Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 September 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 269 Issued at 2200Z on 25 Sep 2020

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (26 Sep, 27 Sep, 28 Sep).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 544 km/s at 25/0916Z. Total IMF reached 7 nT at 25/1417Z. The maximum southward component of Bz reached -6 nT at 25/2100Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 6990 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (26 Sep, 27 Sep) and quiet to minor storm levels on day three (28 Sep).

III. Event probabilities 26 Sep-28 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Sep 073
Predicted 26 Sep-28 Sep 073/073/073
90 Day Mean 25 Sep 070

V. Geomagnetic A Indices
Observed Afr/Ap 24 Sep 011/018
Estimated Afr/Ap 25 Sep 015/018
Predicted Afr/Ap 26 Sep-28 Sep 012/012-011/012-011/016

VI. Geomagnetic Activity Probabilities 26 Sep-28 Sep
A. Middle Latitudes
Active 35/35/40
Minor Storm 20/20/25
Major-severe storm 05/05/05
B. High Latitudes
Active 10/10/10
Minor Storm 30/30/25
Major-severe storm 50/50/60