The Ambarometer is an ambient display of the local weather trend. It displays the atmospheric barometric pressure mapped to a color scale where red is low pressure typical of storm systems, and blue is high pressure characteristic of fair weather.
The Ambarometer also displays the pressure trend over the past 21 hours on its seven levels. The top level is the current pressure and older values are displayed moving downwards in 3 hour intervals, like a strip chart. Thus falling pressure forecasts a coming storm in the top left image; while the right shows a return to high pressure and fair weather.
Classic aneroid barometers have a wonderful affordance: tapping the instrument causes the needle to move slightly. Thus you could tell the trend -- rising or falling -- which can be more useful than the current value, as falling pressure indicates an approaching storm. The Ambarometer reproduces this functionality: tapping the top of the instrument causes a scrolling barograph display of the pressure trends of the past 24 hours.