Predicting the weather.
Ability Score(s): Common Sense
Usage: Predicting the weather for the near future; this is often used by woodsmen or nature. In order to predict the weather you must have a view of the outdoors or the sky. Determining the weather is based on how far out you're trying to predict; same day predictions start at DC 20 whereas for each day you attempt to predict out to you increase the DC by 5.
Predicting natural disasters increases the DC by 10 as well unless obvious signs exist.