Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 December 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 355 Issued at 2200Z on 21 Dec 2018

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 (22 Dec, 23 Dec, 24 Dec).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 544 km/s at 20/2234Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 279 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (22 Dec, 23 Dec) and quiet to unsettled levels on day three (24 Dec).

III.  Event probabilities 22 Dec-24 Dec
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Dec 071
Predicted   22 Dec-24 Dec 071/071/071
90 Day Mean        21 Dec 069

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Dec  009/006
Estimated Afr/Ap 21 Dec  005/005
Predicted Afr/Ap 22 Dec-24 Dec  006/005-006/005-007/008

VI.  Geomagnetic Activity Probabilities 22 Dec-24 Dec
A.  Middle Latitudes
Active                10/10/20
Minor Storm           01/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           15/15/25
Major-severe storm    15/15/25