:Product: 19990304RSGA.txt :Issued: 1999 Mar 04 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 063 ISSUED AT 2200Z ON 04 MAR 1999 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 03/2100Z TO 04/2100Z: SOLAR ACTIVITY REMAINED LOW. REGION 8475 (N32W22) PRODUCED A C3/1F AT 03/2343Z AND A C3/SF AT 04/0514Z. REGION 8475 EXHIBITED SLIGHT DECAY. REGION 8476 (N18W34) GREW SLIGHTLY DURING THE PERIOD. HOWEVER, ITS RATE OF EMERGENCE SLOWED. REGION 8471 (N28W63) WAS GENERALLY STABLE. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY SHOULD BE PREDOMINANTLY LOW FOR THE NEXT THREE DAYS. REGIONS 8471, 8475, AND 8476 ARE CAPABLE OF PRODUCING C-CLASS EVENTS. THEY ALSO COULD PRODUCE AN ISOLATED M-CLASS EVENT BUT THAT POSSIBILITY IS DECREASING. PREVIOUSLY ACTIVE LONGITUDES ARE DUE TO RETURN TO THE EAST LIMB NEAR THE END OF THE PERIOD. ACTIVITY LEVELS MAY ELEVATE AT THAT TIME. AN ACCURATE ESTIMATE OF THE FLARE POTENTIAL OF THESE LONGITUDES MUST AWAIT THEIR APPEARANCE AT THE LIMB. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 03/2100Z TO 04/2100Z: THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MINOR STORM LEVELS. AFTER SOLAR WIND VELOCITIES DECREASED ON 03 MAR TO LESS THAN 400 KM/S, THEY BEGAN TO INCREASE AGAIN EARLY ON 04 MAR TO OVER 550 KM/S. DENSITY REMAINED LOW INDICATING A RESURGENCE OF A CORONAL HOLE STREAM IMPACTING THE EARTH. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS REACHED HIGH LEVELS AT 04/1920Z. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD SHOULD BE AT PREDOMINANTLY UNSETTLED TO ACTIVE LEVELS FOR THE NEXT THREE DAYS. ISOLATED MINOR STORMING IS POSSIBLE DURING THAT TIME. THIS FORECAST IS BASED UPON THE CONTINUATION OF A CORONAL HOLE STREAM IMPACTING THE EARTH FROM AN ELONGATED CORONAL HOLE IN THE SOUTHWEST QUADRANT OF THE SUN. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT SHOULD REACH HIGH LEVELS EACH DAY OF THE FORECAST PERIOD. III. EVENT PROBABILITIES 05 MAR-07 MAR CLASS M 25/25/35 CLASS X 05/05/05 PROTON 05/05/05 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 04 MAR 144 PREDICTED 05 MAR-07 MAR 150/158/165 90 DAY MEAN 04 MAR 143 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 03 MAR 011/015 ESTIMATED AFR/AP 04 MAR 020/020 PREDICTED AFR/AP 05 MAR-07 MAR 018/018-015/015-009/009 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 05 MAR-07 MAR A. MIDDLE LATITUDES ACTIVE 30/30/20 MINOR STORM 15/15/10 MAJOR-SEVERE STORM 05/05/05 B. HIGH LATITUDES ACTIVE 35/30/20 MINOR STORM 20/15/10 MAJOR-SEVERE STORM 05/05/05