Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 December 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 362 Issued at 2200Z on 28 Dec 2018

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: 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 (29 Dec, 30 Dec, 31 Dec).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 645 km/s at 28/1959Z. Total IMF reached 13 nT at 28/0508Z. The maximum southward component of Bz reached -11 nT at 28/0606Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (29 Dec) and quiet to unsettled levels on days two and three (30 Dec, 31 Dec).

III. Event probabilities 29 Dec-31 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Dec 069
Predicted 29 Dec-31 Dec 069/069/069
90 Day Mean 28 Dec 070

V. Geomagnetic A Indices
Observed Afr/Ap 27 Dec 005/003
Estimated Afr/Ap 28 Dec 020/024
Predicted Afr/Ap 29 Dec-31 Dec 015/015-010/010-008/008

VI. Geomagnetic Activity Probabilities 29 Dec-31 Dec
A. Middle Latitudes
Active 30/15/10
Minor Storm 10/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/30/25
Major-severe storm 40/25/20