:Product: 1227RSGA.txt :Issued: 2011 Dec 27 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 361 Issued at 2200Z on 27 Dec 2011 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity has been at low levels for the past 24 hours. Regions 1386 (S18E22) and 1387 (S21W57) both have produced multiple C-class events, with the largest being a C8/1f at 27/0422Z from Region 1386. Associated with this event, was a non Earth directed CME. Both Regions continue to grow and evolve as they rotate across the disk. Region 1388 (S23E67) was numbered early in the period as it rotated onto the east limb. IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels for the next three days (28 - 30 December). IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels with isolated periods of minor storm levels on days one and two (28 - 29 December) with multiple CME arrivals expected. A decrease in activity is expected on day three (30 December) as CME effects wane. III. Event Probabilities 28 Dec-30 Dec Class M 70/70/70 Class X 01/01/01 Proton 10/10/10 PCAF Green IV. Penticton 10.7 cm Flux Observed 27 Dec 140 Predicted 28 Dec-30 Dec 140/140/140 90 Day Mean 27 Dec 144 V. Geomagnetic A Indices Observed Afr/Ap 26 Dec 002/000 Estimated Afr/Ap 27 Dec 000/000 Predicted Afr/Ap 28 Dec-30 Dec 012/018-014/022-011/010 VI. Geomagnetic Activity Probabilities 28 Dec-30 Dec A. Middle Latitudes Active 20/25/15 Minor storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/15/15 Minor storm 25/30/20 Major-severe storm 20/40/20