Download Jet Streams A jet stream is a fast moving, narrow river of air in the

Jet Streams
A jet stream is a fast moving, narrow river of air in the upper levels of the atmosphere, typically near
cloud level or just above. Jet streams often travel around the Earth, transporting weather systems from
one place to another. Jet streams typically flow from west to east but often take a meandering path
which can take them briefly southward and northward as well. There are two main types of jet streams:
the polar jet stream and the subtropical jet stream.
Winds in the polar jet stream frequently reach speeds of over 200 mph. The polar jet stream is
commonly located over Canada and frequently takes dips southward into the United States during the
cooler months. This jet stream forms at the barrier between a cold air mass and a warm air mass. That is
where the greatest density of air can be found and as a result the air is squeezed together and moves
faster. The jet stream often marks the separation between warm and cold air, and is where cold fronts
and warm fronts are located. The larger the contrast between cold and warm air, the faster the jet
stream flows. The polar jet stream also pushes storm systems and fronts from one place to another. The
stronger the jet stream, the faster weather systems move.
The subtropical jet stream is found further south, over the southern United States and into the Southern
Pacific and Atlantic Oceans. Because the subtropical jet stream is often located over warm water, it can
move large amounts heat and moisture from place to place. Storms that move across Florida and the
Southeast United States are often related to the subtropical jet stream. When this occurs heavy rain and
thunderstorms are the result.
From time to time, the polar jet stream and subtropical jet stream can overlap in places. When they do,
they often cause storms to intensify dramatically. The subtropical jet stream transports heat and
moisture, while the polar jet stream transports cold air. Big storms such as blizzards can be the result
when everything comes together.
When flying in the same general direction as the jet stream, airplanes will often fly near or inside the
river of air to help move them faster. However, If an airplane flies against the jet stream, it will move
slower and take longer to arrive at its destination.
Questions:
How does a jet stream form?
Jet streams separate cold and warm air. T/F
The polar jet stream is generally slower than the subtropical jet stream. T/F
Jet streams always move from west to east. T/F
A rain storm in Tampa Florida is more likely caused by the subtropical jet stream. T/F
Links:
http://en.wikipedia.org/wiki/Jet_stream
http://www.srh.noaa.gov/jetstream/global/jet.htm
http://uwstudentweb.uwyo.edu/G/GDEFORDE/
http://www.usatoday.com/weather/tg/wjstream/wjstream.htm
http://www.weather.gov/glossary/index.php?word=jet+stream
http://www.theweatherprediction.com/habyhints/100/