Weather Maps

Weather maps are used traditionally used to show the national or local weather using graphics.  I will describe the different types of maps that you may come across so that you may read them easier.  These maps are borrowed from The Weather Channel page.

Surface Maps

Surface maps are used to indicate current surface conditions.  These maps usually show fronts, high and low pressure systems, areas of precipitation, temperature and winds.  The following is an example of a surface map.

Different weather maps show different aspects of the weather.  This particular map does not show temperature and winds explicitly, but you can estimate where you may find relatively extreme values.  I will explain what the symbols of this map indicate.

High pressure is shown using a big blue H.  This is indicative of fair weather and relatively light winds.

Low pressure is shown using a big red L.  This is indicative of bad weather and precipitation.

The lines on the map are isobars.  They can help us determine wind speed.  The closer that the isobars are together, the higher the winds will be.  They also help determine wind direction because winds generally blow parallel to isobars.

Precipitation can be seen on weather maps as well.  Usually rain is shown as areas of green, snow as areas of white and mixed precipitation as orange or pink.

Fronts are easy to pick out on weather maps.  There are four main types of fronts, Cold Fronts, Warm Fronts, Stationary Fronts and Occluded Fronts.  Fronts look generally the same on all weather maps.

Cold Fronts are shown as a blue lines with shaded blue triangles extending out in the direction the front is traveling.

Warm Fronts are shown as red lines with shaded red semi-circles extending out in the direction the front is traveling.

Stationary fronts are shown as dashed red and blue lines with shaded blue triangles extending out into the warm side of the front and shaded red semi-circles extending out onto the cold side of the front.

Occluded fronts are shown as a purple line with alternating shaded triangles and semi-circles drawn in the direction the front is traveling.  The front is drawn extending from the point that the warm and cold fronts meet into the low pressure center.

This page was last updated December 11, 2003

Created by cyclonic_vortex@yahoo.com