Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 July 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 206 Issued at 2200Z on 25 Jul 2021

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: 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 (26 Jul, 27 Jul, 28 Jul).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 471 km/s at 25/0559Z. Total IMF reached 5 nT at 24/2146Z. The maximum southward component of Bz reached -2 nT at 25/0250Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 310 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (26 Jul, 27 Jul) and quiet to active levels on day three (28 Jul).

III. Event probabilities 26 Jul-28 Jul
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Jul 082
Predicted 26 Jul-28 Jul 082/082/082
90 Day Mean 25 Jul 079

V. Geomagnetic A Indices
Observed Afr/Ap 24 Jul 005/004
Estimated Afr/Ap 25 Jul 004/005
Predicted Afr/Ap 26 Jul-28 Jul 005/005-005/005-009/012

VI. Geomagnetic Activity Probabilities 26 Jul-28 Jul
A. Middle Latitudes
Active 10/10/30
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/30
Major-severe storm 15/15/40