:Product: 19980212RSGA.txt :Issued: 1998 Feb 12 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force. # JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY SDF NUMBER 043 ISSUED AT 2200Z ON 12 FEB 1998 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 11/2100Z TO 12/2100Z: SOLAR ACTIVITY WAS VERY LOW. NUMEROUS B-CLASS X-RAY BURSTS OCCURRED, FOUR OF WHICH WERE OPTICALLY ASSOCIATED WITH SUBFLARES FROM REGION 8156 (S24E43). REGION 8156 CONTINUED TO DISPLAY MINOR GROWTH IN SPOT COUNT AND FIELD INTENSITY. NO NEW REGIONS WERE NUMBERED. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE VERY LOW TO LOW. REGION 8156 MAY PRODUCE C-CLASS SUBFLARES. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z: THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS DURING MOST OF THE PERIOD. HOWEVER, FIELD ACTIVITY INCREASED TO ACTIVE TO MINOR STORM LEVELS DURING 12/0000-0300UT AND 12/1100-1300UTWITH THE MINOR STORM LEVELS LIMITED TO HIGH LATITUDES. THE GREATER THAN 2 MEV ELECTRON FLUX REACHED HIGH LEVELS AT 12/1722UT. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED DURING MOST OF THE PERIOD. HOWEVER, ACTIVE PERIODS ARE POSSIBLE DURING THE LAST TWO DAYS OF THE FORECAST PERIOD. THE GREATER THAN 2 MEV ELECTRON FLUX IS EXPECTED TO BE AT MODERATE TO HIGH LEVELS. III. EVENT PROBABILITIES 13 FEB-15 FEB CLASS M 10/10/05 CLASS X 01/01/01 PROTON 01/01/01 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 12 FEB 091 PREDICTED 13 FEB-15 FEB 094/094/094 90 DAY MEAN 12 FEB 096 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 11 FEB 010/013 ESTIMATED AFR/AP 12 FEB 010/010 PREDICTED AFR/AP 13 FEB-15 FEB 010/010-010/008-010/008 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 13 FEB-15 FEB A. MIDDLE LATITUDES ACTIVE 10/20/20 MINOR STORM 01/05/05 MAJOR-SEVERE STORM 01/01/01 B. HIGH LATITUDES ACTIVE 15/25/25 MINOR STORM 01/10/10 MAJOR-SEVERE STORM 01/01/01