https://en.wikipedia.org/wiki/Weather_forecasting
"Day5pressureforecast" by Hydrometeorological Prediction Center - http://www.wpc.ncep.noaa.gov/medr/day5nav.html. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Day5pressureforecast.png#/media/File:Day5pressureforecast.png