Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 10 April 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 100 Issued at 2200Z on 10 Apr 2013

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to
10/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
10/1919Z from Region 1713 (N08W88). There are currently 9 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (11
Apr, 12 Apr, 13 Apr).

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: 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 407 km/s at
10/2005Z. Total IMF reached 7 nT at 10/2049Z. The maximum southward
component of Bz reached -4 nT at 10/0725Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 478 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (11 Apr, 12 Apr, 13
Apr).

III. Event probabilities 11 Apr-13 Apr
Class M 20/20/20
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 10 Apr 148
Predicted 11 Apr-13 Apr 150/145/140
90 Day Mean 10 Apr 113

V. Geomagnetic A Indices
Observed Afr/Ap 09 Apr 004/003
Estimated Afr/Ap 10 Apr 005/005
Predicted Afr/Ap 11 Apr-13 Apr 006/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 11 Apr-13 Apr
A. Middle Latitudes
Active 10/10/10
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/20
Major-severe storm 10/10/10