Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 December 2021
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 358 Issued at 2200Z on 24 Dec 2021
IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C7 event observed at 24/0342Z from Region 2917 (S27E05). There are currently 8 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on day one (25 Dec) and expected to be low with a slight chance for an M-class flare on day two (26 Dec) and expected to be very low with a chance for a C-class flares on day three (27 Dec).
IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 525 km/s at 24/0131Z. Total IMF reached 5 nT at 24/1847Z. The maximum southward component of Bz reached -4 nT at 24/1928Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2017 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (25 Dec, 26 Dec) and quiet to unsettled levels on day three (27 Dec). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (25 Dec).
III. Event probabilities 25 Dec-27 Dec
Class M 25/10/05
Class X 10/01/01
Proton 10/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 24 Dec 126
Predicted 25 Dec-27 Dec 125/120/115
90 Day Mean 24 Dec 091
V. Geomagnetic A Indices
Observed Afr/Ap 23 Dec 002/002
Estimated Afr/Ap 24 Dec 007/011
Predicted Afr/Ap 25 Dec-27 Dec 011/012-014/016-008/008
VI. Geomagnetic Activity Probabilities 25 Dec-27 Dec
A. Middle Latitudes
Active 30/30/25
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/30
Major-severe storm 40/40/30
