Ways to Depict Weather Data

Television Weather Forecasts

Weather data for television in the U.S. is provided by the National Weather Service using simple open list form and simplified, large, interactive computer maps, covered with symbols and color coded. Days are shown with pictures of weather forms, such as a sun or a black cloud, with the temperature underneath in list form. Large, visual, interactive maps show the U.S. or a single state with its temperature, while specific weather types, such as precipitation, wind, fog, humidity and cloud, are shown in separate weather maps by shades of color, accompanied often by a color index. Different weather is depicted by a certain color: precipitation by shades of blue; temperature as blue and purple (cold) to red (hot); and wind as blue (weak) to red (strong). Arrows and curved lines showing flow and direction are added to wind, fronts and stream maps.

Catastrophic weather events incur special live updates. Updates use dynamic satellite and radar maps to keep analysts and viewers fully updated minute by minute. Special weather events are displayed on line graphs and color maps for tracking and comparing year-long activity. Graphs will usually be line graphs not bar graphs, tracking levels of intensity from month to month to compare. State and national tornado maps use dots of color representing the enhanced Fujita scale from 0 to 5, accompanied by a color index.

Live satellite footage is particularly useful in analyzing and broadcasting storm front activity. The map visuals are dynamic, although not live. Satellite and radar map displays show direction, location and intensity of weather patterns. Data is transformed into visual lines, curves, color and arrows with little or no numbers. For example, infrared satellite footage of cloud top temperature, a key indicator of cloud height, may be depicted with a color index from gray (warmer) to pink (colder), contrary to normal humidity and temperature color ranges.

Maps are used for dynamic, changing weather display. Graphs are useful for comparative historical data, but lists provide a static presentation of weather. The benefit of lists is their quick view appeal to viewers; they do not require interpreting map indexes and symbols. The reliability of data will depend on how often data is updated.