Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 290 Issued at 2200Z on 17 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on day one (18 Oct) and expected to be very low with a slight chance for a C-class flare on days two and three (19 Oct, 20 Oct).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 419 km/s at 17/0111Z. Total IMF reached 10 nT at 17/0111Z. The maximum southward component of Bz reached -8 nT at 17/1038Z. Electrons greater than 2 MeV at geosynchronous orbit reacheda peak level of 251 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (18 Oct, 19 Oct) and quiet levels on day three (20 Oct).

III. Event probabilities 18 Oct-20 Oct
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Oct 077
Predicted 18 Oct-20 Oct 078/080/080
90 Day Mean 17 Oct 083

V. Geomagnetic A Indices
Observed Afr/Ap 16 Oct 003/005
Estimated Afr/Ap 17 Oct 008/010
Predicted Afr/Ap 18 Oct-20 Oct 009/012-012/012-007/008

VI. Geomagnetic Activity Probabilities 18 Oct-20 Oct
A. Middle Latitudes
Active 30/30/25
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/30
Major-severe storm 35/35/30