Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 362 Issued at 2200Z on 27 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: 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 (28Dec, 29 Dec, 30 Dec).

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 546 km/s at 27/1429Z. Total IMF reached 7 nT at 27/1537Z. The maximum southward component of Bz reached -5 nT at 27/0330Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1659 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and three (28 Dec, 30 Dec) and quiet to unsettled levels on day two (29 Dec).

III. Event probabilities 28 Dec-30 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 27 Dec 088
Predicted 28 Dec-30 Dec 088/088/088
90 Day Mean 27 Dec 084

V. Geomagnetic A Indices
Observed Afr/Ap 26 Dec 003/003
Estimated Afr/Ap 27 Dec 005/005
Predicted Afr/Ap 28 Dec-30 Dec 006/005-008/008-005/005

VI. Geomagnetic Activity Probabilities 28 Dec-30 Dec
A. Middle Latitudes
Active 10/20/10
Minor Storm 01/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/20
Major-severe storm 10/25/10