:Product: 1218RSGA.txt :Issued: 2016 Dec 18 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 353 Issued at 2200Z on 18 Dec 2016 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (19 Dec, 20 Dec, 21 Dec). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 467 km/s at 18/0245Z. Total IMF reached 11 nT at 17/2308Z. The maximum southward component of Bz reached -9 nT at 17/2311Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1565 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (19 Dec, 20 Dec) and unsettled to minor storm levels on day three (21 Dec). III. Event probabilities 19 Dec-21 Dec Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Dec 072 Predicted 19 Dec-21 Dec 073/073/073 90 Day Mean 18 Dec 082 V. Geomagnetic A Indices Observed Afr/Ap 17 Dec 003/003 Estimated Afr/Ap 18 Dec 010/010 Predicted Afr/Ap 19 Dec-21 Dec 011/015-012/015-017/025 VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec A. Middle Latitudes Active 30/30/40 Minor Storm 10/10/25 Major-severe storm 01/01/05 B. High Latitudes Active 15/15/10 Minor Storm 30/30/25 Major-severe storm 40/40/60