What is "focus point" in WRF-plots grid box? (python code)
A Skew-T/Log-p plot is a vertical profile from a point, and it appears in that code that the point you are plotting the skew-T for is 60.2 latitude, 11.08 longitude.  The snippet of code:

def getXY(lon,lat):
 x_nr = 0
 y_nr = 0
 while (lon[x_nr] &lt; lon_focuspoint):
  x_nr += 1
 while (lat[y_nr] &lt; lat_focuspoint):
  y_nr += 1


finds the closest grid point west and south of your focus point by setting the x and y gridpoints to 0 and incrementing the index as long as the latitude/longitude values at that grid point are less than the focus point.  This is what the focus point is for -- the lat/lon location you want the skew-t/log-p plot at.

The exception IndexError: index out of bounds. means that the above code tried to access a value lon[x_nr] or lat[y_nr] that was out of bounds.  This means that the latitude/longitude coordinate of your focus point is not within your domain.

To run the code successfully, edit the focus point to be a point within your model domain, specifically the value of latitude and longitude that you want the skew-t profile for.