Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 358 Issued at 2200Z on 23 Dec 2020

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: 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 (24 Dec, 25 Dec, 26 Dec).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 644 km/s at 23/1007Z. Total IMF reached 7 nT at 23/0346Z. The maximum southward component of Bz reached -6 nT at 23/0223Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 550 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (24 Dec), quiet to active levels on day two (25 Dec) and quiet to unsettled levels on day three (26 Dec).

III. Event probabilities 24 Dec-26 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Dec 086
Predicted 24 Dec-26 Dec 086/088/088
90 Day Mean 23 Dec 083

V. Geomagnetic A Indices
Observed Afr/Ap 22 Dec 011/010
Estimated Afr/Ap 23 Dec 015/016
Predicted Afr/Ap 24 Dec-26 Dec 018/022-011/015-008/008

VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec
A. Middle Latitudes
Active 40/30/20
Minor Storm 30/15/05
Major-severe storm 10/01/01
B. High Latitudes
Active 05/15/15
Minor Storm 25/30/25
Major-severe storm 65/45/25