Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 11 September 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 254 Issued at 2200Z on 11 Sep 2013

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to
11/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 4 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 (12
Sep, 13 Sep, 14 Sep).

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 417 km/s at
11/1705Z. Total IMF reached 7 nT at 10/2355Z. The maximum southward
component of Bz reached -5 nT at 11/0021Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 162 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to active levels on day one (12 Sep) and quiet to
active levels on day two (13 Sep) due to coronal hole high speed stream
(CH HSS) effects. Quiet to unsettled levels are expected on day three
(14 Sep) as CH HSS effects subside.

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

IV. Penticton 10.7 cm Flux
Observed 11 Sep 093
Predicted 12 Sep-14 Sep 095/095/100
90 Day Mean 11 Sep 114

V. Geomagnetic A Indices
Observed Afr/Ap 10 Sep 006/006
Estimated Afr/Ap 11 Sep 008/010
Predicted Afr/Ap 12 Sep-14 Sep 016/020-013/015-008/008

VI. Geomagnetic Activity Probabilities 12 Sep-14 Sep
A. Middle Latitudes
Active 40/30/10
Minor Storm 15/15/05
Major-severe storm 01/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 30/30/25
Major-severe storm 50/45/20