:Product: 20010510RSGA.txt :Issued: 2001 May 10 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 130 Issued at 2200Z on 10 May 2001 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been low during the past 24 hours. Two noteworthy C-class events occurred during the day. The first was a C5 which started at 0105 UTC, reached maximum at 0203 UTC, and ended at 0443 UTC. There were no observations of corresponding disk activity, but there was a CME just behind the Northwest limb of the Sun that could be reasonably associated with the event. The other was a C6 with start-max-end times of 1448-1519-1547 UTC: newly assigned Region 9454 (N15E74) was seen to brighten in H-alpha during the event, and a CME became visible on the East limb in C2 observations at 1530 UTC. A type II sweep was also associated with this event. New Region 9454 is now the largest sunspot group on the disk with an area of 300 millionths in an Eao-Beta configuration. IB. Solar Activity Forecast: Solar activity is expected to be mostly low, but there is a chance for an isolated M-class event from Region 9454. IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field ranged from quiet to minor storm levels. An initially active geomagnetic field reached minor storm levels between 0000-0900 UTC. Conditions declined thereafter and were quiet to unsettled during the last nine hours of the day. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled during the next three days. III. Event Probabilities 11 May-13 May Class M 20/20/20 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 10 May 130 Predicted 11 May-13 May 135/135/135 90 Day Mean 10 May 168 V. Geomagnetic A Indices Observed Afr/Ap 09 May 019/032 Estimated Afr/Ap 10 May 028/035 Predicted Afr/Ap 11 May-13 May 015/015-010/010-010/010 VI. Geomagnetic Activity Probabilities 11 May-13 May A. Middle Latitudes Active 35/30/30 Minor storm 25/20/20 Major-severe storm 10/05/05 B. High Latitudes Active 30/25/25 Minor storm 30/25/25 Major-severe storm 15/10/10