Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 August 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 231 Issued at 2200Z on 19 Aug 2021

IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 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, two, and three (20 Aug, 21 Aug, 22 Aug).

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 432 km/s at 19/0050Z. Total IMF reached 6 nT at 19/1512Z. The maximum southward component of Bz reached -6 nT at 19/1447Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 448 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (20 Aug) and quiet to unsettled levels on days two and three (21 Aug, 22 Aug).

III. Event probabilities 20 Aug-22 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 19 Aug 075
Predicted 20 Aug-22 Aug 075/073/073
90 Day Mean 19 Aug 079

V. Geomagnetic A Indices
Observed Afr/Ap 18 Aug 006/006
Estimated Afr/Ap 19 Aug 005/005
Predicted Afr/Ap 20 Aug-22 Aug 005/005-008/008-008/008

VI. Geomagnetic Activity Probabilities 20 Aug-22 Aug
A. Middle Latitudes
Active 10/20/20
Minor Storm 01/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/30/30
Major-severe storm 15/25/25