The synoptic, or medium, scale of meteorology studies and analyzes large-scale weather systems, particularly high- and low-pressure systems and hurricanes.
"Synoptic" comes from the Greek meaning "at the same time". It's used to refer to this scale of meteorology because the observations for mapping these weather systems are taken at the same time throughout the world on three-hour or six-hour intervals as specified by The World Meteorology Organization.
The observations taken include sky cover, the state of the sky, atmospheric pressure reduced to sea level, cloud height, temperature, wind speed and direction, dew point, amount of precipitation, hydrometeors and lithometeors and special phenomena.
To defeat the confusion caused by the multitude of time zones, meteorologists create a common point in time by using Universal Time Coordinate (UTC) or Zulu time (Z). Weather products such as maps, radar images, and satellite images use Zulu time.
If you've ever watched the weather report on the television news, you've seen a synoptic map. It's the large, colorful map of the country showing which regions have low or high pressure systems and where it's raining or snowing.
