Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 255 Issued at 2200Z on 12 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 3 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 and two (13 Sep, 14 Sep) and expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day three (15 Sep).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 405 km/s at 12/2059Z. Total IMF reached 10 nT at 11/2103Z. The maximum southward component of Bz reached -7 nT at 12/0834Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 158 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (13 Sep, 14 Sep, 15 Sep).

III. Event probabilities 13 Sep-15 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 Sep 088
Predicted 13 Sep-15 Sep 086/082/082
90 Day Mean 12 Sep 082

V. Geomagnetic A Indices
Observed Afr/Ap 11 Sep 008/007
Estimated Afr/Ap 12 Sep 005/006
Predicted Afr/Ap 13 Sep-15 Sep 006/005-006/005-006/005

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