Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 359 Issued at 2200Z on 24 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: 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 (25 Dec, 26 Dec, 27 Dec).

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 590 km/s at 24/1237Z. Total IMF reached 5 nT at 24/0506Z. The maximum southward component of Bz reached -4 nT at 24/1039Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1539 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (25 Dec), quiet to unsettled levels on day two (26 Dec) and quiet levels on day three (27 Dec).

III. Event probabilities 25 Dec-27 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 24 Dec 087
Predicted 25 Dec-27 Dec 088/088/088
90 Day Mean 24 Dec 083

V. Geomagnetic A Indices
Observed Afr/Ap 23 Dec 011/011
Estimated Afr/Ap 24 Dec 011/016
Predicted Afr/Ap 25 Dec-27 Dec 011/015-008/008-005/005

VI. Geomagnetic Activity Probabilities 25 Dec-27 Dec
A. Middle Latitudes
Active 30/20/10
Minor Storm 15/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/25/20
Major-severe storm 45/25/10