:Product: 0524RSGA.txt :Issued: 2013 May 24 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 144 Issued at 2200Z on 24 May 2013 IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: 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 24/0124Z. There are currently 5 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (25 May, 26 May, 27 May). IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 621 km/s at 24/2058Z. Total IMF reached 15 nT at 24/1739Z. The maximum southward component of Bz reached -14 nT at 24/1738Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 368 pfu at 23/2105Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2063 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (25 May) and quiet to unsettled levels on days two and three (26 May, 27 May). Protons are likely to continue above threshold levels on day one (25 May), have a chance of remaining above threshold on day two (26 May) and have a slight chance of remaining above threshold on day three (27 May). III. Event probabilities 25 May-27 May Class M 25/25/25 Class X 01/01/01 Proton 60/30/10 PCAF yellow IV. Penticton 10.7 cm Flux Observed 24 May 127 Predicted 25 May-27 May 130/125/125 90 Day Mean 24 May 122 V. Geomagnetic A Indices Observed Afr/Ap 23 May 008/008 Estimated Afr/Ap 24 May 014/019 Predicted Afr/Ap 25 May-27 May 014/022-008/012-007/008 VI. Geomagnetic Activity Probabilities 25 May-27 May A. Middle Latitudes Active 35/20/10 Minor Storm 20/05/01 Major-severe storm 05/01/01 B. High Latitudes Active 10/15/15 Minor Storm 30/25/20 Major-severe storm 55/25/20