Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 209 Issued at 2200Z on 28 Jul 2013

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: 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
28/1221Z from Region 1800 (S08W74). There are currently 4 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 day one (29 Jul) and expected to
be very low with a chance for a C-class flares and a slight chance for
an M-class flare on days two and three (30 Jul, 31 Jul).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: 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 521 km/s at
28/1328Z. Total IMF reached 6 nT at 28/0621Z. The maximum southward
component of Bz reached -5 nT at 27/2116Z. Electrons greater than 2 MeV
at geosynchronous orbit reached a peak level of 365 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (29 Jul, 30 Jul, 31
Jul).

III. Event probabilities 29 Jul-31 Jul
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Jul 109
Predicted 29 Jul-31 Jul 110/120/120
90 Day Mean 28 Jul 120

V. Geomagnetic A Indices
Observed Afr/Ap 27 Jul 010/010
Estimated Afr/Ap 28 Jul 007/007
Predicted Afr/Ap 29 Jul-31 Jul 005/005-004/005-004/005

VI. Geomagnetic Activity Probabilities 29 Jul-31 Jul
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 20/20/20
Major-severe storm 10/10/10