Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 July 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 207 Issued at 2200Z on 26 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: 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 (27 Jul, 28 Jul, 29 Jul).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 396 km/s at 26/0710Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 484 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (27 Jul, 29 Jul) and quiet to active levels on day two (28 Jul).

III. Event probabilities 27 Jul-29 Jul
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Jul 081
Predicted 27 Jul-29 Jul 082/082/080
90 Day Mean 26 Jul 079

V. Geomagnetic A Indices
Observed Afr/Ap 25 Jul 005/003
Estimated Afr/Ap 26 Jul 004/004
Predicted Afr/Ap 27 Jul-29 Jul 007/008-009/012-008/010

VI. Geomagnetic Activity Probabilities 27 Jul-29 Jul
A. Middle Latitudes
Active 10/30/25
Minor Storm 01/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/30/30
Major-severe storm 20/40/30