:Product: 20030317RSGA.txt :Issued: 2003 Mar 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 076 Issued at 2200Z on 17 Mar 2003 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was high. Region 314 (S16W39) produced an X1/1b flare at 17/1905 UTC. The flare was accompanied by a 520 sfu radio burst at 2695 MHz. This region also produced several C-class events over the past 24 hours. Sunspots continued to grow and the delta configuration in the trailer spots had intensified since yesterday. Other disk regions were relatively quiet. IB. Solar Activity Forecast: Solar activity is expected to be moderate. M-class activity is likely in Region 314, including the possibility of another major flare. IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field ranged from unsettled to major storm levels under the influence of a coronal hole high-speed stream. Solar wind speeds remained above 600 km/s and Bz fluctuated between +/- 10 nT. The greater than 2 MeV electron flux at geosynchronous orbit was high. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly active over the next 24 hours with the possibility of minor storm periods. Activity levels are expected to abate by the end of the three-day forecast period. III. Event Probabilities 18 Mar-20 Mar Class M 50/50/50 Class X 05/05/05 Proton 05/05/05 PCAF red IV. Penticton 10.7 cm Flux Observed 17 Mar 125 Predicted 18 Mar-20 Mar 130/130/125 90 Day Mean 17 Mar 138 V. Geomagnetic A Indices Observed Afr/Ap 16 Mar 012/023 Estimated Afr/Ap 17 Mar 025/040 Predicted Afr/Ap 18 Mar-20 Mar 020/020-015/015-012/015 VI. Geomagnetic Activity Probabilities 18 Mar-20 Mar A. Middle Latitudes Active 50/40/40 Minor storm 10/10/10 Major-severe storm 05/01/01 B. High Latitudes Active 60/50/50 Minor storm 20/15/15 Major-severe storm 10/05/05