Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 291 Issued at 2200Z on 18 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (19 Oct, 20 Oct, 21 Oct).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 385 km/s at 18/1507Z. Total IMF reached 12 nT at 18/0428Z. The maximum southward component of Bz reached -8 nT at 17/2117Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 432 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (19 Oct, 21 Oct) and quiet levels on day two (20 Oct).

III. Event probabilities 19 Oct-21 Oct
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Oct 076
Predicted 19 Oct-21 Oct 076/076/076
90 Day Mean 18 Oct 083

V. Geomagnetic A Indices
Observed Afr/Ap 17 Oct 006/012
Estimated Afr/Ap 18 Oct 008/010
Predicted Afr/Ap 19 Oct-21 Oct 012/012-007/008-008/010

VI. Geomagnetic Activity Probabilities 19 Oct-21 Oct
A. Middle Latitudes
Active 30/25/30
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 35/30/35