[surreal1221]

A lesson in prevailing and sector visbility may be in hand.

Yes, most tower FPC's are certified weather observers, but the odds of them actually doing any type of observing are pretty slim these days. Plus, the vantage point for a controller is much different than a surface based observer / automated sensor.

Also, what airport is this? The observation may be automated, and all towers do have the ability to augment / amend the observation before it is sent out. . .BUT. . .if there was a SFC based human observer monitoring the system he/she is the one who would augment / amend the observation.