Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 363 Issued at 2200Z on 28 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 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 (29 Dec, 30 Dec, 31 Dec).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 606 km/s at 28/0752Z. Total IMF reached 8 nT at 28/0219Z. The maximum southward component of Bz reached -6 nT at 28/0228Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 737 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (29 Dec) and quiet levels on days two and three (30 Dec, 31 Dec).

III. Event probabilities 29 Dec-31 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Dec 087
Predicted 29 Dec-31 Dec 087/087/087
90 Day Mean 28 Dec 084

V. Geomagnetic A Indices
Observed Afr/Ap 27 Dec 004/004
Estimated Afr/Ap 28 Dec 006/008
Predicted Afr/Ap 29 Dec-31 Dec 008/008-005/005-006/005

VI. Geomagnetic Activity Probabilities 29 Dec-31 Dec
A. Middle Latitudes
Active 20/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 25/10/10