:Product: 1126RSGA.txt :Issued: 2012 Nov 26 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 Solar Geophysical Activity Report and Forecast SDF Number 331 Issued at 2200Z on 26 Nov 2012 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 26/1526Z from Region 1620 (S13W28). The region grew significantly overnight and is now considered an Esi-type region with a beta-gamma magnetic configuration. Region 1618 (N08W69) continued to decay, however, it maintained a weak delta in its trailing spot. There are currently 4 numbered sunspot regions on the disk. A filament eruption was observed south of Region 1620 in SDO/AIA 304 imagery beginning at 26/0343Z. A model run is in progress to determine geoeffectiveness. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels on days one, two, and three (27 Nov, 28 Nov, 29 Nov). IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. A shock passage was observed at 26/0437Z indicating the possible early arrival of the 23 November CME followed by an 8 nT Sudden Impulse (SI) observed at the Boulder magnetometer at 26/0514Z. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 558 km/s at 26/0709Z. Total IMF reached 12.8 nT at 26/0749Z. The maximum southward component of Bz reached -7.8 nT at 26/0729Z although it has remained positive since about 26/1000Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels with a chance for isolated active periods on day one (27 Nov) as CME effects begin to wane. Mostly quiet conditions are expected on days two and three (28 Nov, 29 Nov). III. Event probabilities 27 Nov-29 Nov Class M 35/35/35 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 26 Nov 122 Predicted 27 Nov-29 Nov 120/120/115 90 Day Mean 26 Nov 123 V. Geomagnetic A Indices Observed Afr/Ap 25 Nov 004/004 Estimated Afr/Ap 26 Nov 005/005 Predicted Afr/Ap 27 Nov-29 Nov 011/012-006/005-006/005 VI. Geomagnetic Activity Probabilities 27 Nov-29 Nov A. Middle Latitudes Active 25/10/05 Minor Storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/15/10 Major-severe storm 35/15/05