Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 27 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 300 Issued at 2200Z on 27 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity has been at low levels for the past 24 hours.The largest solar event of the period was a C8 event observed at 27/0608Z from Region 2887 (S26E04). There are currently 5 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (28 Oct, 29 Oct, 30 Oct).

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 417 km/s at 27/0528Z. Total IMF reached 7 nT at 26/2136Z. The maximum southward component of Bz reached -2 nT at 27/0116Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 138 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (28 Oct), quiet to unsettled levels on day two (29 Oct) and quiet to active levels on day three (30 Oct).

III. Event probabilities 28 Oct-30 Oct
Class M 15/15/15
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 27 Oct 111
Predicted 28 Oct-30 Oct 111/112/110
90 Day Mean 27 Oct 084

V. Geomagnetic A Indices
Observed Afr/Ap 26 Oct 003/003
Estimated Afr/Ap 27 Oct 004/004
Predicted Afr/Ap 28 Oct-30 Oct 006/005-006/008-009/010

VI. Geomagnetic Activity Probabilities 28 Oct-30 Oct
A. Middle Latitudes
Active 10/15/30
Minor Storm 01/05/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/30
Major-severe storm 15/25/40