:Product: 0515RSGA.txt :Issued: 2013 May 15 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 135 Issued at 2200Z on 15 May 2013 IA. Analysis of Solar Active Regions and Activity from 14/2100Z to 15/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a X1 event observed at 15/0148Z from Region 1748 (N11E51). There are currently 9 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be high on days one, two, and three (16 May, 17 May, 18 May). IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 457 km/s at 15/1605Z. Total IMF reached 11 nT at 15/1317Z. The maximum southward component of Bz reached -8 nT at 15/1124Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 23 pfu at 15/1850Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (16 May, 18 May) and quiet to active levels on day two (17 May). Protons are expected to cross threshold on days one, two, and three (16 May, 17 May, 18 May). III. Event probabilities 16 May-18 May Class M 80/80/80 Class X 60/60/60 Proton 99/90/90 PCAF yellow IV. Penticton 10.7 cm Flux Observed 15 May 146 Predicted 16 May-18 May 145/145/145 90 Day Mean 15 May 120 V. Geomagnetic A Indices Observed Afr/Ap 14 May 007/009 Estimated Afr/Ap 15 May 007/010 Predicted Afr/Ap 16 May-18 May 006/008-011/015-008/008 VI. Geomagnetic Activity Probabilities 16 May-18 May A. Middle Latitudes Active 15/30/15 Minor Storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/30/25 Major-severe storm 25/40/25