Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 September 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 260 Issued at 2200Z on 17 Sep 2013

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 7 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 on days one, two, and three (18 Sep,
19 Sep, 20 Sep).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: 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
422 km/s at 16/2348Z. Total IMF reached 8 nT at 17/1944Z. The maximum
southward component of Bz reached -6 nT at 17/0248Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 170 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (18 Sep) and quiet to
unsettled levels on days two and three (19 Sep, 20 Sep).

III. Event probabilities 18 Sep-20 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Sep 099
Predicted 18 Sep-20 Sep 100/100/105
90 Day Mean 17 Sep 112

V. Geomagnetic A Indices
Observed Afr/Ap 16 Sep 006/005
Estimated Afr/Ap 17 Sep 006/008
Predicted Afr/Ap 18 Sep-20 Sep 010/012-007/010-007/008

VI. Geomagnetic Activity Probabilities 18 Sep-20 Sep
A. Middle Latitudes
Active 35/25/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/25/15
Minor Storm 35/35/25
Major-severe storm 45/25/10