Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 9 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 252 Issued at 2200Z on 09 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 09/0831Z from Region 2866 (S18W06). There are currently 6 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 (10 Sep, 11 Sep, 12 Sep).

IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 436 km/s at 09/0808Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 240 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (10 Sep) and quiet to unsettled levels on days two and three (11 Sep, 12 Sep).

III. Event probabilities 10 Sep-12 Sep
Class M 20/20/20
Class X 05/05/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 09 Sep 100
Predicted 10 Sep-12 Sep 100/100/098
90 Day Mean 09 Sep 081

V. Geomagnetic A Indices
Observed Afr/Ap 08 Sep 014/014
Estimated Afr/Ap 09 Sep 006/006
Predicted Afr/Ap 10 Sep-12 Sep 006/005-007/008-008/008

VI. Geomagnetic Activity Probabilities 10 Sep-12 Sep
A. Middle Latitudes
Active 10/15/15
Minor Storm 01/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/25
Major-severe storm 20/25/25