What are the worst and most common mistakes made by rookie forecasters?

[stefan]

I have an example myself today when I was forecasting the wind. I forecasted under the MOS guidance for the GFS and the NAM. My professor then told me quite bluntly that it is never a good idea to forecast under the MOS guidance for wind because they are almost always too low. Any one here have any good stories about mistakes you made when you were green?

 

[KyleB]

Commonly i made two mistakes, wind direction i usually got it wrong and i almost predicted a higher temperature than actually occurred...

 

[Incipient_planck]

Being too dependent on persistence. Forecasting a record, although you are instructed not to or letting politics interfere with good meteorological reasoning.