Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 September 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 268 Issued at 2200Z on 24 Sep 2020

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: 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 (25 Sep, 26 Sep, 27 Sep).

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 535 km/s at 24/0853Z. Total IMF reached 11 nT at 24/0240Z. The maximum southward component of Bz reached -9 nT at 24/0453Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1232 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (25 Sep) and quiet to active levels on days two and three (26 Sep, 27 Sep).

III. Event probabilities 25 Sep-27 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 24 Sep 074
Predicted 25 Sep-27 Sep 074/074/074
90 Day Mean 24 Sep 070

V. Geomagnetic A Indices
Observed Afr/Ap 23 Sep 010/011
Estimated Afr/Ap 24 Sep 017/022
Predicted Afr/Ap 25 Sep-27 Sep 013/018-014/016-012/014

VI. Geomagnetic Activity Probabilities 25 Sep-27 Sep
A. Middle Latitudes
Active 35/35/40
Minor Storm 20/10/20
Major-severe storm 01/01/05
B. High Latitudes
Active 10/10/10
Minor Storm 25/30/25
Major-severe storm 50/45/60