At 0450Z the wind is from the SW, the station has low cloud and heavy rain; typical of an approaching warm front.  

By 0650Z the wind has veered, the rain has stopped, the temperature and dew point have both increased; all of these factors indicate that a warm front has passed through the station.  

As we go through the day the temperature builds to a maximum of 24ºC at 1450Z, the cloud dissipates and the visibility improves but the wind direction is fairly consistent.  

This indicates a normal diurnal variation in the same air mass; i.e. the passage of the warm sector.  

After 1450Z we see the thunderstorms and heavy rain associated with a cold front.  

By 1850Z the wind has veered and the temperature and dew point dropped indicating the completed passage of the cold front.