Fame
It was James Dalton who put weather forecasting on the map. Born in 1766, Dalton invented instruments that were used to record the weather. Despite the crude nature of his instruments (crude in that they were roughly fashioned, not because they had raunchy images on them or anything), Dalton compiled a massive amount of data for the U.K. He was able to turn crazy weather predicting practices into an actual science. Sorry, Merlin—you're out of a job.
In addition, Dalton's atomic theory established him as one of the most influential scientists of all time. You may not get that lucky. Most of the fame that you are likely to receive will be from recording data correctly and predicting weather changes. Hardly rock star material.
Some weathercasters, however, have managed to carve out a place for themselves in popular culture. Al Roker, John Coleman, and Dr. Steve Lyons have become household names. However, Dr. Steve Lyons is the only one out of the three that has a PhD. in meteorology. Thank goodness, because "Dr. Al Roker" just doesn't look right.