• Weather forecasting began in the mid 1800’s when basic tools, like
the thermometer and barometer, were invented
• Global Weather Reporting
• Weather observations at stations around the world
• Records temperature and pressure every few hours
• Also measure precipitation, surface wind direction and speed, and the
type and amount of cloud cover.
• World Weather Watch
• A program designed to promote the rapid exchange of weather
information
• Helps developing countries establish or improve their meteorological
services
• Offers advice on the effect of weather on natural resources and on
human activities
• All data collected is
transferred to weather maps
• Allows meteorologists to
understand the current weather
and to predict future weather
events
• Uses symbols and colors to
indicate certain characteristics
• Station model: a pattern of
meteorological symbols that
represents the weather at a
particular observing station
and that is recorded on a
weather map
• Examples of data used
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Cloud cover
Wind speed & direction
Types of precipitation
Storm activity
Air temperature
Dew point
• Scientists use lines on
weather maps to connect
points of equal
measurement.
• Lines that connect points of
equal temperature are
called isotherms
• Lines that connect points of
equal atmospheric pressure
are called isobars
• The spacing and shape of the
isobars help meteorologists
interpret their observations
about the speed and direction
of wind
• Closely spaced bars indicate a
rapid change in pressure and high
wind speeds
• Widely spaced isobars generally
indicate a gradual change in
pressure and low wind speeds
• Isobars that form circles indicate
centers of high or low air
pressure
• Marked with an H (high) or an L
(low)
• Weather maps are used to
illustrate many different
features
• Isobars
• Highs and lows in pressure
• Fronts
• Warm, cold, occluded, stationary
• Conditions
• Precipitation
• Direction of air flow