:Product: 20020913RSGA.txt :Issued: 2002 Sep 13 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 256 Issued at 2200Z on 13 Sep 2002 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was at low levels. Region 105 (S08E03) produced a C1/Sf flare at 12/2337 UTC, which was the largest during the period. Even so, it remains the largest and most magnetically complex region on the visible disk. It's dominant trailing spot retains a beta-gamma-delta magnetic configuration. Region 103 (N16W58) showed some decay in penumbral coverage and exhibited no significant activity today. Region 107 (N11E03) underwent little change and was quiescent during the period. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. M-class activity remains possible from regions 105 and 107. IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field ranged from quiet to minor storm levels. An isolated period of minor storm conditions existed at mid-latitudes from 13/0600 to 0900 UTC. Coronal hole high speed stream effects continued to be the main source of the elevated activity. The greater than 2 MeV electron flux at geosynchronous orbit exceeded event threshold at 13/1620 UTC, reached a maximum value of 1070 pfu at 13/1805 UTC, and fell below threshold at value at 13/1810 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels through the first day of the period as the coronal hole high speed stream effects subside. A return to quiet to unsettled conditions are expected for the remainder of the forecast period. Greater than 2 MeV flux at geosynchronous orbit may be elevated into day one of the period. III. Event Probabilities 14 Sep-16 Sep Class M 50/50/50 Class X 05/05/05 Proton 05/05/05 PCAF yellow IV. Penticton 10.7 cm Flux Observed 13 Sep 206 Predicted 14 Sep-16 Sep 205/200/190 90 Day Mean 13 Sep 175 V. Geomagnetic A Indices Observed Afr/Ap 12 Sep 009/017 Estimated Afr/Ap 13 Sep 012/014 Predicted Afr/Ap 14 Sep-16 Sep 012/012-008/008-008/008 VI. Geomagnetic Activity Probabilities 14 Sep-16 Sep A. Middle Latitudes Active 25/15/15 Minor storm 05/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 30/20/20 Minor storm 10/05/05 Major-severe storm 01/01/04