Unit 15


Unit Overview

This unit examines the instruments, data, and skills required to perform accurate weather tracking and forecasting. The main sections are as follows:

  • Weather data acquisition
  • Mapping weather data
  • Weather forecasting

Although it is not an inherent part of the sub-discipline of physical geography, weather forecasting involves many of the tools that physical geographers use, and, for the most part, the general public is well aware of it.

Weather forecasting could not be practiced with much confidence without meteorological data. These data are acquired at manned and unmanned weather stations equipped with thermometers, barometers, rain gauges, hygrometers, weather vanes, and anemometers. Not only are surface data necessary for forecasting, but also upper-air data are also very important. Upper-atmospheric processes are related to surface processes. Satellites also acquire meteorological data.

Unit Objectives

  • To discuss the general network of weather stations and the types of data collected from each
  • To illustrate typical weather maps compiled from weather data and to provide some elementary interpretations of them
  • To outline weather forecasting methods and comment on their formulation and reliability

Glossary of Key Terms

Geosynchronous satellite Satellite whose revolution of the Earth is identical to the planet's rotational speed; therefore, the satellite is "fixed" in a stationary position above the same point on the Earth's surface.
Numerical weather prediction The computer weather forecasting method used by the National Weather Service, based on projections by small increments of time up to 48 hours into the future.
Polar orbit Longitudinal orbits that repeatedly pass close to both poles, surveying a different, complete meridional segment of the surface during each revolution.
Radiosonde Radio-equipped weather instrument packages that are carried aloft by balloon.
Synoptic weather chart A map of weather conditions covering a wide geographic area at a given moment in time.

Unit Outline

  • Weather data acquisition
    • Weather stations
      • instrumentation
      • synoptic weather chart
      • radiosondes
      • rawinsonde observations
    • Weather satellites
      • geosynchronous orbits
  • Mapping weather data
    • The surface weather map
      • open-wave cyclone
      • storm track
    • The upper-air weather map
      • correspondence between the upper air and surface conditions
  • Weather Forecasting
    • The forecasting industry
      • numerical weather prediction
      • National Weather Service
      • American Meteorological Society
    • Long-range forecasting
      • 30- and 90-day forecasts for temperature and precipitation, error rate high

Review Questions

  1. List the types of symbols used for representing ongoing precipitation, wind direction, wind speed, and isobars on weather maps.
  2. What is a geosynchronous satellite, and approximately how much of the Earth's surface can it monitor?
  3. Briefly describe the process of numerical weather prediction, used by the National Weather Service.