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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 216 Issued at 2200Z on 04 Aug 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 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one and two (05 Aug, 06 Aug) and expected to be very low on day three (07 Aug).

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 442 km/s at 03/2322Z. Total IMF reached 7 nT at 03/2116Z. The maximum southward component of Bz reached -6 nT at 03/2114Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1132 pfu.

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

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

IV. Penticton 10.7 cm Flux
Observed 04 Aug 071
Predicted 05 Aug-07 Aug 072/072/070
90 Day Mean 04 Aug 079

V. Geomagnetic A Indices
Observed Afr/Ap 03 Aug 013/014
Estimated Afr/Ap 04 Aug 005/005
Predicted Afr/Ap 05 Aug-07 Aug 007/008-010/012-008/008

VI. Geomagnetic Activity Probabilities 05 Aug-07 Aug
A. Middle Latitudes
Active 20/30/20
Minor Storm 05/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor Storm 25/30/30
Major-severe storm 25/40/25