:Product: 20031024RSGA.txt :Issued: 2003 Oct 24 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 297 Issued at 2200Z on 24 Oct 2003 IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity has been high. Region 486 (S16E57) produced several flares, including a M7.6/1n at 24/0254 UTC, with an associated Type IV radio sweep. An associated CME was observed on SOHO/LASCO imagery with an estimated velocity of 900 km/s, although the CME did not appear to be earth-directed. Region 484 (N05W15) produced an M1.3 at 24/1856 UTC. Region 484 appears to be decaying slightly, while Region 486 is growing. Both regions continue to exhibit large, complex beta-gamma-delta magnetic configurations. The F10 value is flare enhanced and is estimated due to solar activity at the time of the measurement. IB. Solar Activity Forecast: Solar activity is expected to be high. Regions 484 and 486 are expected to produce major flares. IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to severe storm levels. An interplanetary shock was observed at ACE at 24/1450 UTC, with a subsequent sudden impulse observed at 1530 UTC. The sudden impulse was followed by about two hours of severe geomagnetic storm activity, and produced a magnetopause crossing at GOES 12. Solar wind data show high density flow with strong magnetic fields (about 30 nT), although so far Bz has been strongly northwards. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to severe storm conditions for day one, due to persistence from the current transient-driven activity. Activity should subside to unsettled to minor storm levels on days two and three. III. Event Probabilities 25 Oct-27 Oct Class M 90/90/90 Class X 45/45/45 Proton 15/20/25 PCAF yellow IV. Penticton 10.7 cm Flux Observed 24 Oct 191 Predicted 25 Oct-27 Oct 190/195/200 90 Day Mean 24 Oct 117 V. Geomagnetic A Indices Observed Afr/Ap 23 Oct 005/007 Estimated Afr/Ap 24 Oct 035/040 Predicted Afr/Ap 25 Oct-27 Oct 035/040-030/040-020/030 VI. Geomagnetic Activity Probabilities 25 Oct-27 Oct A. Middle Latitudes Active 30/40/40 Minor storm 40/30/30 Major-severe storm 30/20/15 B. High Latitudes Active 20/20/20 Minor storm 40/40/40 Major-severe storm 40/40/30