1.3.2 More on Weather Maps

What can a weather map tell you about the weather?

A lot! A weather map indicates all sorts of things to let you know the forecast. It also may have some cute graphics associated with it.

Weather Maps

You may have seen weather maps like the one pictured below (Figure below). A weather map shows weather conditions for a certain area. The map may show the actual weather on a given day. It may show the predicted weather for some time in the future. Some weather maps show many weather conditions. Others show a single condition.

This weather map shows air pressure contours. Which state has the lowest air pressure shown on the map?

Air Pressure Maps

The weather map pictured below (Figure above) shows air pressure. The lines on the map connect places that have the same air pressure. Air pressure is measured in a unit called the millibar. Isobars are the lines that connect the points with the same air pressure. The map also shows low- and high-pressure centers and fronts. Find the cold front on the map. This cold front is likely to move toward the northeast over the next couple of days. How could you use this information to predict what the weather will be on the East Coast?

Other Weather Maps

Instead of air pressure, weather maps may show other weather conditions. For example, a temperature map might show the high and low temperatures of major cities. The map may have isotherms, lines that connect places with the same temperature.

Vocabulary

isobar: Lines of equal pressure.
isotherms: Lines that connect places with the same temperature.
weather map: Map showing weather conditions over a wide area at a given time.