A Variably, Fifty Percent Chance...
The... err... "scientific" art of taking a wild guess about the weather.
On the surface meteorology involves a large body of meteorologists who are trained at fine academic institutions. They have serious discussions about thousands of little bits of data (which are given impressive names like pressure, dew point, specific humidity, vertical velocity, vorticity, etc...) collected by both human observers and intelligent robotic devices (called ASOS) from points all over the world. Usually added to these talks are a bit using different kinds of pictures taken from high up in space (also given impressive names like infrared and water vapor). Then the "scientists" draw lines and symbols on many, various maps and put together a forecast, which supposedly tells the weather for the next several days. This forecast is then distributed to the general public through the media
The unseen truth is that after all the serious talks have taken place the group ends up taking a semi-informative (or completely wild) guess and continues by coming up with some sort of excuse if the guess turns out to be the wrong one. The wonderful thing about the weather, is that a meteorologist can be vague enough to the point where he or she cannot possibly be wrong. In that event, an excuse is only a fail safe.
Disclaimer: This article is not meant to be offensive to anyone involved in the Meteorological profession. It is only a semi-exagerated version of the truth.