:Product: 0417RSGA.txt :Issued: 2014 Apr 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 107 Issued at 2200Z on 17 Apr 2014 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 C3 event observed at 17/1154Z. There are currently 12 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on days one, two, and three (18 Apr, 19 Apr, 20 Apr). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: 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 448 km/s at 17/1854Z. Total IMF reached 10 nT at 17/0528Z. The maximum southward component of Bz reached -8 nT at 17/1322Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 279 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 Apr), quiet to active levels on day two (19 Apr) and quiet to minor storm levels on day three (20 Apr). Protons have a slight chance of crossing threshold on days one, two, and three (18 Apr, 19 Apr, 20 Apr). III. Event probabilities 18 Apr-20 Apr Class M 60/60/60 Class X 10/10/10 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Apr 179 Predicted 18 Apr-20 Apr 180/180/180 90 Day Mean 17 Apr 155 V. Geomagnetic A Indices Observed Afr/Ap 16 Apr 005/004 Estimated Afr/Ap 17 Apr 007/008 Predicted Afr/Ap 18 Apr-20 Apr 008/008-009/012-015/020 VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr A. Middle Latitudes Active 20/40/40 Minor Storm 05/15/25 Major-severe storm 01/01/05 B. High Latitudes Active 15/10/10 Minor Storm 25/25/25 Major-severe storm 25/55/60