Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 14 December 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 348 Issued at 2200Z on 14 Dec 2021

IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 14/0826Z from Region 2907 (S21E49). There are currently 3 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (15 Dec, 16 Dec, 17 Dec).

IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 344 km/s at 14/2025Z. Total IMF reached 6 nT at 14/1930Z. The maximum southward component of Bz reached -6 nT at 14/0049Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 168 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (15 Dec) and quiet to unsettled levels on days two and three (16 Dec, 17 Dec).

III. Event probabilities 15 Dec-17 Dec
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 14 Dec 089
Predicted 15 Dec-17 Dec 090/092/092
90 Day Mean 14 Dec 086

V. Geomagnetic A Indices
Observed Afr/Ap 13 Dec 006/004
Estimated Afr/Ap 14 Dec 006/007
Predicted Afr/Ap 15 Dec-17 Dec 009/012-008/008-008/008

VI. Geomagnetic Activity Probabilities 15 Dec-17 Dec
A. Middle Latitudes
Active 30/25/15
Minor Storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/25
Major-severe storm 40/30/25