:Product: 20021018RSGA.txt :Issued: 2002 Oct 18 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 291 Issued at 2200Z on 18 Oct 2002 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was at low levels. Region 162 (N25E71) produced the majority of the optically observed flare activity today, the largest was a C4/Sf event at 18/1927 UTC. The large cluster of spots seen in white-light appears to be all one region (based on current available magnetic data) although the regions proximity to the limb hinders any certainty at this time. Region 149 (N14W46) produced only minor B and C-class flares today. Magnetic analysis shows the return of the weak gamma magnetic structure that once again has become apparent. No other significant changes were seen in the region since yesterday. Region 158 (S08W02) produced a single optically correlated flare, a C1/Sf at 18/0703 UTC. This region retains a beta-gamma magnetic structure and underwent little change during the period. Newly numbered region 163 (S21W10) was assigned today. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. Region 162 may have the potential of producing isolated M-class flares. IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field activity was at predominantly quiet to unsettled levels with an isolated period of active conditions between 18/1500-1800 UTC due in part to the elevated solar wind speeds (550-650 km/s). The greater than 2 MeV electron flux at geosynchronous orbit reached moderate levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominately quiet to unsettled levels with a chance of isolated active conditions on days one and two due to the elevated solar wind speeds and a favorably positioned coronal hole. III. Event Probabilities 19 Oct-21 Oct Class M 40/40/40 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Oct 173 Predicted 19 Oct-21 Oct 175/175/180 90 Day Mean 18 Oct 182 V. Geomagnetic A Indices Observed Afr/Ap 17 Oct 008/011 Estimated Afr/Ap 18 Oct 010/012 Predicted Afr/Ap 19 Oct-21 Oct 008/012-010/012-006/008 VI. Geomagnetic Activity Probabilities 19 Oct-21 Oct A. Middle Latitudes Active 20/20/15 Minor storm 05/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 25/25/20 Minor storm 05/05/05 Major-severe storm 01/01/01