:Product: 20040109RSGA.txt :Issued: 2004 Jan 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 009 Issued at 2200Z on 09 Jan 2004 IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: Solar activity was moderate during the last 24 hours. Region 537 (N05E37) produced back-to-back M-class flares, an M1 at 0122 UTC followed immediately by an M3 at 0144 UTC. The x-ray events were associated with a narrow CME erupting off the southeast solar limb. Region 537 continues to have a delta configuration and is growing slowly, The spots appeared to be rotating slightly in a counter-clockwise direction. Region 536 (S12W28) is still the largest group on the disk and is undergoing a net loss of total spot area. However, there is some opposite polarity flux emerging just to the east of the region, and the spot group did produce occasional small flares throughout the day. IB. Solar Activity Forecast: Solar activity is expected to be predominantly moderate. There continues to be a slight chance for major flare activity from Region 536 and from Region 537. IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field was at unsettled to minor storm levels during the past 24 hours. An initially unsettled geomagnetic field became more disturbed after 0600 UTC, with one minor storm period from 0600-0900 UTC, followed by unsettled to active conditions for the rest of the day. The increase was likely due to an observed change in the character of the solar wind around 0500 UTC. ACE solar wind data showed a slow rise in velocity, temperature, and density, as well as an increase in the total magnetic field intensity for about 4.5 hours accompanied by moderately southward Bz. The spiral angle also went through a reversal from away to towards just after 0600 Z and back from towards to away around 1000Z. This may be indicative of passage through an interplanetary current sheet. After 1000Z, velocity and speed continued to rise along with temperature, possibly suggestive of the onset of a co-rotating interaction region. The greater than 2 MeV electron fluxes were at high levels during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled with occasional active periods over the next three days. The main driver for this enhanced activity is expected to be the continued presence of high speed solar wind originating from a solar coronal hole. III. Event Probabilities 10 Jan-12 Jan Class M 75/75/75 Class X 15/15/15 Proton 10/10/10 PCAF yellow IV. Penticton 10.7 cm Flux Observed 09 Jan 118 Predicted 10 Jan-12 Jan 120/125/125 90 Day Mean 09 Jan 137 V. Geomagnetic A Indices Observed Afr/Ap 08 Jan 004/009 Estimated Afr/Ap 09 Jan 020/025 Predicted Afr/Ap 10 Jan-12 Jan 015/015-015/015-015/020 VI. Geomagnetic Activity Probabilities 10 Jan-12 Jan A. Middle Latitudes Active 35/35/35 Minor storm 20/20/20 Major-severe storm 10/10/10 B. High Latitudes Active 25/25/25 Minor storm 35/35/35 Major-severe storm 15/15/15