column 2 – wind direction
Column 3 – wind speed
Column 4 – air temperature (Celsius)
For example, for our Midlands box, the wind is 210 degrees at 5kts, with an air temperature of +7 degrees.
A couple of interesting points to remark on this particular forecast: firstly the unusual occurrence of “CALM” at 5,000ft, meaning no significant wind. Secondly, “VRB” at 2,000ft, which indicates that the wind direction is variable. At 5kts a variable wind direction isn’t too much to worry about – it’s when it’s gusting in different directions that life gets difficult. It just means that it’s going to be harder to calculate accurate flight times between destinations.
So what if you’re between boxes?
If you’re slap bang in the middle of two boxes, simply take the difference between the two. For instance, if you were between our Midlands box and the one to the right of it, and you want to know wind speed and direction at 1,000ft, you have:
5kts – 10kts – so about 7kts
210 – 150 degrees – so about 180 degrees (210 – 150 = 60, half 60 = 30, 150 + 30 = 180)
All make sense?
If you’re preparing for your meteorology exam, why not come to MotorGlide for your ground school and exam? We’ll take you through everything you need to know for the exam and then you take the exam with us at our Long Marston base. What’s more, we won’t charge you until you pass.