Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 December 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 356 Issued at 2200Z on 21 Dec 2016

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 (22 Dec, 23 Dec, 24 Dec).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 674 km/s at 21/1251Z. Total IMF reached 15 nT at 21/1626Z. The maximum southward component of Bz reached -11 nT at 21/0839Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 506 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to minor storm levels on day one (22 Dec) and quiet to active levels on days two and three (23 Dec, 24 Dec).

III. Event probabilities 22 Dec-24 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Dec 075
Predicted 22 Dec-24 Dec 075/080/085
90 Day Mean 21 Dec 081

V. Geomagnetic A Indices
Observed Afr/Ap 20 Dec 004/004
Estimated Afr/Ap 21 Dec 020/028
Predicted Afr/Ap 22 Dec-24 Dec 020/030-011/012-010/012

VI. Geomagnetic Activity Probabilities 22 Dec-24 Dec
A. Middle Latitudes
Active 40/25/25
Minor Storm 25/10/10
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/25/25
Major-severe storm 60/35/35