WW2010
University of Illinois

WW2010
 
welcome
 
online guides
 
archives
 
educational cd-rom
 
current weather
 
about ww2010
 
index

Online Guides
 
introduction
 
meteorology
 
remote sensing
 
reading maps
 
projects, activities

Meteorology
 
introduction
 
air masses, fronts
 
clouds, precipitation
 
el nino
 
forces, winds
 
hurricanes
 
hydrologic cycle
 
light, optics
 
midlatitude cyclones
 
severe storms
 
weather forecasting

Midlatitude Cyclones
 
introduction
 
definition
 
associated winds
 
air masses
 
on satellite images
 
upper air features

Upper Air Features
 
geopotential height
 
troughs
 
ridges
 
wave amplification
 
rising motion
 
steering level
 
jet stream
 
jet streaks
 
vertical motions
 
mid-level moisture
 
wind vectors

User Interface
 
graphics
text

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Jet Stream
current of rapidly moving air

The jet stream is a current of fast moving air found in the upper levels of the atmosphere. This rapid current is typically thousands of kilometers long, a few hundred kilometers wide, and only a few kilometers thick. Jet streams are usually found somewhere between 10-15 km (6-9 miles) above the earth's surface. The position of this upper-level jet stream denotes the location of the strongest SURFACE temperature contrast (as in the diagram below).

[Image: jet stream schematic (28K)]


During the winter months, Arctic and tropical air masses create a stronger surface temperature contrast resulting in a strong jet stream. However, during the summer months, when the surface temperature variation is less dramatic, the winds of the jet are weaker.

Below is an ETA Model forecast panel for 300 mb winds and geopotential heights (white contours). The color filled regions indicate wind speed in knots and is color coded according to the legend at the bottom of the image. The shades of blue indicate winds less than 60 knots, while winds greater than 120 knots are given in shades of red.

[Image: jet stream example (47K)]


The yellow, green and red ribbon on the image above represents the jet stream, and along the East Coast, the region of strongest winds (shaded in red) is a jet streak.



steering level
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

jet streaks