Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 11 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 284 Issued at 2200Z on 11 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 10/2302Z. There are currently 3 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 (12 Oct, 13 Oct, 14 Oct).

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 416 km/s at 11/0405Z. Total IMF reached 11 nT at 11/0102Z. The maximum southward component of Bz reached -9 nT at 11/0124Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 473 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to major storm levels on day one (12 Oct), quiet to active levels on day two (13 Oct) and quiet levels on day three (14 Oct).

III. Event probabilities 12 Oct-14 Oct
Class M 10/10/10
Class X 01/01/01
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 11 Oct 089
Predicted 12 Oct-14 Oct 088/086/084
90 Day Mean 11 Oct 083

V. Geomagnetic A Indices
Observed Afr/Ap 10 Oct 009/011
Estimated Afr/Ap 11 Oct 016/020
Predicted Afr/Ap 12 Oct-14 Oct 022/030-014/016-005/005

VI. Geomagnetic Activity Probabilities 12 Oct-14 Oct
A. Middle Latitudes
Active 30/30/15
Minor Storm 40/10/01
Major-severe storm 20/01/01
B. High Latitudes
Active 05/15/15
Minor Storm 20/30/20
Major-severe storm 75/40/20