:Product: 20010330RSGA.txt :Issued: 2001 Mar 30 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 089 Issued at 2200Z on 30 Mar 2001 IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: Solar activity has been moderate to high. Region 9393 (N17 W30) has produced three M-class flares since 30/0000 UTC. The region remains large, complex, and threatening to produce more Class X events. IB. Solar Activity Forecast: Solar activity is expected to remain high. Region 9393 remains the center of a complex likely to produce M-Class events with a very good chance of one or more Class X events over the next three days as the region moves away from central meridian but remains in a prime location to produce strong to severe effects at Earth. Over a dozen sunspot groups are visible and may produce Class M events. IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: Activity in the geomagnetic field has been unsettled the past 24 hours. Some discontinuity was observed at the ACE spacecraft and at Earth between 30/1800 UTC and 30/1900 UTC. The event appeared to be small and is likely the result of solar activity prior to 29 March. The small proton event that began at 29/1000 UTC reached a maximum flux of 35 pfu in the >30 MeV GOES detector and remains above 10 pfu today. IIB. Geophysical Activity Forecast: Effects from CME's from the events on 29 March are expected to begin early on 31 March. Model runs predict an earlier arrival at Earth late on 30 March. ACE energetic protons are rising slowly indicating the disturbance is still some distance away at 30/2100 UT. Any geomagnetic storm that results is expected to range from minor to major. The small >30 MeV proton event in progress is expected to continue its slow decline with a chance of an enhancement with the passage of the interplanetary shock. Major activity from Region 9393 may well produce additional proton events and geomagnetic activity at Earth. III. Event Probabilities 31 Mar-02 Apr Class M 80/80/80 Class X 35/35/35 Proton 99/30/30 PCAF yellow IV. Penticton 10.7 cm Flux Observed 30 Mar 257 Predicted 31 Mar-02 Apr 255/250/245 90 Day Mean 30 Mar 163 V. Geomagnetic A Indices Observed Afr/Ap 29 Mar 017/022 Estimated Afr/Ap 30 Mar 014/015 Predicted Afr/Ap 31 Mar-02 Apr 045/050-045/050-025/030 VI. Geomagnetic Activity Probabilities 31 Mar-02 Apr A. Middle Latitudes Active 05/05/30 Minor storm 40/40/17 Major-severe storm 52/50/50 B. High Latitudes Active 10/10/30 Minor storm 40/40/30 Major-severe storm 50/50/35