Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 December 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 359 Issued at 2200Z on 25 Dec 2019

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (26 Dec, 27 Dec, 28 Dec).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 377 km/s at 25/0135Z. Total IMF reached 8 nT at 25/1923Z. The maximum southward component of Bz reached -4 nT at 25/1714Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 462 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (26 Dec) and quiet levels on days two and three (27 Dec, 28 Dec).

III. Event probabilities 26 Dec-28 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Dec 072
Predicted 26 Dec-28 Dec 072/072/072
90 Day Mean 25 Dec 069

V. Geomagnetic A Indices
Observed Afr/Ap 24 Dec 002/002
Estimated Afr/Ap 25 Dec 003/006
Predicted Afr/Ap 26 Dec-28 Dec 008/008-005/005-006/005

VI. Geomagnetic Activity Probabilities 26 Dec-28 Dec
A. Middle Latitudes
Active 15/10/10
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor Storm 25/20/20
Major-severe storm 25/20/10