:Product: 1021RSGA.txt :Issued: 2010 Oct 21 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 294 Issued at 2200Z on 21 Oct 2010 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. Todays activity consisted of occasional, low-level B-class flares. Most of these were either from Region 1112 (S20, behind west limb) or Region 1117 (N23E48), although at least one event appeared to originate from a new group just behind the East limb (around N25). Regions 1113 (N16W31) and 1115 (S29W13) were quiet and stable. IB. Solar Activity Forecast: Solar activity is expected to be very low, although there is a slight chance for an isolated C-class event during the next three days (22-24 October). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be generally quiet for the first day (22 October) and about halfway through the second day (23 October). Sometime around mid-day on 23 October and continuing through the third day (24 October), an increase to unsettled levels with a chance for active periods is expected. There is also a chance for isolated storm periods at some locations during this interval. The increase is forecast because of expected effects from a high speed solar wind stream from a favorably positioned coronal hole. III. Event Probabilities 22 Oct-24 Oct Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 21 Oct 084 Predicted 22 Oct-24 Oct 082/082/082 90 Day Mean 21 Oct 081 V. Geomagnetic A Indices Observed Afr/Ap 20 Oct 003/004 Estimated Afr/Ap 21 Oct 003/005 Predicted Afr/Ap 22 Oct-24 Oct 005/005-010/010-015/015 VI. Geomagnetic Activity Probabilities 22 Oct-24 Oct A. Middle Latitudes Active 05/30/40 Minor storm 01/15/20 Major-severe storm 01/05/05 B. High Latitudes Active 05/35/45 Minor storm 01/20/25 Major-severe storm 01/10/15