Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 360 Issued at 2200Z on 25 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: 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 (26 Dec, 27 Dec, 28 Dec).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 535 km/s at 25/0349Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1525 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (26 Dec) and quiet levels on days two and three (27 Dec, 28 Dec).

III. Event probabilities 26 Dec-28 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Dec 088
Predicted 26 Dec-28 Dec 088/088/088
90 Day Mean 25 Dec 083

V. Geomagnetic A Indices
Observed Afr/Ap 24 Dec 007/007
Estimated Afr/Ap 25 Dec 006/006
Predicted Afr/Ap 26 Dec-28 Dec 008/008-005/005-006/005

VI. Geomagnetic Activity Probabilities 26 Dec-28 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