:Product: 20031017RSGA.txt :Issued: 2003 Oct 17 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 290 Issued at 2200Z on 17 Oct 2003 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was very low. Today's largest flares were a B9 at 0701 UTC from newly numbered Region 482 (N16E62), and a long-duration B8 at 0932 UTC from behind east limb at about N03. Newly numbered Region 481 (S08W17) emerged on the disk today. Solar imagery suggests that there are additional active regions close to east limb which will be rotating into view soon. IB. Solar Activity Forecast: Solar activity is expected to be very low to low. There is a fair chance for an isolated C-class flare sometime during the next three days. IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field ranged from quiet to minor storm levels. The earth continues to be under the influence of a high-speed solar wind stream. The stream continues to decline slowly as the initial speeds around 560 km/s decreased down to about 520 km/s by the end of the period. The interplanetary magnetic field showed regular oscillations and had a weakly negative Bz component on average during the past 24 hours. 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 to active for the next 24 hours. Unsettled levels are expected to prevail for the second and third days. III. Event Probabilities 18 Oct-20 Oct Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 17 Oct 099 Predicted 18 Oct-20 Oct 105/110/110 90 Day Mean 17 Oct 116 V. Geomagnetic A Indices Observed Afr/Ap 16 Oct 016/026 Estimated Afr/Ap 17 Oct 020/025 Predicted Afr/Ap 18 Oct-20 Oct 015/020-010/015-010/015 VI. Geomagnetic Activity Probabilities 18 Oct-20 Oct A. Middle Latitudes Active 35/30/30 Minor storm 20/15/15 Major-severe storm 10/05/05 B. High Latitudes Active 35/35/35 Minor storm 30/25/25 Major-severe storm 25/15/15