Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 11 December 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 345 Issued at 2200Z on 11 Dec 2015

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C5 event observed at 11/1716Z from Region 2465 (S05E09). There are currently 6 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (12 Dec, 13 Dec, 14 Dec).

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at unsettled to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 702 km/s at 11/0207Z. Total IMF reached 7 nT at 10/2116Z. The maximum southward component of Bz reached -6 nT at 10/2157Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 6095 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (12 Dec, 13 Dec) and quiet to unsettled levels on day three (14 Dec).

III. Event probabilities 12 Dec-14 Dec
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 11 Dec 114
Predicted 12 Dec-14 Dec 115/115/120
90 Day Mean 11 Dec 107

V. Geomagnetic A Indices
Observed Afr/Ap 10 Dec 018/023
Estimated Afr/Ap 11 Dec 018/022
Predicted Afr/Ap 12 Dec-14 Dec 013/016-011/012-010/010

VI. Geomagnetic Activity Probabilities 12 Dec-14 Dec
A. Middle Latitudes
Active 25/15/15
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/20
Minor Storm 35/30/25
Major-severe storm 30/20/20