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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 298 Issued at 2200Z on 25 Oct 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 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 and a slight chance for an M-class flare on days one, two, and three (26 Oct, 27 Oct, 28 Oct).

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 379 km/s at 24/2124Z. Total IMF reached 8 nT at 25/1536Z. The maximum southward component of Bz reached -4 nT at 25/1341Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 347 pfu.

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

III. Event probabilities 26 Oct-28 Oct
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Oct 101
Predicted 26 Oct-28 Oct 100/100/102
90 Day Mean 25 Oct 083

V. Geomagnetic A Indices
Observed Afr/Ap 24 Oct 002/003
Estimated Afr/Ap 25 Oct 005/005
Predicted Afr/Ap 26 Oct-28 Oct 007/005-008/008-009/010

VI. Geomagnetic Activity Probabilities 26 Oct-28 Oct
A. Middle Latitudes
Active 15/15/25
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/30
Major-severe storm 25/25/30