Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 January 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 20 Issued at 2200Z on 20 Jan 2021

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 20/1253Z from Region 2798 (S17E51). There are currently 2 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 on days one, two, and three (21 Jan, 22 Jan, 23 Jan).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagneticfield has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 414 km/s at 20/0141Z. Total IMF reached 8 nT at 19/2142Z. The maximum southward component of Bz reached -7 nT at 20/0604Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 187 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expectedto be at quiet to active levels on day one (21 Jan), quiet to unsettled levels on day two (22 Jan) and quiet levels on day three (23 Jan).

III. Event probabilities 21 Jan-23 Jan
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Jan 077
Predicted 21 Jan-23 Jan 080/080/080
90 Day Mean 20 Jan 085

V. Geomagnetic A Indices
Observed Afr/Ap 19 Jan 006/003
Estimated Afr/Ap 20 Jan 011/012
Predicted Afr/Ap 21 Jan-23 Jan 011/014-009/010-007/008

VI. Geomagnetic Activity Probabilities 21 Jan-23 Jan
A. Middle Latitudes
Active 35/30/20
Minor Storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor Storm 30/30/30
Major-severe storm 45/35/25