20% Chance of rain - how people interpret probability

[unome]

from the NPR series; All Things Considered - Risk & Reason http://www.npr.org/series/333708682/risk-and-reason

http://www.npr.org/2014/07/22/332650051 ... t=20140722

[jasons2k]

At one time, the NWS definition meant "There is x% of a chance of measurable precipitation falling at any given point within the forecast grid" but I guess that's just too complicated for people to understand.

Now there are on-camera mets saying "20% chance of rain means that approximately 20% of you will see some rain".

I grew-up being told by the NWS and in my first meteorology class that is NOT the definition, but rather a very common misconception. It seems these days the 'misconception' has become the accepted norm.

I dunno, maybe I am getting older, and thereby old-fashioned, as I think this is just another dumbing-down of people.