AAVSO Sudden Ionospheric Disturbance Report
     May 1998

     Observers:
     A-05   A-09   A-50   A-52   A-62
     A-63   A-72   A-80   A-81   A-82
     A-84   A-87

     YYMMDD      Event Peak (UT)   Importance
     980501         1209                1  
     980501         1306                2  
     980501         1456                2  
     980501         1737                2  
     980501         2015                1- 
     980501         2027                2  
     980501         2148                2  
     980501         2240                3  
     980502         1339                2+ 
     980502         2040                3  
     980503         1006                1  
     980503         1832                2+ 
     980503         2121                3  
     980504         1715                1- 
     980504         1829                1- 
     980504         2359                2+ 
     980505         1159                1  
     980505         1626                2  
     980505         1847                1  
     980505         1926                2  
     980505         2001                1  
     980505         2057                2+ 
     980505         2217                2+ 
     980505         2308                1  
     980505         2332                3  
     980506         0706                1- 
     980506         0715                1+ 
     980506         0806                1  
     980506         1340                1+ 
     980506         1840                1+ 
     980507         0740                1- 
     980507         1116                2  
     980507         1332                1- 
     980507         1349                2  
     980507         1455                1+ 
     980507         1624                2  
     980507         2016                1+ 
     980507         2232                1- 
     980507         2256                2  
     980508         1307                2  
     980508         1401                2+ 
     980508         1620                1- 
     980508         2126                2+ 
     980508         2253                2  
     980508         2341                1  
     980509         1039                1  
     980509         1106                1  
     980509         1314                2  
     980509         1419                2+ 
     980509         1735                2  
     980509         2036                2+ 
     980509         2134                1+ 
     980510         0826                2  
     980510         0952                1+ 
     980510         1059                1- 
     980510         1145                1- 
     980510         1317                2  
     980510         1509                1- 
     980510         1931                1+ 
     980511         2146                3  
     980512         1844                1- 
     980513         1455                1- 
     980514         1029                1- 
     980514         1348                1  
     980514         1658                1- 
     980515         1004                1- 
     980516         1556                1  
     980518         2004                2  
     980519         1549                2+ 
     980527         0817                1  
     980527         0918                1  
     980527         1112                1+ 
     980527         1217                1- 
     980527         1325                2+ 
     980527         1818                1  
     980527         1839                2+ 
     980527         2234                2+ 
     980528         0438                1+ 
     980528         0809                1- 
     980528         0853                1  
     980528         0924                1- 
     980528         1037                1- 
     980528         1118                1  
     980528         1254                1- 
     980528         1352                2+ 
     980528         1656                1- 
     980528         1854                2+ 
     980528         2032                1  
     980528         2119                2  
     980529         0105                2  
     980529         1105                1  
     980529         1243                1- 
     980529         1352                1+ 
     *******************************************
     Importance Summary May 1998
        1- events:  23
        1  events:  19
        1+ events:  11
        2  events:  20
        2+ events:  15
        3  events:  5
        3+ events:  0
     Total events:  93