:Product: 1217RSGA.txt :Issued: 2014 Dec 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 351 Issued at 2200Z on 17 Dec 2014 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M8 event observed at 17/0451Z from Region 2242 (S18W01). There are currently 9 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 Dec, 19 Dec, 20 Dec). 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 454 km/s at 17/0219Z. Total IMF reached 6 nT at 17/1503Z. The maximum southward component of Bz reached -5 nT at 17/0248Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 653 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 Dec) and quiet to active levels on days two and three (19 Dec, 20 Dec). Protons have a slight chance of crossing threshold on days one, two, and three (18 Dec, 19 Dec, 20 Dec). III. Event probabilities 18 Dec-20 Dec Class M 65/65/65 Class X 15/15/15 Proton 15/15/15 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Dec 192 Predicted 18 Dec-20 Dec 190/190/185 90 Day Mean 17 Dec 154 V. Geomagnetic A Indices Observed Afr/Ap 16 Dec 007/006 Estimated Afr/Ap 17 Dec 008/009 Predicted Afr/Ap 18 Dec-20 Dec 007/008-010/010-014/015 VI. Geomagnetic Activity Probabilities 18 Dec-20 Dec A. Middle Latitudes Active 15/30/30 Minor Storm 05/15/15 Major-severe storm 01/05/05 B. High Latitudes Active 15/15/15 Minor Storm 25/30/30 Major-severe storm 20/50/50