Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 July 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 204 Issued at 2200Z on 23 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: 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 (24 Jul, 25 Jul, 26 Jul).

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 457 km/s at 22/2119Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 245 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (24 Jul) and quiet levels on days two and three (25 Jul, 26 Jul).

III. Event probabilities 24 Jul-26 Jul
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 23 Jul 087
Predicted 24 Jul-26 Jul 087/085/085
90 Day Mean 23 Jul 078

V. Geomagnetic A Indices
Observed Afr/Ap 22 Jul 009/010
Estimated Afr/Ap 23 Jul 008/011
Predicted Afr/Ap 24 Jul-26 Jul 010/012-006/005-005/005

VI. Geomagnetic Activity Probabilities 24 Jul-26 Jul
A. Middle Latitudes
Active 35/10/10
Minor Storm 20/05/01
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/20/20
Major-severe storm 50/20/15