Symbolic Station Model

Element Explanation

N Total amount of cloud cover dd True direction from which the wind is blowing ff Wind speed in knots VV Visibility in miles and fractions ww Present weather W Past weather Barometric Pressure in millibars reduced to sea ppp level The Symbolic Station Model shows how ob- TT Current air temperature served weather elements are arranged on a standard station model plot. The plot above uses symbolic Nh Fraction of sky covered by low clouds codes to identify each weather element. Some of the Symbol of predominating low clouds elements, such as temperature, dew point, pressure, CL and precipitation totals are measured and therefore Height of base of cloud—uses a code not actual are plotted as numbers. Other elements are repre- h cloud height sented by symbols. Weather Briefing, L.C. uses the Cm Symbol of predominating middle clouds symbols adopted by the U.S. Weather Bureau in 1944 and now by the U.S. National Weather Service and Ch Symbol of predominating high clouds the World Meteorological Organization. These stand- d d Temperature of dew point ardized plots make it easy to interpret weather obser- T T vations made anywhere in the world. a Characteristic of barometric trace Today station model plots seldom display all pp Pressure change in previous 3 hours of the weather elements. In many cases this is for the sake of simplicity but another reason is that automat- RR Amount of precipitation in inches to the nearest ed weather stations do not observe all possible ele- hundredth of an inch ments. For example, automated stations do not ob- Time precipitation began or ended—used a Rt serve cloud types. More information about station code not the actual time model plots is found at www.weatherbriefing.com.