Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 September 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 272 Issued at 2200Z on 28 Sep 2020

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (29 Sep, 30 Sep, 01 Oct).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at active to major storm levels for the past 24 hours. Solar wind speed reached a peak of 660 km/s at 28/0016Z. Total IMF reached 8 nT at 27/2125Z. The maximum southward component of Bz reached -6 nT at 27/2135Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 15792 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels with an outside chance for a major storm on day one (29 Sep), quiet to minor storm levels on day two (30 Sep) and quiet to active levels on day three (01 Oct).

III. Event probabilities 29 Sep-01 Oct
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Sep 074
Predicted 29 Sep-01 Oct 074/074/074
90 Day Mean 28 Sep 071

V. Geomagnetic A Indices
Observed Afr/Ap 27 Sep 016/026
Estimated Afr/Ap 28 Sep 025/038
Predicted Afr/Ap 29 Sep-01 Oct 026/038-020/025-013/015

VI. Geomagnetic Activity Probabilities 29 Sep-01 Oct
A. Middle Latitudes
Active 30/40/30
Minor Storm 40/30/15
Major-severe storm 25/10/01
B. High Latitudes
Active 05/05/15
Minor Storm 15/20/30
Major-severe storm 80/75/45