Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 September 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 271 Issued at 2200Z on 27 Sep 2020

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: 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 (28 Sep, 29 Sep, 30 Sep).

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 613 km/s at 27/2051Z. Total IMF reached 10 nT at 27/1959Z. The maximum southward component of Bz reached -9 nT at 27/2008Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 16736 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to major storm levels on days one and two (28 Sep, 29 Sep) and quiet to minor storm levels on day three (30 Sep).

III. Event probabilities 28 Sep-30 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 27 Sep 074
Predicted 28 Sep-30 Sep 072/072/072
90 Day Mean 27 Sep 071

V. Geomagnetic A Indices
Observed Afr/Ap 26 Sep 018/022
Estimated Afr/Ap 27 Sep 015/020
Predicted Afr/Ap 28 Sep-30 Sep 027/038-026/038-020/026

VI. Geomagnetic Activity Probabilities 28 Sep-30 Sep
A. Middle Latitudes
Active 30/30/40
Minor Storm 45/40/30
Major-severe storm 25/25/10
B. High Latitudes
Active 05/05/05
Minor Storm 15/15/20
Major-severe storm 85/80/75