:Product: 20041104RSGA.txt :Issued: 2004 Nov 04 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 309 Issued at 2200Z on 04 Nov 2004 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity decreased to low levels today. The largest flare of the period was a long duration C6/Sf that occurred at 04/0905Z from Region 696 (N09E19). There was an associated Tenflare (210 sfu's) and a Type IV spectral radio sweep. A partial halo CME was also seen in SOHO/LASCO imagery shortly following this event which appears to have the potential of becoming geoeffective. There was a doubling of the sunspot area coverage and a magnetic delta structure is now visible in the trailing portion of the spot cluster. Region 693 (S15W31) remains impressive in appearance, although there were no recorded flares and some decay was observed during the day. There remains a weak delta structure in the trailing portion of the sunspot complex. Region 691 (N13W94) produced B and C class flares as this region exited the solar west limb. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels. Region 693 and 696 are both capable of producing an isolated major flare activity. IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field was at mostly quiet to unsettled levels today. There was one active period at high latitudes occurring between 03/2100 and 2400Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominantly quiet to unsettled on 05 November. On 06 November the field is expected to see minor to major storming conditions due to the effects of the M5/Sn event that occurred yesterday producing a full halo CME from Region 696. A partial halo CME resulting from the long duration C6/Sf flare that occurred at 04/0905Z is expected to produce minor storming conditions late on the sixth, or early on 7 November. III. Event Probabilities 05 Nov-07 Nov Class M 60/60/60 Class X 20/20/20 Proton 20/20/20 PCAF yellow IV. Penticton 10.7 cm Flux Observed 04 Nov 136 Predicted 05 Nov-07 Nov 135/140/140 90 Day Mean 04 Nov 109 V. Geomagnetic A Indices Observed Afr/Ap 03 Nov 007/010 Estimated Afr/Ap 04 Nov 008/010 Predicted Afr/Ap 05 Nov-07 Nov 012/015-025/030-020/025 VI. Geomagnetic Activity Probabilities 05 Nov-07 Nov A. Middle Latitudes Active 25/40/40 Minor storm 15/35/25 Major-severe storm 05/20/15 B. High Latitudes Active 30/30/35 Minor storm 15/45/40 Major-severe storm 05/20/15