:Product: 20050529RSGA.txt :Issued: 2005 May 29 2210 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 149 Issued at 2200Z on 29 May 2005 IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity was low. A C1.7 flare occurred at 28/2217 UTC which was probably produced by Region 769 (S08E59); however, the full extent of this region is hard to determine due to its proximity to the east limb. Region 767 (S09W31) has decayed to 200 millionths in area. New Region 770 (N12E00) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be very low to low with a slight chance for an M-class event from Region 767. IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field was quiet to active. Heightened activity was due to the arrival of the full halo CME observed on 26 May combined with a coronal hole high speed stream. A shock was observed at ACE at approximately 29/0900 UTC and a sudden impulse of 30 nT was observed at 29/0953 UTC. Solar wind speed at ACE increased to 450 km/s during the initial shock and is now between 500 km/s and 550 km/s. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet to unsettled with isolated active conditions possible on 30 May. Quiet to unsettled conditions are expected on 31 May and 01 June. III. Event Probabilities 30 May-01 Jun Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 29 May 093 Predicted 30 May-01 Jun 100/100/100 90 Day Mean 29 May 092 V. Geomagnetic A Indices Observed Afr/Ap 28 May 009/013 Estimated Afr/Ap 29 May 012/015 Predicted Afr/Ap 30 May-01 Jun 008/010-008/008-005/008 VI. Geomagnetic Activity Probabilities 30 May-01 Jun A. Middle Latitudes Active 20/20/15 Minor storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 25/20/20 Minor storm 15/10/10 Major-severe storm 01/01/01