I spent time with the family in California, wiping out any chance of a white Christmas, although I hear that the probability would have been miniscule even had I stayed.
I did come across a graphic that tried to drive the point home, via NOAA.
Unfortunately, this reminded me a little of the controversial Florida gun-deaths chart (see here):
In this graphic, the designer played with the up-is-bigger convention, drawing some loud dissent.
Begin with the question addressed by the NOAA graphic: which parts of the country has the highest likelihood of having a white Christmas? My first instinct is to look at the darkest regions, which ironically match the places with the smallest chance of snow.
Surely, the designer's idea is to play with white Christmas. But I am not liking the result.
Then, I happen upon an older version (2012) of this map, also done by NOAA. (See this Washington Post blog for example.)
There are a number of design choices that make this version more effective.
The use of an unrelated brown color to cordon off the bottom category (0-10%) is a great idea.
Similarly, the play of hue and shade allows readers to see the data at multiple levels, first at the top level of more likely, less likely, and not likely, and then at the more detailed level of 10 categories.
Finally, there is no whiteness inside the US boundary. The top category is the lightest shade of purple, not exactly white. In the 2015 version above, the white of the snowy regions is not differentiated from the white of the Great Lakes.
I am still not convinced about the inversion of the darker-is-larger convention though. How about you?