Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 16 September 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 259 Issued at 2200Z on 16 Sep 2015

IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C7 event observed at 16/1920Z from Region 2415 (S20W02). There are currently 4 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 (17 Sep, 18 Sep, 19 Sep).

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 533 km/s at 16/0553Z. Total IMF reached 6 nT at 16/1750Z. The maximum southward component of Bz reached -5 nT at 15/2151Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 8045 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one, two, and three (17 Sep, 18 Sep, 19 Sep).

III. Event probabilities 17 Sep-19 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 16 Sep 109
Predicted 17 Sep-19 Sep 110/110/110
90 Day Mean 16 Sep 105

V. Geomagnetic A Indices
Observed Afr/Ap 15 Sep 017/021
Estimated Afr/Ap 16 Sep 009/012
Predicted Afr/Ap 17 Sep-19 Sep 008/008-008/008-007/008

VI. Geomagnetic Activity Probabilities 17 Sep-19 Sep
A. Middle Latitudes
Active 20/20/20
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/20
Minor Storm 30/30/30
Major-severe storm 25/25/25