Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 July 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 203 Issued at 2200Z on 22 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 6 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 (23 Jul, 24 Jul, 25 Jul).

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 498 km/s at 22/0137Z. Total IMF reached 7 nT at 22/1010Z. The maximum southward component of Bz reached -7 nT at 22/0958Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 233 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (23 Jul), quiet to active levels on day two (24 Jul) and quiet to unsettled levels on day three (25 Jul).

III. Event probabilities 23 Jul-25 Jul
Class M 05/05/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 Jul 089
Predicted 23 Jul-25 Jul 089/087/085
90 Day Mean 22 Jul 078

V. Geomagnetic A Indices
Observed Afr/Ap 21 Jul 006/006
Estimated Afr/Ap 22 Jul 008/011
Predicted Afr/Ap 23 Jul-25 Jul 013/018-013/016-007/008

VI. Geomagnetic Activity Probabilities 23 Jul-25 Jul
A. Middle Latitudes
Active 40/35/25
Minor Storm 25/20/05
Major-severe storm 05/05/01
B. High Latitudes
Active 10/10/15
Minor Storm 25/25/30
Major-severe storm 60/50/30