:Product: 0527RSGA.txt :Issued: 2013 May 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 Solar Geophysical Activity Report and Forecast SDF Number 147 Issued at 2200Z on 27 May 2013 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. The largest solar event of the period was a C1 event observed at 26/2147Z from Region 1756 (S20W26). There are currently 5 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (28 May, 29 May, 30 May). IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 805 km/s at 27/1737Z. Total IMF reached 6 nT at 27/1116Z. The maximum southward component of Bz reached -6 nT at 27/1117Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 58767 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (28 May) and quiet levels on days two and three (29 May, 30 May). III. Event probabilities 28 May-30 May Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 27 May 110 Predicted 28 May-30 May 110/110/110 90 Day Mean 27 May 123 V. Geomagnetic A Indices Observed Afr/Ap 26 May 019/019 Estimated Afr/Ap 27 May 012/014 Predicted Afr/Ap 28 May-30 May 007/008-004/005-005/005 VI. Geomagnetic Activity Probabilities 28 May-30 May A. Middle Latitudes Active 10/10/10 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/20/20 Major-severe storm 20/10/10