:Product: 20010509RSGA.txt :Issued: 2001 May 09 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 129 Issued at 2200Z on 09 May 2001 IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: Solar activity was low during the past 24 hours. Region 9445 (N25W67) produced both of today's C1/Sf flares, the first at 0603 UTC and the second at 0853 UTC. The other active regions on the disk were quiet and stable. A new region emerged at S08W28 and was assigned as Region 9453. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low during the next three days. There is a slight chance, however, for an isolated M-class event from Region 9445. IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field ranged from unsettled to minor storm levels during the past 24 hours. Enhanced solar wind velocity, and periods of sustained southward solar wind magnetic field orientation led to an increase in geomagnetic activity. The plasma and field parameters appear to be consistent with the passage of an interplanetary transient. Minor storm periods were observed from 0000-0600 UTC, and active conditions dominated most of the remainder of the day. The greater than 10 MeV proton event that began at 07/1915 UTC ended at 08/1935 UTC. The peak of the event was 30 pfu at 08/0755 UTC. The greater than 2 MeV electron fluxes attained high levels briefly during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to slightly active during the next 12-24 hours as the current disturbance is likely to persist. Predominantly unsettled levels are expected to prevail during the second and third days. III. Event Probabilities 10 May-12 May Class M 20/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 09 May 129 Predicted 10 May-12 May 125/120/115 90 Day Mean 09 May 168 V. Geomagnetic A Indices Observed Afr/Ap 08 May 016/014 Estimated Afr/Ap 09 May 028/035 Predicted Afr/Ap 10 May-12 May 015/015-010/010-010/010 VI. Geomagnetic Activity Probabilities 10 May-12 May A. Middle Latitudes Active 30/25/25 Minor storm 25/20/20 Major-severe storm 15/10/10 B. High Latitudes Active 30/20/30 Minor storm 25/15/15 Major-severe storm 20/15/10