:Product: 20010128RSGA.txt :Issued: 2001 Jan 28 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 028 Issued at 2200Z on 28 Jan 2001 IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity increased to moderate levels. Region 9313 (S04W64) produced a long-duration M1/1n at 28/1603 UTC associated with a halo CME. Region 9313 showed significant decay prior to the flare. Occasional C-class flares occurred during the rest of the period. The remaining regions were either stable or declining. New Region 9328 (N06W58) was numbered. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. There will be a fair chance for an isolated M-class flare sometime during the period. IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: Geomagnetic field activity was at quiet to active levels. An isolated active period occurred during 28/1200 - 1500 UTC. A proton event at greater than 10 MeV began at 28/2025 UTC following the M1/1n flare from Region 9313. By the close of the period, the greater than 10 MeV flux reached 23.1 pfu and was gradually increasing. The greater than 2 MeV electron flux reached high levels late in the period. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to increase to unsettled to active levels during 30 - 31 January in response to today's halo CME. The greater than 10 MeV proton event is expected to end early on 29 January. The greater than 2 MeV electron flux may again reach high levels during the first half of the period. III. Event Probabilities 29 Jan-31 Jan Class M 40/40/35 Class X 05/05/05 Proton 05/05/05 PCAF yellow IV. Penticton 10.7 cm Flux Observed 28 Jan 168 Predicted 29 Jan-31 Jan 165/160/160 90 Day Mean 28 Jan 174 V. Geomagnetic A Indices Observed Afr/Ap 27 Jan 002/004 Estimated Afr/Ap 28 Jan 007/005 Predicted Afr/Ap 29 Jan-31 Jan 007/004-010/008-015/015 VI. Geomagnetic Activity Probabilities 29 Jan-31 Jan A. Middle Latitudes Active 20/20/30 Minor storm 10/10/15 Major-severe storm 05/05/05 B. High Latitudes Active 20/25/40 Minor storm 10/10/20 Major-severe storm 05/05/05