Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 September 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 264 Issued at 2200Z on 21 Sep 2013

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
21/0924Z from Region 1850 (N08E52). There are currently 5 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low on days
one, two, and three (22 Sep, 23 Sep, 24 Sep).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: 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
470 km/s at 20/2137Z. Total IMF reached 5 nT at 21/1732Z. The maximum
southward component of Bz reached -4 nT at 21/0722Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 2810 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (22 Sep) and quiet to unsettled levels
on days two and three (23 Sep, 24 Sep).

III. Event probabilities 22 Sep-24 Sep
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Sep 110
Predicted 22 Sep-24 Sep 115/118/115
90 Day Mean 21 Sep 111

V. Geomagnetic A Indices
Observed Afr/Ap 20 Sep 005/006
Estimated Afr/Ap 21 Sep 008/007
Predicted Afr/Ap 22 Sep-24 Sep 005/005-008/008-008/008

VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep
A. Middle Latitudes
Active 05/10/10
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/25/25
Major-severe storm 05/10/10