Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 December 2020

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 353 Issued at 2200Z on 18 Dec 2020

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 0 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 Dec, 20 Dec, 21 Dec).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 301 km/s at 18/1807Z. Total IMF reached 7 nT at 18/1113Z. The maximum southward component of Bz reached -6 nT at 18/1356Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 251 pfu.

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

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

IV. Penticton 10.7 cm Flux
Observed 18 Dec 082
Predicted 19 Dec-21 Dec 082/082/082
90 Day Mean 18 Dec 082

V. Geomagnetic A Indices
Observed Afr/Ap 17 Dec 002/000
Estimated Afr/Ap 18 Dec 002/003
Predicted Afr/Ap 19 Dec-21 Dec 005/005-006/005-010/012

VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec
A. Middle Latitudes
Active 10/10/30
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/15
Minor Storm 20/20/30
Major-severe storm 10/10/40