Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 December 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 358 Issued at 2200Z on 24 Dec 2017

IA.  Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: 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 (25 Dec, 26 Dec, 27 Dec).

IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 606 km/s at 24/1556Z. Total IMF reached 14 nT at 24/0722Z. The maximum southward component of Bz reached -9 nT at 24/0959Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1434 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (25 Dec), quiet to unsettled levels on day two (26 Dec) and quiet levels on day three (27 Dec).

III.  Event probabilities 25 Dec-27 Dec
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           24 Dec 076
Predicted   25 Dec-27 Dec 075/075/075
90 Day Mean        24 Dec 074

V.  Geomagnetic A Indices
Observed Afr/Ap 23 Dec  004/004
Estimated Afr/Ap 24 Dec  011/012
Predicted Afr/Ap 25 Dec-27 Dec  011/012-007/008-006/005

VI.  Geomagnetic Activity Probabilities 25 Dec-27 Dec
A.  Middle Latitudes
Active                30/20/15
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/20/15
Minor Storm           35/30/20
Major-severe storm    35/25/20