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• There is a dry bias during the dry season and first guess 2m temperatures can be too cold.  During the analysis process, soil moisture increments attempt to better represent 2m humidity.  These increments can be substantial.  However, this results in excessive soil moisture near the surface despite no precipitation.  This moisture in IFS can then incorrectly percolate to lower layers or even runoff on the surface.  In contrast, the increase in soil moisture from actual rainfall is normally realistic and much less.   Increments can override the impact of any noteworthy rainfall.
• Surface ground moisture limits the amount of diurnal surface warming and nighttime night time cooling leading to lower 2m temperature and higher 2m relative humidity being observed and forecast.
• Vegetation could be lush and green after previous wet period and/or evapotranspiration could be mis-represented.
• Errors in forecast advection of boundary layer air.  Diurnal influxes of moist sea air may replenish moisture and/or not be well forecast either in depth or penetration.
• Observation representativeness.  Insufficient information on atmospheric structure due to the lack of radiosonde. 

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