Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 23 December 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 357 Issued at 2200Z on 23 Dec 2017

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: 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 with a slight chance for a C-class flare on days one, two, and three (24 Dec, 25 Dec, 26 Dec).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 404 km/s at 23/1536Z. Total IMF reached 8 nT at 23/1219Z. The maximum southward component of Bz reached -6 nT at 23/0639Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2813 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (24 Dec, 25 Dec) and quiet to unsettled levels on day three (26 Dec).

III.  Event probabilities 24 Dec-26 Dec
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 Dec 076
Predicted   24 Dec-26 Dec 075/075/075
90 Day Mean        23 Dec 075

V.  Geomagnetic A Indices
Observed Afr/Ap 22 Dec  002/001
Estimated Afr/Ap 23 Dec  005/005
Predicted Afr/Ap 24 Dec-26 Dec  010/012-011/012-007/008

VI.  Geomagnetic Activity Probabilities 24 Dec-26 Dec
A.  Middle Latitudes
Active                30/30/20
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/20/20
Minor Storm           30/35/30
Major-severe storm    40/35/25