:Product: 0422RSGA.txt :Issued: 2006 Apr 22 2203 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 112 Issued at 2200Z on 22 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity was low. A C2 x-ray flare which reached maximum at 1639UTC was the largest event of the day. B-class flares were more numerous and all activity was seen to be centered on active regions just rotating onto the disk in the southern hemisphere. The sole spot group, Region 874 (S02W39), was quiet as it continued to decay. IB. Solar Activity Forecast: Solar activity is expected to be very low to low. Expect isolated C-class flares during the next three days. IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field was moderately disturbed early in the period, as conditions ranged from active to brief major storming at high latitudes. This activity was due to strong Alfven waves in the solar wind that caused periods of southward IMF to reach -15 nT at times. The solar wind returned to more normal conditions during the last 12 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled during the interval. Brief active conditions may occur in the near term as the solar wind speed, though decreasing, is still above 500 km/s. III. Event Probabilities 23 Apr-25 Apr Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 22 Apr 082 Predicted 23 Apr-25 Apr 085/085/085 90 Day Mean 22 Apr 078 V. Geomagnetic A Indices Observed Afr/Ap 21 Apr 006/008 Estimated Afr/Ap 22 Apr 015/020 Predicted Afr/Ap 23 Apr-25 Apr 010/010-005/008-005/008 VI. Geomagnetic Activity Probabilities 23 Apr-25 Apr A. Middle Latitudes Active 40/20/20 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 50/30/30 Minor storm 10/10/10 Major-severe storm 01/01/01