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Land surface characteristics (soil moisture, leaf area index) have an impact upon temperature forecasts.    Significant differences in temperature can occur over a short distance where there is a sharp change of surface characteristics.   This can influence the location and development of subsequent convection.

Fig9.2.1.5: An example of incorrect assessment of heat and moisture fluxes (temperatures - diagram on left; dewpoints - diagram on right), at Cordoba 12 June 2017: HRES forecast temperatures and dewpoints (red) and observed temperatures and dewpoints (black).  HRES has under-estimated the maximum temperatures by some 3ºC.  

The left panel shows that during this very hot spell the maximum temperature, on 12th, was under-predicted by 3ºC. This may be due to unrepresented local factors, such as urbanisation, though on the other hand the signal is also typical of what we often see during extreme summer heatwaves.  This bias is a subject of current research; it may be symptomatic of an IFS inability to generate the superadiabatic near surface layers that one sometimes sees on radiosonde ascents.

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