Be aware that if a station reports hourly or less that the wunderground "magic" adds up the cumulative rainfall, so if the cumulative at 8am is 1mm and at 9am is still 1mm, it reports as 2mm
Could it be anthrogenic (sp?) snow, had some here in Norfolk earlier
Sadly, for those wishing for extreme cold and snow the charts are less likely to flip in this type of situation than when they were showing the easterly.