Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 December 2016

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 353 Issued at 2200Z on 18 Dec 2016

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 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare 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 467 km/s at 18/0245Z. Total IMF reached 11 nT at 17/2308Z. The maximum southward component of Bz reached -9 nT at 17/2311Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1565 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (19 Dec, 20 Dec) and unsettled to minor storm 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 073/073/073
90 Day Mean 18 Dec 082

V. Geomagnetic A Indices
Observed Afr/Ap 17 Dec 003/003
Estimated Afr/Ap 18 Dec 010/010
Predicted Afr/Ap 19 Dec-21 Dec 011/015-012/015-017/025

VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec
A. Middle Latitudes
Active 30/30/40
Minor Storm 10/10/25
Major-severe storm 01/01/05
B. High Latitudes
Active 15/15/10
Minor Storm 30/30/25
Major-severe storm 40/40/60