Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 361 Issued at 2200Z on 26 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: 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 (27 Dec, 28 Dec, 29 Dec).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 460 km/s at 25/2132Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1006 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expectedto be at quiet levels on days one and two (27 Dec, 28 Dec) and quiet to unsettled levels on day three (29 Dec).

III. Event probabilities 27 Dec-29 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Dec 088
Predicted 27 Dec-29 Dec 088/088/088
90 Day Mean 26 Dec 083

V. Geomagnetic A Indices
Observed Afr/Ap 25 Dec 004/004
Estimated Afr/Ap 26 Dec 004/004
Predicted Afr/Ap 27 Dec-29 Dec 005/005-006/005-008/008

VI. Geomagnetic Activity Probabilities 27 Dec-29 Dec
A. Middle Latitudes
Active 10/10/20
Minor Storm 01/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/25
Major-severe storm 10/10/25