:Product: 1020RSGA.txt :Issued: 2010 Oct 20 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 293 Issued at 2200Z on 20 Oct 2010 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was at low levels. Region 1112 (S20W84) produced the lone event of the period, a C1.5/Sf at 20/1150Z. The remaining regions were quiet and unchanged. IB. Solar Activity Forecast: Solar activity is expected to be predominately very low all three days of the forecast period (21 - 23 October). A chance for an isolated C-class event exists on day one (21 October) from departing Region 1112, decaying to a slight chance of C-class activity on days two and three (22 - 23 October). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet. Solar wind velocities remained steady during the period, varying between 420 - 460 km/s while the Bz component of the interplanetary magnetic field remained predominately north. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active periods on day one (21 October). A small, recurrent coronal hole high speed stream (CH HSS) is expected to rotate into a geoeffective position on 21 October. By day two (22 October), field conditions are expected to be mostly quiet. Late on day three (23 October), a large, recurrent CH HSS is expected to become geoeffective, resulting in quiet to active conditions. III. Event Probabilities 21 Oct-23 Oct Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 20 Oct 084 Predicted 21 Oct-23 Oct 084/083/082 90 Day Mean 20 Oct 081 V. Geomagnetic A Indices Observed Afr/Ap 19 Oct 007/005 Estimated Afr/Ap 20 Oct 004/005 Predicted Afr/Ap 21 Oct-23 Oct 008/008-005/005-008/010 VI. Geomagnetic Activity Probabilities 21 Oct-23 Oct A. Middle Latitudes Active 20/05/20 Minor storm 05/01/05 Major-severe storm 01/01/01 B. High Latitudes Active 25/10/25 Minor storm 10/01/10 Major-severe storm 01/01/01