:Product: 0121RSGA.txt :Issued: 2012 Jan 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 021 Issued at 2200Z on 21 Jan 2012 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was low. Isolated low-level C-class flares were observed. Plage Region 1396 (N25W86) produced a C1 x-ray flare at 20/2112Z associated with a Type II radio sweep (estimated shock velocity 945 km/s) and a non-Earth-directed coronal mass ejection (CME). Region 1402 (N29W11) produced a long-duration C1 at 20/2333Z associated with a weak Type IV radio sweep. Region 1402 showed gradual trailer spot decay during the period and was classified as a Cko group with a beta magnetic configuration. Region 1401 (N17W14) also showed gradual trailer spot decay and was classified as an Ehi group with a beta magnetic classification. New Regions 1408 (N08E69) and 1409 (N16E50) were numbered. Both were small and simply-structured. IB. Solar Activity Forecast: Solar activity is expected to be low through the period (22 - 24 January) with a chance for an isolated M-class flare. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was at mostly quiet levels with brief active to minor storm levels at high latitudes. A weak interplanetary shock was observed at the ACE spacecraft at around 21/0400Z. This was followed by a weak geomagnetic sudden impulse at 21/0502Z (7 nT, Boulder USGS magnetometer). IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly quiet levels until late on day 1 (22 January). Activity is forecast to increase to unsettled to active levels at around 22/1800Z and continue into day 2 (23 January) due to the expected arrival of the halo-CME observed on 19 January. There will also be a chance for minor storm levels during the CME passage. Field activity is expected to decrease to quiet to unsettled levels on day 3 (24 January) as CME effects subside. III. Event Probabilities 22 Jan-24 Jan Class M 35/35/35 Class X 01/01/01 Proton 10/10/10 PCAF Green IV. Penticton 10.7 cm Flux Observed 21 Jan 142 Predicted 22 Jan-24 Jan 145/145/145 90 Day Mean 21 Jan 143 V. Geomagnetic A Indices Observed Afr/Ap 20 Jan 003/004 Estimated Afr/Ap 21 Jan 005/005 Predicted Afr/Ap 22 Jan-24 Jan 009/010-020/025-007/008 VI. Geomagnetic Activity Probabilities 22 Jan-24 Jan A. Middle Latitudes Active 25/40/10 Minor storm 10/20/01 Major-severe storm 01/05/01 B. High Latitudes Active 30/50/20 Minor storm 20/25/10 Major-severe storm 05/10/01