:Product: 19990810RSGA.txt :Issued: 1999 Aug 10 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 222 ISSUED AT 2200Z ON 10 AUG 1999 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 09/2100Z TO 10/2100Z: SOLAR ACTIVITY WAS LOW. REGIONS 8656 (N14W86), 8657 (S31W35), AND 8662 (S16E07) ALL PRODUCED C-CLASS X-RAY EVENTS. REGION 8656 PRODUCED A C4/SF AT 10/0607Z AND CONTINUES TO PRODUCE OCCASIONAL MINOR SUBFLARES. REGION 8662, THE LARGEST AND MOST ACTIVE REGION ON THE VISIBLE DISK, PRODUCED A C4/1F AT 10/1624Z. MINOR GROWTH AND FREQUENT FLUCTUATIONS WERE OBSERVED IN THIS REGION AND MODERATE MAGNETIC COMPLEXITY WAS EVIDENT IN A BETA-GAMMA CONFIGURATION. REMAINING REGIONS WERE QUIET. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO REMAIN LOW. REGION 8662 WILL CONTINUE TO PRODUCE C-CLASS FLARES WITH A SMALL CHANCE OF AN M-CLASS. OCCASIONAL C-CLASS FLARES ARE ALSO EXPECTED FROM REGION 8657. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 09/2100Z TO 10/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. A WEAK DISTURBANCE WAS DETECTED AT L1 AROUND 10/1800Z. BZ TURNED SHARPLY SOUTHWARD CAUSING UNSETTLED CONDITIONS AT MID AND HIGH LATITUDES. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED. III. EVENT PROBABILITIES 11 AUG-13 AUG CLASS M 15/15/15 CLASS X 05/05/05 PROTON 01/01/01 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 10 AUG 127 PREDICTED 11 AUG-13 AUG 130/130/135 90 DAY MEAN 10 AUG 164 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 09 AUG 010/019 ESTIMATED AFR/AP 10 AUG 005/007 PREDICTED AFR/AP 11 AUG-13 AUG 008/007-005/007-005/007 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 11 AUG-13 AUG A. MIDDLE LATITUDES ACTIVE 20/10/10 MINOR STORM 05/01/01 MAJOR-SEVERE STORM 01/01/01 B. HIGH LATITUDES ACTIVE 25/15/15 MINOR STORM 10/05/05 MAJOR-SEVERE STORM 01/01/01