METAR Overlay – how to turn them on and what do they mean?
METARs are those coloured little circles on the map you may have seen when you first started AvPlan EFB. They are a great way of getting weather information at a glance, and consist of three parts:
- The circle (location)
- The wind vector (tail)
- The wind strength (feathers)
You can turn them on or off by selecting METARs in the Weather Overlay menu. This is the RADAR icon, in the top right of the En Route pane.
First, lets talk about the circle. These display in five different colours, depending on the conditions:
- Green: VFR
- Blue: Marginal VFR (eg. < 2500′ AGL cloud base)
- Yellow: IFR (eg. < 1000′ AGL cloud base)
- Red: Low IFR (eg. < 600′ AGL cloud base)
You also may have noticed the grey METARs as well? They are weather stations that don’t have visual/cloud sensing capabilities. These may only report wind and QNH.
Next, the wind direction. Each METAR points into wind (or, to put it another way – the wind tail is on the upwind side of the station). Usually, these are black in colour – however, if the wind tail turns red, it denotes that a SPECI report is current for that station, not just a regularly scheduled report.
Finally, the wind speed bars (or the ‘feathers’). Each full bar denotes ten knots of peak wind speed. Partial bars can also be present, combining with the full bars (up to four full bars and one partial) to display the wind speed at a glance. For example, one-and-a-half bars would mean ~15 knots. Three-and-a-half bars would mean ~35 knots. The partial bars can also be a little smaller depending on the last digit in the wind speed.
But what happens if it’s above 50 knots, I hear you ask? Well, the four bars become a black triangle. That’s when it’s really windy!
If you wish to read the full METAR text for any station, simply tap the circle and the METAR will appear as the first listing within the ‘Nearest Items’ list.
METAR dots are also visible in the flight log, even if you don’t happen to have the METAR overlay turned on:
You can read more about the at-a-glance METARs here.