Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 8 April 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 98 Issued at 2200Z on 08 Apr 2013

IA. Analysis of Solar Active Regions and Activity from 07/2100Z to
08/2100Z: Solar activity has been at low levels for the past 24
hours. The largest event of the period was a C1 x-ray event at 08/1653
UTC. There are currently 8 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 (09 Apr,
10 Apr, 11 Apr).

IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z: 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 408 km/s at
08/0524Z. Total IMF reached 6 nT at 08/0522Z. The maximum southward
component of Bz reached -2 nT at 08/0712Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 341 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (09 Apr, 10 Apr)
and quiet levels on day three (11 Apr).

III. Event probabilities 09 Apr-11 Apr
Class M 20/20/20
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 08 Apr 139
Predicted 09 Apr-11 Apr 135/130/130
90 Day Mean 08 Apr 114

V. Geomagnetic A Indices
Observed Afr/Ap 07 Apr 005/006
Estimated Afr/Ap 08 Apr 003/005
Predicted Afr/Ap 09 Apr-11 Apr 007/008-006/008-006/005

VI. Geomagnetic Activity Probabilities 09 Apr-11 Apr
A. Middle Latitudes
Active 15/15/10
Minor Storm 05/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/20
Minor Storm 25/25/20
Major-severe storm 20/20/10