:Product: 0522RSGA.txt :Issued: 2013 May 22 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 142 Issued at 2200Z on 22 May 2013 IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M5 event observed at 22/1332Z from Region 1745 (N13W80). There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (23 May, 24 May, 25 May). IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: 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 500 km/s at 22/0442Z. Total IMF reached 6 nT at 22/2005Z. The maximum southward component of Bz reached -5 nT at 21/2357Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 279 pfu at 22/2035Z. Protons greater than 100 MeV at geosynchronous orbit reached a peak level of 3 pfu at 22/1830Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 722 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (23 May), quiet to unsettled levels on day two (24 May) and quiet to active levels on day three (25 May). Protons are expected to cross threshold on days one and two (23 May, 24 May) and are likely to cross threshold on day three (25 May). III. Event probabilities 23 May-25 May Class M 50/50/50 Class X 20/20/20 Proton 99/99/70 PCAF RED IV. Penticton 10.7 cm Flux Observed 22 May 133 Predicted 23 May-25 May 125/125/130 90 Day Mean 22 May 122 V. Geomagnetic A Indices Observed Afr/Ap 21 May 008/008 Estimated Afr/Ap 22 May 009/012 Predicted Afr/Ap 23 May-25 May 012/012-007/015-012/008 VI. Geomagnetic Activity Probabilities 23 May-25 May A. Middle Latitudes Active 30/15/30 Minor Storm 10/05/15 Major-severe storm 01/01/05 B. High Latitudes Active 15/15/15 Minor Storm 30/25/25 Major-severe storm 40/25/45