:Product: 20010421RSGA.txt :Issued: 2001 Apr 21 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 111 Issued at 2200Z on 21 Apr 2001 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been low. The largest flare was a C8 x-ray burst that occurred at 20/2134 UTC. No optical flare reports were received but space-based images identify Region 9433 (N16E40) as the source. Regions 9436 (S11E72) and 9437 (N08E76) were numbered. IB. Solar Activity Forecast: Solar activity is expected to be moderate. Region 9433 is expected to be the source of most activity. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to active. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled. III. Event Probabilities 22 Apr-24 Apr Class M 75/75/75 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Apr 191 Predicted 22 Apr-24 Apr 200/210/220 90 Day Mean 21 Apr 165 V. Geomagnetic A Indices Observed Afr/Ap 20 Apr 005/008 Estimated Afr/Ap 21 Apr 010/008 Predicted Afr/Ap 22 Apr-24 Apr 005/010-010/010-010/010 VI. Geomagnetic Activity Probabilities 22 Apr-24 Apr A. Middle Latitudes Active 20/20/20 Minor storm 10/10/10 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor storm 10/10/10 Major-severe storm 01/01/01