:Product: 19980118RSGA.txt :Issued: 1998 Jan 18 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 018 ISSUED AT 2200Z ON 18 JAN 1998 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 17/2100Z TO 18/2100Z: SOLAR ACTIVITY WAS VERY LOW. REGION 8136 (N16W51) PRODUCED A B3/SF AT 18/1153Z. THE REMAINING ACTIVITY WAS LIMITED TO OCCASIONAL OPTICALLY UNCORRELATED B-CLASS FLARES. REGION 8131 (S23W74) CONTINUES TO DECAY AS IT NEARS THE WEST LIMB. IT IS NOW A FIVE SPOT CAO GROUP MEASURING 180 MILLIONTHS IN WHITE LIGHT AREA. THE REMAINING REGIONS HAVE BEEN QUIET. SPACE-BASED CORONAGRAPH IMAGERY INDICATED A HALO CORONAL MASS EJECTION (CME) OCCURRED NEAR THE EAST LIMB AROUND 17/0600Z. THE MATERIAL APPEARS TO BE FLOWING FROM BEHIND THE LIMB THUS MOSTLY EASTWARD DIRECTED. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO REMAIN VERY LOW. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z: THE GEOMAGNETIC FIELD WAS QUIET UNTIL AROUND 18/0700Z WHEN PERIODS OF UNSETTLED TO ACTIVE CONDITIONS OCCURRED. NORTHERN LATITUDES EXPERIENCED PERIODS OF MINOR STORMING. THE DISTURBANCE ENDED AT ABOUT 18/1600Z AND CONDITIONS HAVE BEEN QUIET SINCE. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN AT MOSTLY QUIET LEVELS. III. EVENT PROBABILITIES 19 JAN-21 JAN CLASS M 10/10/10 CLASS X 01/01/01 PROTON 01/01/01 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 18 JAN 095 PREDICTED 19 JAN-21 JAN 095/096/097 90 DAY MEAN 18 JAN 096 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 17 JAN 004/005 ESTIMATED AFR/AP 18 JAN 010/005 PREDICTED AFR/AP 19 JAN-21 JAN 005/005-005/005-005/005 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 19 JAN-21 JAN A. MIDDLE LATITUDES ACTIVE 10/10/10 MINOR STORM 01/01/01 MAJOR-SEVERE STORM 01/01/01 B. HIGH LATITUDES ACTIVE 15/15/15 MINOR STORM 05/05/05 MAJOR-SEVERE STORM 01/01/01