:Product: 20010425RSGA.txt :Issued: 2001 Apr 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 115 Issued at 2200Z on 25 Apr 2001 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been moderate. Region 9433 (N16W15) produced two M-class flares during the period. The largest was an M2/2n at 25/1348 UTC. This event had an associated Type II radio sweep and a 200 sfu 10 cm radio burst. A coronal mass ejection (CME) was also observed during this event, however images from the LASCO/EIT space craft show it to be non earth-directed. Region 9433 continued to grow in area and spot count during the period and retains an F-type spot group with a beta-gamma-delta magnetic configuration. Regions 9438 (S13E22) and 9439 (S22W28) were numbered during the period. IB. Solar Activity Forecast: Solar activity is expected to be moderate to high. The ongoing development of Region 9433 suggests a major flare is possible sometime during the forecast period. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was quiet to unsettled. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at quiet to unsettled conditions barring an earth-directed CME. There is an increasing chance for a proton event as Region 9433 continues to evolve and rotate into the western solar hemisphere. III. Event Probabilities 26 Apr-28 Apr Class M 80/80/80 Class X 25/25/25 Proton 20/20/20 PCAF yellow IV. Penticton 10.7 cm Flux Observed 25 Apr 194 Predicted 26 Apr-28 Apr 200/210/215 90 Day Mean 25 Apr 167 V. Geomagnetic A Indices Observed Afr/Ap 24 Apr 011/008 Estimated Afr/Ap 25 Apr 010/008 Predicted Afr/Ap 26 Apr-28 Apr 010/020-010/010-010/010 VI. Geomagnetic Activity Probabilities 26 Apr-28 Apr A. Middle Latitudes Active 10/10/10 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor storm 10/10/10 Major-severe storm 01/01/01