Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 September 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 255 Issued at 2200Z on 12 Sep 2015

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 11/2137Z from Region 2414 (S10W20). There are currently 6 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (13 Sep, 14 Sep, 15 Sep).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 658 km/s at 12/0023Z. Total IMF reached 8 nT at 11/2113Z. The maximum southward component of Bz reached -7 nT at 11/2134Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 10410 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on days one and three (13 Sep, 15 Sep) and quiet to active levels on day two (14 Sep).

III. Event probabilities 13 Sep-15 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 Sep 099
Predicted 13 Sep-15 Sep 100/105/105
90 Day Mean 12 Sep 107

V. Geomagnetic A Indices
Observed Afr/Ap 11 Sep 036/053
Estimated Afr/Ap 12 Sep 023/030
Predicted Afr/Ap 13 Sep-15 Sep 019/025-012/015-016/020

VI. Geomagnetic Activity Probabilities 13 Sep-15 Sep
A. Middle Latitudes
Active 35/30/30
Minor Storm 20/10/15
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/30/25
Major-severe storm 50/40/45