User manual

XCSoar User Manual
The forecast cloud base is determined by the altitude at which
the dew point intersects the maximum forecast temperature on the
ground, cooled adiabatically as it rises according to the dry adia-
batic lapse rate. If no clouds are forecast, the cloud base is reported
as zero.
6.9 Analysis dialog
The analysis dialog is used to see several aspects of the atmo-
sphere. This is accessed via the menu under:
INFO . Analysis
Several pages of interest:
Wind at altitude : This shows a graph of the wind speed versus height, and
shows the wind vector at several heights.
The ‘Set wind’ button opens the wind settings dialog (e.g. to
manually set the wind).
Temperature trace : This page is only available if a supported instrument is con-
nected to XCSoar that produces outside air temperature and
humidity. The chart shows the variation of dry air tempera-
ture, dew point temperature and outside air temperature with
height. The convection forecast is summarised as the esti-
mated thermal convection height and estimated cloud base.
93