Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 8 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 251 Issued at 2200Z on 08 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 07/2100Z to 08/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C8 event observed at 08/1730Z from Region 2866 (S18E07). There are currently 5 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one, two, and three (09 Sep, 10 Sep, 11 Sep).

IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z: The geomagnetic speed reached a peak of 440 km/s at 08/1028Z. Total IMF reached 12 nT at 08/0850Z. The maximum southward component of Bz reached -9 nT at 08/0930Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 277 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (09 Sep) and quiet levels on days two and three (10 Sep, 11 Sep).

III. Event probabilities 09 Sep-11 Sep
Class M 20/20/20
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 08 Sep 100
Predicted 09 Sep-11 Sep 100/100/100
90 Day Mean 08 Sep 081

V. Geomagnetic A Indices
Observed Afr/Ap 07 Sep 010/009
Estimated Afr/Ap 08 Sep 014/016
Predicted Afr/Ap 09 Sep-11 Sep 007/008-006/005-005/005

VI. Geomagnetic Activity Probabilities 09 Sep-11 Sep
A. Middle Latitudes
Active 20/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 25/20/20