Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 10 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 253 Issued at 2200Z on 10 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been at very low levels for the past 24 hours. 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 (11 Sep, 12 Sep, 13 Sep).

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 392 km/s at 10/0730Z. Total IMF reached 12 nT at 10/1702Z. The maximum southward component of Bz reached -5 nT at 10/1945Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 306 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (11 Sep), quiet to unsettled levels on day two (12 Sep) and quiet levels on day three (13 Sep).

III. Event probabilities 11 Sep-13 Sep
Class M 20/20/20
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 10 Sep 096
Predicted 11 Sep-13 Sep 094/092/092
90 Day Mean 10 Sep 081

V. Geomagnetic A Indices
Observed Afr/Ap 09 Sep 007/004
Estimated Afr/Ap 10 Sep 007/008
Predicted Afr/Ap 11 Sep-13 Sep 014/014-008/008-006/005

VI. Geomagnetic Activity Probabilities 11 Sep-13 Sep
A. Middle Latitudes
Active 30/15/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/25/20
Major-severe storm 40/25/20