Login/Register Subscription Info
To share images easily, download the free Imgur Community Extension for Chrome.
About This Map
Geopotential height is the altitude at which the air is at a given pressure at a given moment. When meteorologists mention "upper-level low pressure systems", they are referring to low geopotential heights, usually at the 500mb level. Low geopotential heights are often associated with storm systems and cold air. Geopotential height anomaly is the departure of the geopotential height from average at a given level. On our weather maps, geopotential height and geopotential height anomaly are given in decameters. Wind is the sustained wind speed and direction at a given level of the atmosphere at a given moment. Wind gust is the speed of wind gusts at a given moment. On our weather maps, wind speed and wind gust are given in knots or miles per hour. Absolute vorticity is the strength of rotation present at a given moment. Positive values represent counterclockwise rotation, and negative values represent clockwise rotation. Highly positive values often represent storm systems. On our weather maps, absolute vorticity is given in units of .00001 hertz.