:Product: 0516RSGA.txt :Issued: 2015 May 16 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 136 Issued at 2200Z on 16 May 2015 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 15/2329Z from Region 2339 (N12W59). There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one and two (17 May, 18 May) and expected to be very low with a chance for a C-class flares on day three (19 May). IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 518 km/s at 16/0033Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 11005 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (17 May), quiet to active levels on day two (18 May) and unsettled levels on day three (19 May). III. Event probabilities 17 May-19 May Class M 15/15/05 Class X 05/05/01 Proton 05/05/01 PCAF green IV. Penticton 10.7 cm Flux Observed 16 May 131 Predicted 17 May-19 May 125/115/105 90 Day Mean 16 May 128 V. Geomagnetic A Indices Observed Afr/Ap 15 May 007/008 Estimated Afr/Ap 16 May 006/006 Predicted Afr/Ap 17 May-19 May 016/020-012/015-011/012 VI. Geomagnetic Activity Probabilities 17 May-19 May A. Middle Latitudes Active 30/30/25 Minor Storm 15/10/05 Major-severe storm 05/01/01 B. High Latitudes Active 10/15/15 Minor Storm 25/30/25 Major-severe storm 45/40/30