Geography 103:  Weather

Exercise 5.  The 18000 ft temperatures, pressures and winds.

 

The maps below show the pressures, temperatures and winds at a height of 18000 ft, for January 13, 2004.  These were printed from the web site weather.unisys.com.  Go to this site to find instructions for reading and interpreting these.  (Note - Both maps show the same data.  In some cases it is easier to read data on the white background (top plot), in other cases - on the black background.)

 

Please use the data sheet to answer the questions following.

 

What height in meters does 18000 ft correspond to?

 

For each weather station three numbers are given.  Two on the left of the “dot”, one on the right.  What does the number on the right tell us?

 

Mark the location of Los Angeles.  What is the approximate pressure at this height for Los Angeles?

 

Mark the location of Seattle.  What is the approximate pressure at this height for Seattle?

 

Mark the location of Boston.  What is the approximate pressure at this height for Boston?

 

Where are the pressures greatest - at the top (north) or the bottom (south)?

 

For each weather station three numbers are given.  Two on the left of the “dot”, one on the right.  What do the two numbers on the left tell us?  What are the units (or, how should we read this)?

 

What is the approximate temperature at this height in Los Angeles?

 

What is the approximate temperature at this height in Seattle?

 

What is the approximate temperature at this height in Boston?

 

What do the yellow contours show?

 

Where is it warmer at this height, at the top (north) or bottom (south)?

 

Do warmer temperatures correspond to high or low pressures at this height?

 

What does the blue shaded area show?

 

What wind speed corresponds to the first (lowest) level of shading?

 

What is the wind speed at this height in Boston?

 

By looking at the blue shading, what is the wind speed over most of the Great Lakes area?

 

In very general terms, over which part of the U.S. is the wind strongest?