:Product: 0317RSGA.txt :Issued: 2013 Mar 17 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 76 Issued at 2200Z on 17 Mar 2013 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: 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 17/1253Z from Region 1698 (S19W72). There are currently 8 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 (18 Mar, 19 Mar) and expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day three (20 Mar). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 767 km/s at 17/1007Z. Total IMF reached 22 nT at 17/0744Z. The maximum southward component of Bz reached -20 nT at 17/0752Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 16 pfu at 17/0700Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 149 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (18 Mar), quiet to unsettled levels on day two (19 Mar) and quiet levels on day three (20 Mar). III. Event probabilities 18 Mar-20 Mar Class M 20/20/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Mar 126 Predicted 18 Mar-20 Mar 120/115/110 90 Day Mean 17 Mar 116 V. Geomagnetic A Indices Observed Afr/Ap 16 Mar 008/010 Estimated Afr/Ap 17 Mar 029/046 Predicted Afr/Ap 18 Mar-20 Mar 018/025-008/008-006/005 VI. Geomagnetic Activity Probabilities 18 Mar-20 Mar A. Middle Latitudes Active 35/15/05 Minor Storm 20/05/01 Major-severe storm 05/01/01 B. High Latitudes Active 10/15/15 Minor Storm 30/20/10 Major-severe storm 50/20/05