Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 29 December 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 363 Issued at 2200Z on 29 Dec 2021

IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 29/0428Z from Region 2916 (S17W22). There are currently 5 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 (30 Dec, 31 Dec, 01 Jan).

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 468 km/s at 28/2100Z. Total IMF reached 11 nT at 29/2049Z. The maximum southward component of Bz reached -4 nT at 29/1302Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 935 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one, two, and three (30 Dec, 31 Dec, 01 Jan).

III. Event probabilities 30 Dec-01 Jan
Class M 15/15/15
Class X 05/05/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 29 Dec 111
Predicted 30 Dec-01 Jan 110/108/105
90 Day Mean 29 Dec 093

V. Geomagnetic A Indices
Observed Afr/Ap 28 Dec 006/007
Estimated Afr/Ap 29 Dec 006/007
Predicted Afr/Ap 30 Dec-01 Jan 008/010-007/008-005/006

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