:Product: 0510RSGA.txt :Issued: 2012 May 10 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 131 Issued at 2200Z on 10 May 2012 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been at high levels for the past 24 hours with multiple M-class solar flares observed. Region 1476 (N12E08) was responsible for almost all of the activity with 3 M-class events observed, the largest being a M5/2b event at 10/0418Z. Associated with these events, were discrete frequency radio bursts, Tenflares, and even a Type IV radio sweep. Region 1476 has shown mixed growth and shear effects across the polarities as it continues to evolve. A weak Earth directed CME was observed in STEREO COR2 A and B imagery early in the period. Analysis and current models show this CME joining the current coronal hole high speed stream (CH HSS). Region 1477 (S22E47) was split into two regions today as SDO magnetogram data indicated the leader and follower sunspot groups were actually two magnetic bipoles. Leader group is Region 1477 and follower group is now Region 1478 (S24E55). IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels with a slight chance for X-class events for the next three days (11 - 13 May) as Region 1476 continues to grow and evolve. IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours with an isolated minor storm period observed at high latitudes. Solar wind measurements, as observed by the ACE spacecraft, showed a continued increase in solar wind speeds to around 620 km/s, a drop off in solar wind density, and the total IMF began to stabilize around 5 nT. These characteristics are indicative of a CH HSS. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels with a chance for active periods for the next three days (11 - 13 May). The increased activity is due to both the continued CH HSS effects and three weak, slow moving CMEs intertwined within. III. Event Probabilities 11 May-13 May Class M 75/75/75 Class X 20/20/20 Proton 10/10/10 PCAF Green IV. Penticton 10.7 cm Flux Observed 10 May 131 Predicted 11 May-13 May 130/130/130 90 Day Mean 10 May 113 V. Geomagnetic A Indices Observed Afr/Ap 09 May 019/025 Estimated Afr/Ap 10 May 010/010 Predicted Afr/Ap 11 May-13 May 012/012-010/012-006/010 VI. Geomagnetic Activity Probabilities 11 May-13 May A. Middle Latitudes Active 20/20/15 Minor storm 05/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 40/40/30 Minor storm 10/10/10 Major-severe storm 01/01/01