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

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 299 Issued at 2200Z on 26 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 26/0247Z. There are currently 6 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a chance for M-class flares and a slight chance for an X-class flare on day one (27 Oct) and likely to be low with a slight chance for an M-class flare on days two and three (28 Oct, 29 Oct).

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 of Bz reached -4 nT at 26/0054Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 152 pfu.

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

III. Event probabilities 27 Oct-29 Oct
Class M 25/15/15
Class X 10/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Oct 109
Predicted 27 Oct-29 Oct 108/110/110
90 Day Mean 26 Oct 083

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

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