Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 December 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 352 Issued at 2200Z on 18 Dec 2018

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 unsettled levels for the past 24 hours. Solar wind speed reached a peak of 461 km/s at 18/1631Z. Total IMF reached 7 nT at 18/0018Z. The maximum southward component of Bz reached -5 nT at 18/1300Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 170 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (19 Dec) and quiet levels on days two and three (20 Dec, 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 070
Predicted   19 Dec-21 Dec 070/070/070
90 Day Mean        18 Dec 069

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Dec  005/003
Estimated Afr/Ap 18 Dec  007/008
Predicted Afr/Ap 19 Dec-21 Dec  008/008-005/005-006/005

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