PowerPoint Presentation
) FL180 (506.0 hPa) FL240 (392.7 hPa) FL300 (300.9 hPa) Each of these is calculated over a 100hPa deep layer centred on that flight level. For example this FL100 chart is calculated using data from 746.8hPa to 646.8 hPa. NIL TRACE LIGHT MOD SEV • Of course, a threshold could be applied to icing severity