:Product: 20010617RSGA.txt :Issued: 2001 Jun 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 168 Issued at 2200Z on 17 Jun 2001 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been low. Today's largest event was a C3 at 2242 UTC which was not seen optically. Region 9503 (N14E20) is currently the largest group on the disk, and shows continued growth, enhanced plage and occasional brightenings. Region 9501 (S13W11) has also shown growth during the past 24 hours. Region 9502 (S25E05) continues to have an east-west inversion line, but appeared to be a bit cooler today than previously. Region 9506 (N17E48) has rotated into view as a beta-gamma group, but was relatively calm and stable. Two filaments disappeared during the past 24 hours: a 14 degree filament near S27W11, and a 28 degree filament near N30E55. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate for the next three days. There is a slight chance, however, for an isolated major flare event, particularly from 9503 and 9506. IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field ranged from quiet to active levels. Quiet conditions prevailed during the first 15 hours of the period, but activity increased to unsettled to slightly active between 1200-2100 UTC. Solar wind signatures showed some kind of transient type flow from 0300-1600 UTC which was accompanied be moderately negative interplanetary Bz. IIB. Geophysical Activity Forecast: The geomagnetic field for the next 24 hours is expected to be mostly unsettled, but with a chance for isolated active periods. Unsettled levels should prevail on the second day, and activity should drop to quiet to unsettled levels by the third day. III. Event Probabilities 18 Jun-20 Jun Class M 60/60/60 Class X 10/10/10 Proton 05/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Jun 205 Predicted 18 Jun-20 Jun 200/200/195 90 Day Mean 17 Jun 172 V. Geomagnetic A Indices Observed Afr/Ap 16 Jun 004/007 Estimated Afr/Ap 17 Jun 010/012 Predicted Afr/Ap 18 Jun-20 Jun 015/015-010/010-005/010 VI. Geomagnetic Activity Probabilities 18 Jun-20 Jun A. Middle Latitudes Active 35/25/20 Minor storm 15/15/10 Major-severe storm 10/05/05 B. High Latitudes Active 35/30/25 Minor storm 25/20/15 Major-severe storm 15/10/05