Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 1 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 274 Issued at 2200Z on 01 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 01/2100Z: 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 and a slight chance for an M-class flare on days one, two, and three (02 Oct, 03 Oct, 04 Oct).

IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 569 km/s at 01/1838Z. Total IMF reached 12 nT at 01/2043Z. The maximum southward component of Bz reached -8 nT at 01/0711Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 148 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (02 Oct), quiet to unsettled levels on day two (03 Oct) and quiet levels on day three (04 Oct).

III. Event probabilities 02 Oct-04 Oct
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 01 Oct 091
Predicted 02 Oct-04 Oct 090/090/085
90 Day Mean 01 Oct 082

V. Geomagnetic A Indices
Observed Afr/Ap 30 Sep 006/008
Estimated Afr/Ap 01 Oct 017/021
Predicted Afr/Ap 02 Oct-04 Oct 008/010-008/008-006/005

VI. Geomagnetic Activity Probabilities 02 Oct-04 Oct
A. Middle Latitudes
Active 35/20/15
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 10/20/15
Minor Storm 25/25/20
Major-severe storm 45/25/20