Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 13 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 256 Issued at 2200Z on 13 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one and two (14 Sep, 15 Sep) and expected to be very low with a slight chance for a C-class flare on day three (16 Sep).

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 520 km/s at 13/1612Z. Total IMF reached 9 nT at 13/0247Z. The maximum southward component of Bz reached -7 nT at 13/0543Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 392 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (14 Sep) and quiet levels on days two and three (15 Sep, 16 Sep).

III. Event probabilities 14 Sep-16 Sep
Class M 05/05/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 13 Sep 083
Predicted 14 Sep-16 Sep 082/081/080
90 Day Mean 13 Sep 082

V. Geomagnetic A Indices
Observed Afr/Ap 12 Sep 006/005
Estimated Afr/Ap 13 Sep 007/008
Predicted Afr/Ap 14 Sep-16 Sep 007/008-006/005-006/005

VI. Geomagnetic Activity Probabilities 14 Sep-16 Sep
A. Middle Latitudes
Active 15/15/10
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor Storm 30/25/20
Major-severe storm 25/20/20