:Product: Report of Solar-Geophysical Activity :Issued: 2000 Mar 21 2229 UT # 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 081 ISSUED AT 2200Z ON 21 MAR 2000 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 20/2100Z TO 21/2100Z: SOLAR ACTIVITY WAS MODERATE. AN UNOBSERVED M1 X-RAY EVENT OCCURRED AT 1424Z, WITH ASSOCIATED TYPE II SWEEP. FLARE ACTIVITY WAS SOMEWHAT SUPPRESSED, AS MOST OF THE DISK REGIONS WERE EITHER STABLE OR DECAYING. REGION 8910 (N12W49) IS STILL DOMINANT IN WHITE LIGHT AND H-ALPHA. NEWLY NUMBERED REGION 8922 (N14E57) ROTATED FULLY INTO VIEW. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGION 8910 IS THE BEST CANDIDATE FOR ISOLATED M-CLASS FLARES. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 20/2100Z TO 21/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED THROUGHOUT THE PERIOD, THERE IS A CHANCE FOR SOMEWHAT ELEVATED ACTIVITY VERY LATE IN THE INTERVAL, WHEN A CORONAL HOLE ROTATES TO A POTENTIALLY GEO-EFFECTIVE POSITION. III. EVENT PROBABILITIES 22 MAR-24 MAR CLASS M 50/50/50 CLASS X 05/05/05 PROTON 05/05/05 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 21 MAR 231 PREDICTED 22 MAR-24 MAR 235/240/245 90 DAY MEAN 21 MAR 175 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 20 MAR 005/008 ESTIMATED AFR/AP 21 MAR 003/005 PREDICTED AFR/AP 22 MAR-24 MAR 010/015-010/010-015/015 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 22 MAR-24 MAR A. MIDDLE LATITUDES ACTIVE 10/10/20 MINOR STORM 01/01/05 MAJOR-SEVERE STORM 01/01/01 B. HIGH LATITUDES ACTIVE 15/15/30 MINOR STORM 05/05/10 MAJOR-SEVERE STORM 01/01/01