Station model

How to read it

NOAA’s Weather Prediction Center says the arrangement of data around the station location is the station model, standardized by international agreement. In NOAA’s JetStream layout the temperature is at the upper left, in Fahrenheit in the US; the visibility in miles and the present weather symbol are on the second row at the left; the dew point is at the lower left; and the sea-level pressure is at the upper right. The middle right has the pressure change over the last three hours and a symbol for its trend, the lower right the past weather, and a Wind barb runs from the circle. The filling of the circle is the Sky cover circles.

The pressure is in tenths of a millibar with the leading 9 or 10 left off, WPC explains: 410 means 1041.0 mb and 987 means 998.7 mb. JetStream says to add whichever of 9 or 10 gives a value closer to 1000 mb. WPC plots a present weather symbol only when precipitation is falling or something is reducing visibility, such as Rain symbol or Fog symbol.

Also searched as: circle with numbers on a weather map, station circle, station plot, surface station plot, weather station model.

Simplified plots

Few charts show the full plot. JetStream notes that most computer-drawn maps leave out the cloud types, cloud heights and past weather. A Met Office teaching pack says the Met Office uses a much more complex station circle than its simplified version, with temperature top left and pressure top right.

Differences by country

Temperature and dew point are in degrees Fahrenheit in the United States and in degrees Celsius in most other countries, according to the University of Wisconsin–Madison’s course notes. The same notes describe the layout as a clock: temperature at 10 o’clock, pressure at 2 o’clock and dew point at 8 o’clock. The WMO’s manual adds that an automatic station is shown with a triangle drawn round the station circle.