:Product: 20001005RSGA.txt :Issued: 2000 Oct 05 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 279 Issued at 2200Z on 05 Oct 2000 IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity was low. Today's largest event was a C2/1f flare at 0613Z from Region 9172 (N13W73). Region 9173 (S13W68) is currently the largest region on the disk but is stable and in a state of slow decline. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field ranged from active to severe storm levels (estimated Kp of 7). A strong shock was observed at the ACE spacecraft at 0241Z, and was followed by transient flow with enhanced density, speed, and magnetic fields. Major to severe storming at all latitudes began after 0300Z. There were two intervals of strongly negative Bz: the first was from 0504-0543Z with Bz values reaching -27 nT and the second was from 0958-1119Z with Bz values reaching -23 nT. Severe (estimated Kp of 7) levels were seen at high latitudes from 0300-1500Z and mid-latitudes also attained the K=7 level from 0600-0900Z. The disturbance appeared to be subsiding during the last three hours of the day. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to minor storm levels during the next 24 hours as the current disturbance subsides. Unsettled to active conditions should follow on the 2nd day, and predominantly unsettled levels are expected by day three. III. Event Probabilities 06 Oct-08 Oct Class M 30/30/30 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 05 Oct 174 Predicted 06 Oct-08 Oct 170/160/150 90 Day Mean 05 Oct 184 V. Geomagnetic A Indices Observed Afr/Ap 04 Oct 025/045 Estimated Afr/Ap 05 Oct 075/085 Predicted Afr/Ap 06 Oct-08 Oct 025/035-015/015-012/010 VI. Geomagnetic Activity Probabilities 06 Oct-08 Oct A. Middle Latitudes Active 25/35/20 Minor storm 50/30/15 Major-severe storm 20/05/05 B. High Latitudes Active 25/35/25 Minor storm 45/30/20 Major-severe storm 25/10/05