:Product: 20010131RSGA.txt :Issued: 2001 Jan 31 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 031 Issued at 2200Z on 31 Jan 2001 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been low. The greatest activity of note was an optically uncorrelated C2 flare at 30/2237 UTC. A bright surge on the disk near spotless region 9216 (S15W84) was also observed at 31/1536 UTC, but with only minor accompanying x-ray enhancement. Region 9330 (N26E57) has rotated into full view as the largest region on the disk (230 millionths coverage in white light, in an Eao-Beta configuration), but produced no activity of note during the period. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low, with only isolated chances for moderate activity during the next three days. IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: Geomagnetic field activity ranged from quiet to minor storm levels. Shock passage associated with the CME of January 28 was observed at the ACE satellite at 31/0742 UTC, with a subsequent sudden impulse (17 nT) observed at Boulder at 31/0803 UTC. Unsettled to active conditions have predominated since, with an isolated period of minor storming recorded for higher latitudes during 31/0900-1200 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels through February 1, reducing to quiet to unsettled levels for February 2-3. III. Event Probabilities 01 Feb-03 Feb Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Jan 153 Predicted 01 Feb-03 Feb 155/160/165 90 Day Mean 31 Jan 172 V. Geomagnetic A Indices Observed Afr/Ap 30 Jan 003/004 Estimated Afr/Ap 31 Jan 013/018 Predicted Afr/Ap 01 Feb-03 Feb 008/008-005/005-005/005 VI. Geomagnetic Activity Probabilities 01 Feb-03 Feb A. Middle Latitudes Active 25/25/20 Minor storm 10/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 30/25/25 Minor storm 15/10/05 Major-severe storm 05/05/01