Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 31 December 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 365 Issued at 2200Z on 31 Dec 2017

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: 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 (01 Jan, 02 Jan, 03 Jan).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 397 km/s at 30/2105Z. Total IMF reached 11 nT at 31/2040Z. The maximum southward component of Bz reached -7 nT at 31/2025Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 839 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (01 Jan), quiet to active levels on day two (02 Jan) and quiet to unsettled levels on day three (03 Jan).

III.  Event probabilities 01 Jan-03 Jan
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 Dec 071
Predicted   01 Jan-03 Jan 068/068/068
90 Day Mean        31 Dec 073

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Dec  002/002
Estimated Afr/Ap 31 Dec  004/006
Predicted Afr/Ap 01 Jan-03 Jan  018/025-014/015-007/008

VI.  Geomagnetic Activity Probabilities 01 Jan-03 Jan
A.  Middle Latitudes
Active                35/30/20
Minor Storm           20/15/05
Major-severe storm    05/05/01
B.  High Latitudes
Active                10/15/20
Minor Storm           25/30/25
Major-severe storm    50/45/25