AAVSO Sudden Ionospheric Disturbance Report 
     April 1989
  
     Observers:
     A-01   A-03   A-09   A-19   A-26   
     A-40   A-46   A-49   A-50   A-52   
     A-59   A-60   A-61   A-62   A-63   
     
     YYMMDD      Event Peak (UT)   Importance
     890402         1543                2+ 
     890402         2328                1  
     890403         1519                1+ 
     890403         1931                2  
     890403         2210                2  
     890405         1159                2  
     890405         2310                1+ 
     890407         1315                2  
     890407         1528                2  
     890407         1951                1+ 
     890408         1744                1- 
     890408         1833                2  
     890408         2125                2  
     890412         1408                1  
     890413         1745                1- 
     890413         1806                1  
     890413         1830                2  
     890413         2058                1+ 
     890413         2143                2+ 
     890417         1746                1+ 
     890418         2107                2+ 
     890419         2058                1  
     890420         0531                1+ 
     890420         1415                1+ 
     890420         1518                2+ 
     890421         0443                1  
     890421         1427                2+ 
     890421         1721                1  
     890422         0551                1  
     890422         1301                1  
     890423         1250                1- 
     890423         2155                2+ 
     890424         1300                1  
     890424         1335                1+ 
     890425         1821                1- 
     890425         2204                1+ 
     890427         1717                2  
     *******************************************
     Importance Summary April 1989
        1- events:  4
        1  events:  9
        1+ events:  9
        2  events:  9
        2+ events:  6
        3  events:  0
        3+ events:  0
     Total events:  37