:Product: 0527RSGA.txt :Issued: 2011 May 28 0225 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 :::::::::: CORRECTED COPY :::::::::: SDF Number 147 Issued at 2200Z on 27 May 2011 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity was low. New Region 1226 (S18E74) produced a B-class event and four C-class events since being numbered today. The largest was a C5 observed at 27/1643Z. This region began with a B1 event at 26/1654Z as it approached the southeast limb yesterday. It is currently an H-type group, however, the region is still rotating onto the disk and more white light area are evident in the SDO/HMI imagery just visible on the limb. Region 1223 (S16W00) produced the only other event during the period, a B4 at 27/0953Z. This region is a Dso group with a beta magnetic classification and grew slightly in sunspot count. Two more regions were numbered today as Regions 1224 (N21W15) and 1225 (N18E55). Region 1224 is a Dso group with a beta magnetic classification and 1225 is another H-type group. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for C-class events, and a slight chance for an M-class event, as regions on the disk continue to evolve. IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field was quiet to unsettled. Observations from the ACE spacecraft suggest the earth is under the continued influence of the co-rotating interaction region in advance of the recurrent coronal hole high speed stream. Solar winds have slowly increased from around 390 to 500 km/s. The IMF Bt averaged around 8 nT with the Bz mostly southward (-8 nT) through the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominately unsettled with occasional active periods, including isolated minor storm conditions at high-latitudes for day one (28 May). This is expected due to effects from the recurrent coronal hole high speed stream (CH HSS). In addition there are possible effects from the disappearing filament observed on 25 May. Quiet to unsettled conditions, with isolated active levels, are expected for days two and three (29-30 May) with continued CH HSS effects. III. Event Probabilities 28 May-30 May Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 27 May 090 Predicted 28 May-30 May 090/095/095 90 Day Mean 27 May 108 V. Geomagnetic A Indices Observed Afr/Ap 26 May 004/007 Estimated Afr/Ap 27 May 010/012 Predicted Afr/Ap 28 May-30 May 015/018-010/012-008/008 VI. Geomagnetic Activity Probabilities 28 May-30 May A. Middle Latitudes Active 25/20/15 Minor storm 10/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 35/30/20 Minor storm 15/10/10 Major-severe storm 05/05/05