There is occasional confusion over sea level, raw, etc. and how to set it all properly. A lot of people probably don't check what's on WU (or weatherforyou.com or CWOP for that matter) as long as what's in front of them is right. In a recent survey we found people pay attention to the temperature, then wind, then humidity... barometric pressure was down the list a ways, after the short term forecast. Rain jumps in somewhere around wind and humidity if it's, well, raining.