:Product: 20000725RSGA.txt :Issued: 2000 Jul 25 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 207 ISSUED AT 2200Z ON 25 JUL 2000 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 24/2100Z TO 25/2100Z: SOLAR ACTIVITY HAS BEEN HIGH. REGION 9097 (N08W15), CURRENTLY THE LARGEST GROUP ON THE DISK, PRODUCED AN M8/2B FLARE AT 0249Z WHICH WAS ACCOMPANIED BY TYPE II AND TYPE IV RADIO SWEEPS. AN ASSOCIATED FAINT HALO CME WAS OBSERVED BY LASCO, BEGINNING AT 0330Z. THIS REGION PRODUCED AN ADDITIONAL M-CLASS EVENT: AN M1/1B AT 1846Z. REGION 9087 (S10W80) PRODUCED AN M3/2N AT 0456Z. THE GROUP CONTINUES TO BE A LARGE, F-TYPE REGION AS IT APPROACHES WEST LIMB. SOME GROWTH WAS NOTED IN REGION 9090 (N15W48) BUT THE GROUP COULD ONLY MUSTER A C6/SN FLARE AT 1241Z. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE MODERATE, WITH REGIONS 9087, 9097, AND 9090 BEING THE MOST LIKELY SOURCES FOR M-CLASS FLARES. THERE IS A CHANCE FOR AN ISOLATED X-CLASS OR PROTON PRODUCING FLARE DURING THE NEXT THREE DAYS. IIA. GEOPHYSICAL ACTIVITY SUMMARY 24/2100Z TO 25/2100Z: THE GEOMAGNETIC FIELD HAS BEEN QUIET TO UNSETTLED. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED WITH POSSIBLE ACTIVE PERIODS DURING THE NEXT 24 HOURS. AN INCREASE MAY OCCUR IF EFFECTS FROM THE CME OF 24 JULY MATERIALIZE. MOSTLY UNSETTLED CONDITIONS SHOULD PREVAIL ON THE SECOND DAY, AND AN INCREASE TO ACTIVE (WITH POSSIBLE MINOR-TO- MAJOR STORM PERIODS) IS EXPECTED SOMETIME ON THE THIRD DAY. THIS INCREASE IS PREDICTED BECAUSE OF THE HALO CORONAL MASS EJECTION MENTIONED IN PART IA. III. EVENT PROBABILITIES 26 JUL-28 JUL CLASS M 75/70/65 CLASS X 25/25/20 PROTON 25/25/20 PCAF YELLOW IV. PENTICTON 10.7 CM FLUX OBSERVED 25 JUL 202 PREDICTED 26 JUL-28 JUL 190/190/190 90 DAY MEAN 25 JUL 190 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 24 JUL 004/008 ESTIMATED AFR/AP 25 JUL 007/007 PREDICTED AFR/AP 26 JUL-28 JUL 012/020-010/015-020/025 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 26 JUL-28 JUL A. MIDDLE LATITUDES ACTIVE 20/20/30 MINOR STORM 10/10/25 MAJOR-SEVERE STORM 05/05/20 B. HIGH LATITUDES ACTIVE 30/30/30 MINOR STORM 15/15/25 MAJOR-SEVERE STORM 05/05/25