El-Nino and La-Nina
Precipitation

Directions:  Using the Internet, study the table of precipitation and average daily temperature to help answer the following questions.  Your teacher has the web site address.

1) An El-Nino occurred during the years of 1982-1983 and 1991-1992; a La-Nina occurred during 1988-1989.  Based upon the information in the tables, what happens to the precipitation amounts in the cities of Minneapolis, Los Angeles, and New Orleans during these times?
 
 
 
 

2) Find the total precipitation for the three cities (in inches) between these months.  These dates approximate the most intense times of either an El-Nino or a La-Nina.
 
_
Minneapolis
Los Angeles
New Orleans
July 1982 - June 1983 _ _ _
June 1988 - May 1989 _ _ _
Sept. 1991 - August 1992 _ _ _

3) What is the normal yearly precipitation (in inches) for these cities?
 
 
Minneapolis:  Los Angeles:  New Orleans:
 

4) Based on the above information, how does an El-Nino and/or a La-Nina effect precipitation amounts in the three cities?
 
 
 
 
5) For April, 1983, how many inches above average was the precipitation in each city?
 
Minneapolis: Los Angeles: New Orleans:
 

6) What percentage of average was the precipitation for each city in this month?
 
Minneapolis: Los Angeles: New Orleans:
 
 
 
 

7) In what year and by how much was the amount of precipitation in each city off from the average (be sure to indicate if the amount was above average or below average)?

Minneapolis:

Los Angeles:

New Orleans:

Extension Exercises:
1) On a separate sheet of paper (or on the computer), create a line graph: the horizontal axis should represent the months of the year, the vertical axis the amount of precipitation in inches.  Choose one city: either Minneapolis, Los Angeles, or New Orleans.  Graph three different lines: one representing the amount of precipitation for each month during 1983, one representing the amount of precipitation for each month during 1988, and one representing the normal precipitation amounts for each month.

2) Check your answers from question #4 about precipitation from another El-Nino or La-Nina year for the above cities.  Your teacher has the web site addresses for the years of other El-Nino and La-Nina occurrences.

3) Check your answers from question #4 using other cities in the United States.  The links on the bottom of the Monthly Temperature and Precipitation Totals page contains this information for several weather stations across the United States.