Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 4 September 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 247 Issued at 2200Z on 04 Sep 2021

IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 5 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 on days one, two, and three (05 Sep, 06 Sep, 07 Sep).

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 447 km/s at 04/0817Z. Total IMF reached 6 nT at 04/0200Z. The maximum southward component of Bz reached -5 nT at 03/2140Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 966 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (05 Sep, 06 Sep) and quiet levels on day three (07 Sep).

III. Event probabilities 05 Sep-07 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 04 Sep 087
Predicted 05 Sep-07 Sep 086/084/082
90 Day Mean 04 Sep 080

V. Geomagnetic A Indices
Observed Afr/Ap 03 Sep 006/008
Estimated Afr/Ap 04 Sep 006/005
Predicted Afr/Ap 05 Sep-07 Sep 008/010-008/008-006/005

VI. Geomagnetic Activity Probabilities 05 Sep-07 Sep
A. Middle Latitudes
Active 25/20/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/20
Major-severe storm 35/25/20