Upper Level Wind Analysis Charts

Question 1

State the 4 standard constant pressure levels and their altitudes in the standard atmosphere

Answer 1

850 hpa = 5000’
700 hpa = 10 000’
500 hpa = 18 000’
250 hpa = 34 000’

Question 2

State Buys Ballot’s law for the wind on upper level charts

Answer 2

With your back to the wind, low heights are to your left in Northern hemisphere

Question 3

What is the relationship between contour spacing and wind speed on constant pressure charts?

Answer 3

Closeness of contours indicates slope of pressure surface. Close = steep, strong pressure gradient, strong wind. Wide = shallow slope, weak pressure gradient, weak wind.

Question 4

True or False:

The 500 hpa chart has isotherms plotted on it

Answer 4

False

Question 5

True or False:

The only chart with isotachs is the 250 hpa charts

Answer 5

True

Question 6

True or False:

The contour spacing on all upper air charts is 6 decameters

Answer 6

False

Question 7

True or False:

The values of contours on upper air charts are above mean seal level

Answer 7

True

Question 8

True or False:

The 500hpa surface is ALWAYS 18 000’

Answer 8

False

Question 9

A contour labeled as 144 on a 850hpa is…

Answer 9

144 decameters above sea level