Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 December 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 352 Issued at 2200Z on 18 Dec 2017

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 to active levels for the past 24 hours. Solar wind speed reached a peak of 671 km/s at 18/0329Z. Total IMF reached 10 nT at 17/2133Z. The maximum southward component of Bz reached -8 nT at 17/2131Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 5978 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (19 Dec), unsettled levels on day two (20 Dec) and quiet to unsettled 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 072
Predicted   19 Dec-21 Dec 072/072/072
90 Day Mean        18 Dec 075

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Dec  016/023
Estimated Afr/Ap 18 Dec  016/021
Predicted Afr/Ap 19 Dec-21 Dec  015/015-011/012-007/008

VI.  Geomagnetic Activity Probabilities 19 Dec-21 Dec
A.  Middle Latitudes
Active                25/20/15
Minor Storm           10/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/10
Minor Storm           30/25/20
Major-severe storm    35/30/20