QA issues to address

[limnoliver]

• - Daily means from sub-daily observations. We should flag sub-daily data that deviates too far from other observations during that day. That is, if there were 5 observations with a mistaken entry (2.3, 2.3, 2.3, 2.3, 23), our calculated mean would be wrong. We should either flag the mean or drop that errant observation before taking the mean.
• - Create flag for when the min/max are likely not true min/max. This could be as simple as flagging those observations where the min, max, and mean values are all the same, or when min/max are the same.
• - Add checks to ensure min < mean < max
• - See John's spot-check of PA and the algorithm flagging potentially "good" data as suspect.
• - add flag similar to what NorWEST does, which is to flag any day with >3 degree mean temperature difference